Topic: Pollination Biology; Subtopic: Mutualism in Fig and Wasp
Keyword Definitions:
• Mutualism: A biological interaction where both species benefit.
• Pollination: Transfer of pollen from anther to stigma for fertilization.
• Syconium: The fleshy inflorescence of fig enclosing multiple flowers.
• Fig Wasp: A small insect involved in pollination of fig trees while reproducing inside the syconium.
• Symbiosis: Close association between two different species for mutual benefit.
Lead Question - 2025
Given below are two statements:
Statement I: Fig fruit is a non-vegetarian fruit as it has enclosed fig wasps in it.
Statement II: Fig wasp and fig tree exhibit mutual relationship as fig wasp completes its life cycle in fig fruit and fig fruit gets pollinated by fig wasp.
In the light of the above statements, choose the most appropriate answer from the options given below:
(1) Both Statement I and Statement II are correct
(2) Both Statement I and Statement II are incorrect
(3) Statement I is correct but Statement II is incorrect
(4) Statement I is incorrect but Statement II is correct
Explanation:
Statement I is incorrect because fig fruit, though it develops with fig wasp interaction, is not non-vegetarian. It is a plant-based fruit. Statement II is correct because the fig wasp and fig tree show a classic example of mutualism—each depending on the other for pollination and reproduction. Hence, the correct answer is (4) Statement I is incorrect but Statement II is correct. This interaction ensures reproductive success for both species, illustrating ecological interdependence.
Guessed Questions:
1. Which type of pollination is exhibited by the fig and fig wasp relationship?
(1) Anemophily
(2) Entomophily
(3) Hydrophily
(4) Ornithophily
Explanation: The fig and fig wasp show entomophily, i.e., pollination by insects. The wasp enters the fig’s syconium to lay eggs and simultaneously helps transfer pollen, making it a mutualistic insect-based pollination type.
2. The fruit of fig (Ficus carica) is botanically termed as:
(1) Drupe
(2) Syconus
(3) Achene
(4) Berry
Explanation: The fig fruit is a syconus, which is a multiple fruit derived from an inflorescence where flowers are enclosed within a hollow receptacle. It develops through pollination assisted by the fig wasp.
3. In the fig–fig wasp relationship, the wasp gains:
(1) Shelter only
(2) Food and shelter
(3) Only food
(4) Protection only
Explanation: The wasp gains both food and shelter as it lays eggs inside the fig’s syconium, where larvae feed and grow, ensuring survival, while the plant benefits through pollination.
4. Which of the following represents a mutualistic interaction?
(1) Fig and fig wasp
(2) Tapeworm and human
(3) Cuscuta and host
(4) Malarial parasite and man
Explanation: The fig and fig wasp relationship is a perfect example of mutualism, where both species gain benefits—wasp gets a site for reproduction, and fig achieves pollination.
5. The reproductive structure of fig involved in wasp interaction is called:
(1) Pericarp
(2) Syconium
(3) Capsule
(4) Carpel
Explanation: The fig’s syconium is a fleshy hollow receptacle that encloses numerous flowers inside. It is within this structure that the fig wasp enters and performs pollination while laying eggs.
6. Which one is the correct example of obligatory mutualism?
(1) Orchid and bee
(2) Fig and fig wasp
(3) Coral and zooxanthellae
(4) Termite and flagellates
Explanation: The relationship between fig and fig wasp is an example of obligatory mutualism as both are entirely dependent on each other for reproduction and pollination, representing coevolutionary adaptation.
7. Assertion–Reason Type:
Assertion (A): The fig and fig wasp show coevolution.
Reason (R): Both species have developed structural and behavioral adaptations for mutual reproduction.
(1) Both A and R are true, and R is the correct explanation of A
(2) Both A and R are true, but R is not the correct explanation
(3) A is true, R is false
(4) A is false, R is true
Explanation: Both are true, and R explains A correctly. The fig and fig wasp co-evolved, each adapting specifically for pollination and reproduction, confirming (1) as correct.
8. Matching Type:
Match the following:
A. Fig and fig wasp — (i) Mutualism
B. Cuscuta and host — (ii) Parasitism
C. Lichen — (iii) Symbiosis
D. Barnacles on whale — (iv) Commensalism
(1) A-(i), B-(ii), C-(iii), D-(iv)
(2) A-(ii), B-(i), C-(iv), D-(iii)
(3) A-(iv), B-(iii), C-(ii), D-(i)
(4) A-(i), B-(iii), C-(ii), D-(iv)
Explanation: The correct matching is A-(i), B-(ii), C-(iii), D-(iv). Fig–fig wasp (mutualism), Cuscuta–host (parasitism), Lichen (symbiosis), and Barnacles–whale (commensalism) represent distinct ecological relationships.
9. Fill in the Blank:
The fig wasp enters the fig through a small natural opening called ________.
(1) Stigma
(2) Ostiole
(3) Style
(4) Micropyle
Explanation: The fig wasp enters the fig’s syconium through the ostiole, a small natural pore. This adaptation allows the wasp to access the inner flowers, enabling pollination and egg deposition.
10. Choose the Correct Statements:
Statement I: Fig wasps only pollinate male figs.
Statement II: Female wasps deposit eggs in the ovules inside the fig.
(1) Both statements are correct
(2) Both statements are incorrect
(3) Statement I is incorrect, but Statement II is correct
(4) Statement I is correct, but Statement II is incorrect
Explanation: Statement I is incorrect because fig wasps pollinate both male and female figs. Statement II is correct as female wasps lay eggs inside ovules, aiding in the pollination process. Correct answer: (3).
Topic: Floral Symmetry; Subtopic: Actinomorphic and Zygomorphic Flowers
Keyword Definitions:
Zygomorphic flower: A flower that can be divided into two equal halves only along one specific vertical plane.
Actinomorphic flower: A flower that can be divided into two equal halves along any vertical plane passing through the center.
Symmetry: The arrangement of floral parts with respect to the axis of the flower.
Corolla: The whorl of petals in a flower, often brightly colored and involved in pollination.
Lead Question - 2025
Which of the following is an example of a zygomorphic flower:
(1) Petunia
(2) Datura
(3) Pea
(4) Chilli
Explanation:
Zygomorphic flowers, such as those found in Pea (Pisum sativum), have bilateral symmetry and can be divided into equal halves only along a single plane. This arrangement helps in specialized pollination by insects. Actinomorphic flowers like Datura or Petunia show radial symmetry. Hence, Pea is the correct example. Answer: (3) Pea.
Guessed Questions:
1. Which type of floral symmetry is shown by Datura?
(1) Actinomorphic
(2) Zygomorphic
(3) Asymmetric
(4) Irregular
Explanation: Datura exhibits actinomorphic symmetry, meaning it can be divided into two equal halves along any vertical plane passing through the center. Such flowers attract a variety of pollinators. Answer: (1) Actinomorphic.
2. Flowers of which plant show bilateral symmetry?
(1) Hibiscus
(2) Pea
(3) Mustard
(4) Lily
Explanation: Bilateral symmetry, or zygomorphy, is found in Pea flowers. They are adapted for pollination by specific pollinators due to their structure, including standard, wings, and keel petals. Answer: (2) Pea.
3. Zygomorphic flowers are characteristic of which plant family?
(1) Solanaceae
(2) Fabaceae
(3) Liliaceae
(4) Brassicaceae
Explanation: The Fabaceae (Leguminosae) family, including Pea and Bean, shows zygomorphic flowers with a papilionaceous corolla having distinct standard, wings, and keel petals. Answer: (2) Fabaceae.
4. Actinomorphic symmetry is found in:
(1) Pea
(2) Gulmohar
(3) Datura
(4) Clitoria
Explanation: Datura flowers are actinomorphic, with all floral parts arranged radially around the axis. This allows multiple planes of symmetry, unlike the bilateral symmetry of zygomorphic flowers. Answer: (3) Datura.
5. Which of the following represents an asymmetric flower?
(1) Pea
(2) Canna
(3) Datura
(4) Mustard
Explanation: Canna flowers are asymmetric, meaning they cannot be divided into two equal halves in any plane. This irregular symmetry is rare among flowering plants. Answer: (2) Canna.
6. In papilionaceous corolla, which petal is the largest and outermost?
(1) Keel
(2) Wing
(3) Standard
(4) Sepal
Explanation: In papilionaceous corolla, found in Fabaceae, the largest petal is the standard or vexillum, which helps attract pollinators and protects other floral parts. Answer: (3) Standard.
Assertion–Reason Type Question:
Assertion (A): Zygomorphic flowers show bilateral symmetry.
Reason (R): All zygomorphic flowers can be divided into two equal halves along multiple planes.
(1) Both A and R are true and R is the correct explanation of A
(2) Both A and R are true but R is not the correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Explanation: Zygomorphic flowers exhibit bilateral symmetry and can be divided into equal halves only along a single plane, not multiple planes. Hence, R is false. Answer: (3) A is true but R is false.
Matching Type Question:
Match the following pairs:
List I – Flower | List II – Type of Symmetry
A. Pea | (i) Asymmetric
B. Datura | (ii) Actinomorphic
C. Canna | (iii) Zygomorphic
(1) A–iii, B–ii, C–i
(2) A–ii, B–i, C–iii
(3) A–i, B–iii, C–ii
(4) A–iii, B–i, C–ii
Explanation: Pea has zygomorphic symmetry, Datura is actinomorphic, and Canna is asymmetric. Answer: (1) A–iii, B–ii, C–i.
Fill in the Blanks:
In a zygomorphic flower, the floral parts are arranged such that the flower can be divided into two equal halves only along ________ plane.
(1) One
(2) Two
(3) Three
(4) Many
Explanation: Zygomorphic flowers possess bilateral symmetry, hence they can be divided into equal halves along only one vertical plane, aiding in specialized pollination. Answer: (1) One.
Choose the Correct Statements:
Statement I: Actinomorphic flowers can be divided into equal halves by only one plane.
Statement II: Zygomorphic flowers can be divided into two equal halves only along a single plane.
(1) Both statements are true
(2) Only Statement I is true
(3) Only Statement II is true
(4) Both statements are false
Explanation: Actinomorphic flowers are radially symmetrical and can be divided along multiple planes, while zygomorphic flowers are bilaterally symmetrical and divide along one plane. Hence, only Statement II is correct. Answer: (3) Only Statement II is true.
Topic: Female Gametophyte Development; Subtopic: Megasporogenesis and Megagametogenesis
Keyword Definitions:
Megaspore mother cell (MMC): A diploid cell in the ovule that undergoes meiosis to form megaspores.
Meiosis: A reductional division producing haploid cells from diploid cells.
Mitosis: An equational cell division resulting in two genetically identical daughter cells.
Female gametophyte: Also called embryo sac, the haploid structure formed from megaspore that develops into egg apparatus.
Lead Question - 2025
How many meiotic and mitotic divisions need to occur for the development of a mature female gametophyte from the megaspore mother cell in an angiosperm plant?
(1) 2 Meiosis and 3 Mitosis
(2) 1 Meiosis and 2 Mitosis
(3) 1 Meiosis and 3 Mitosis
(4) No Meiosis and 2 Mitosis
Explanation:
A diploid megaspore mother cell (2n) undergoes one meiotic division to produce four haploid megaspores. Out of these, three degenerate and one functional megaspore undergoes three mitotic divisions forming an 8-nucleate embryo sac. Hence, the correct sequence is one meiosis followed by three mitoses. Answer: (3) 1 Meiosis and 3 Mitosis.
Guessed Questions:
1. Which cell in the ovule directly undergoes meiosis to produce megaspores?
(1) Egg cell
(2) Megaspore mother cell
(3) Antipodal cell
(4) Synergid cell
Explanation: The megaspore mother cell (MMC) undergoes meiosis to form four haploid megaspores, only one of which develops into the female gametophyte. It is diploid before meiosis. Answer: (2) Megaspore mother cell.
2. In an angiosperm, how many nuclei are present in the mature female gametophyte?
(1) 4
(2) 6
(3) 8
(4) 16
Explanation: The functional megaspore undergoes three successive mitotic divisions to form an eight-nucleate embryo sac. These nuclei are organized into the egg apparatus, antipodal cells, and polar nuclei. Answer: (3) 8.
3. The central cell of the embryo sac is formed by the fusion of:
(1) Two synergids
(2) Two antipodals
(3) Two polar nuclei
(4) One egg and one synergid
Explanation: The two polar nuclei located in the central cell fuse to form a diploid secondary nucleus, which after fertilization forms the triploid endosperm. Answer: (3) Two polar nuclei.
4. Which of the following is the correct sequence in embryo sac development?
(1) MMC → Megaspores → Functional megaspore → Embryo sac
(2) MMC → Embryo sac → Megaspores
(3) MMC → Pollen → Megaspore
(4) Megaspore → MMC → Embryo sac
Explanation: Megasporogenesis starts from the diploid MMC producing haploid megaspores through meiosis. The functional megaspore then undergoes mitotic divisions to develop into the embryo sac. Answer: (1) MMC → Megaspores → Functional megaspore → Embryo sac.
5. The number of mitotic divisions involved in the formation of the mature embryo sac from the functional megaspore is:
(1) One
(2) Two
(3) Three
(4) Four
Explanation: The functional megaspore divides mitotically three times to produce an eight-nucleate embryo sac. These nuclei later organize into seven cells of the embryo sac. Answer: (3) Three.
6. In Polygonum type of embryo sac, how many antipodal cells are formed?
(1) Two
(2) Three
(3) Four
(4) Five
Explanation: In the Polygonum type, the embryo sac consists of three antipodal cells situated at the chalazal end, aiding in nutrition. Answer: (2) Three.
Assertion–Reason Type Question:
Assertion (A): The embryo sac is haploid.
Reason (R): It develops from a haploid functional megaspore formed after meiosis.
(1) Both A and R are true and R is the correct explanation of A
(2) Both A and R are true but R is not the correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Explanation: The embryo sac originates from a haploid functional megaspore, hence it remains haploid. R correctly explains A. Answer: (1) Both A and R are true and R is the correct explanation of A.
Matching Type Question:
Match the following:
List I – Structure | List II – Function
A. Egg cell | (i) Nutrition
B. Synergids | (ii) Attract pollen tube
C. Antipodals | (iii) Fertilization
D. Polar nuclei | (iv) Endosperm formation
(1) A–iii, B–ii, C–i, D–iv
(2) A–ii, B–i, C–iii, D–iv
(3) A–iv, B–iii, C–ii, D–i
(4) A–i, B–iv, C–ii, D–iii
Explanation: The egg cell participates in fertilization, synergids attract the pollen tube, antipodals provide nutrition, and polar nuclei form endosperm after fusion. Answer: (1) A–iii, B–ii, C–i, D–iv.
Fill in the Blanks:
The functional megaspore is always located towards the ________ end of the nucellus.
(1) Micropylar
(2) Chalazal
(3) Middle
(4) Funicular
Explanation: In most angiosperms, such as Polygonum type, the functional megaspore is positioned towards the chalazal end of the nucellus and develops into the embryo sac. Answer: (2) Chalazal.
Choose the Correct Statements:
Statement I: The embryo sac is formed from the megaspore mother cell by mitosis.
Statement II: The functional megaspore undergoes mitosis to form the embryo sac.
(1) Both statements are true
(2) Only Statement I is true
(3) Only Statement II is true
(4) Both statements are false
Explanation: The MMC undergoes meiosis first to form megaspores, and the functional megaspore then undergoes mitosis to form the embryo sac. Therefore, only Statement II is correct. Answer: (3) Only Statement II is true.
Topic: Microsporogenesis and Male Gametophyte; Subtopic: Tapetum and its Functions
Keyword Definitions:
• Tapetum: The innermost nutritive layer of the anther wall that provides nourishment to developing microspores.
• Microspore Mother Cell (MMC): Diploid cell that undergoes meiosis to form haploid microspores.
• Binucleate Cell: A cell possessing two nuclei, enhancing metabolic activity.
• Cytoplasm: Semi-fluid content of the cell where biochemical reactions occur.
• Microsporogenesis: Process of formation of microspores (pollen grains) from microspore mother cells.
Lead Question – 2025
Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Cells of the tapetum possess dense cytoplasm and generally have more than one nucleus.
Reason (R): Presence of more than one nucleus in the tapetum increases the efficiency of nourishing the developing microspore mother cells.
In light of the above statements, choose the most appropriate answer from the options given below:
(1) Both A and R are true and R is the correct explanation of A
(2) Both A and R are true but R is NOT the correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Explanation:
Tapetum cells have dense cytoplasm and are often binucleate or multinucleate. These characteristics increase their metabolic capacity, enabling efficient secretion of enzymes and nutrients essential for developing pollen grains. Therefore, both Assertion and Reason are true, and Reason correctly explains Assertion. Hence, the correct answer is (1).
Guessed Questions:
1. Tapetum is derived from which layer of the anther wall?
(1) Endothecium (2) Epidermis (3) Middle layers (4) Secondary parietal cells
Explanation: Tapetum originates from the innermost layer of the secondary parietal cells of the anther wall. It surrounds the microsporangium and nourishes developing pollen. Hence, the correct answer is Secondary parietal cells.
2. The tapetal cells are characterized by:
(1) Active mitosis (2) High metabolic activity (3) Presence of chloroplasts (4) Thick cell walls
Explanation: Tapetal cells show high metabolic activity, dense cytoplasm, and often two nuclei. They secrete materials for pollen wall formation, like sporopollenin precursors. Hence, the correct answer is High metabolic activity.
3. The function of the tapetum is to:
(1) Provide protection to pollen grains
(2) Help in meiosis of MMC
(3) Nourish developing microspores
(4) Form exine of the pollen wall
Explanation: Tapetum secretes nutrients, proteins, and sporopollenin precursors necessary for pollen wall formation and nourishment of microspores. Its secretory role is vital for pollen development. Hence, the correct answer is Nourish developing microspores.
4. Which of the following substances is secreted by the tapetum for pollen wall formation?
(1) Sporopollenin (2) Cutin (3) Suberin (4) Lignin
Explanation: The tapetum secretes sporopollenin precursors that harden the pollen exine, making it resistant to biological and chemical degradation. Hence, the correct answer is Sporopollenin.
5. During microsporogenesis, meiosis occurs in:
(1) Pollen mother cells (2) Tapetal cells (3) Endothecium (4) Pollen grains
Explanation: Microspore mother cells (pollen mother cells) undergo meiosis to form haploid microspores that mature into pollen grains. Hence, the correct answer is Pollen mother cells.
6. Which type of tapetum provides enzymes and nutrients for pollen development?
(1) Secretory (2) Amoeboid (3) Parietal (4) Parenchymatous
Explanation: The secretory or glandular type of tapetum releases enzymes and nutrients into the locule to nourish developing microspores. Hence, the correct answer is Secretory.
7. (Matching Type)
Match the anther parts with their functions:
A. Endothecium — (i) Protects the pollen sac
B. Tapetum — (ii) Provides nourishment to microspores
C. Epidermis — (iii) Helps in dehiscence
D. Middle layers — (iv) Degenerate after maturity
Options:
(1) A-iii, B-ii, C-i, D-iv
(2) A-ii, B-i, C-iv, D-iii
(3) A-i, B-ii, C-iii, D-iv
(4) A-iv, B-iii, C-i, D-ii
Explanation: Endothecium assists in anther dehiscence, tapetum nourishes microspores, epidermis protects pollen sac, and middle layers degenerate. Hence, the correct answer is (1).
8. (Fill in the Blanks)
The pollen wall is composed of an inner layer called ______ and an outer layer called ______.
(1) Exine, Intine (2) Intine, Exine (3) Sporopollenin, Cellulose (4) Cutin, Sporopollenin
Explanation: The pollen wall has two layers — outer tough exine made of sporopollenin and inner thin intine composed of pectin and cellulose. Hence, the correct answer is Exine, Intine.
9. (Choose the Correct Statements)
Statement I: Tapetum is essential for pollen maturation.
Statement II: Tapetal cells remain functional after pollen release.
(1) Both statements are true
(2) Both statements are false
(3) Only Statement I is true
(4) Only Statement II is true
Explanation: Tapetal cells are essential during microspore development but degenerate before pollen release. Hence, only Statement I is true. Correct answer: (3).
10. (Assertion–Reason Type)
Assertion (A): Tapetum is multinucleate and highly active.
Reason (R): It provides sporopollenin precursors to form the exine layer.
(1) Both A and R are true and R is the correct explanation of A
(2) Both A and R are true but R is not the correct explanation
(3) A is true, R is false
(4) A is false, R is true
Explanation: The multinucleate tapetum’s high metabolic activity supports secretion of sporopollenin precursors essential for pollen wall formation. Both A and R are true and R explains A correctly. Correct answer: (1).
Subtopic: Structure and Types of Seeds
Keyword Definitions:
• Scutellum: A single cotyledon found in monocot seeds like maize, functioning as an absorptive organ.
• Non-albuminous seed: Seeds that completely consume the endosperm during development, e.g., groundnut.
• Epiblast: A small rudimentary structure opposite the scutellum in monocot embryos.
• Perisperm: The persistent nucellus in some seeds that stores food material, e.g., black pepper.
Lead Question – 2025
Match List I with List II:
List-I List-II
A. Scutellum I. Persistent nucellus
B. Non-albuminous II. Cotyledon of monocot seed
C. Epiblast III. Groundnut
D. Perisperm IV. Rudimentary cotyledon
Choose the option with all correct matches.
(1) A-II, B-III, C-IV, D-I
(2) A-IV, B-III, C-II, D-I
(3) A-IV, B-III, C-I, D-II
(4) A-II, B-IV, C-III, D-I
Explanation:
The correct answer is (1) A-II, B-III, C-IV, D-I. Scutellum represents the single cotyledon in monocots aiding nutrient absorption. Non-albuminous seeds like groundnut consume all endosperm. Epiblast acts as a rudimentary cotyledon in monocot seeds. Perisperm, derived from the nucellus, remains as a storage tissue in some mature seeds. Each structure shows specialized adaptation for seed nourishment and development.
Guessed Questions:
1. The scutellum in a maize grain represents:
(1) Endosperm
(2) Cotyledon
(3) Perisperm
(4) Aleurone layer
Explanation: Scutellum is a modified cotyledon found in monocots like maize that absorbs nutrients from the endosperm during germination. It acts as a specialized transfer tissue, helping the growing embryo utilize stored food efficiently. Hence, the correct answer is (2) Cotyledon.
2. Groundnut is an example of which type of seed?
(1) Albuminous seed
(2) Non-albuminous seed
(3) Perispermic seed
(4) Monocot seed
Explanation: Groundnut is a dicot non-albuminous seed. During development, the endosperm is completely consumed by the embryo. Hence, the cotyledons act as food storage organs, rich in oil and protein. Thus, the correct answer is (2) Non-albuminous seed.
3. The perisperm in a seed originates from:
(1) Nucellus
(2) Endosperm
(3) Integuments
(4) Chalaza
Explanation: Perisperm is the persistent nucellus in the mature seed. It remains as a nutritive tissue outside the embryo sac and is seen in plants like black pepper and beet. Hence, the correct answer is (1) Nucellus.
4. Epiblast is found in:
(1) Monocot embryo
(2) Dicot embryo
(3) Gymnosperm embryo
(4) None of these
Explanation: Epiblast is a small, rudimentary outgrowth present opposite to the scutellum in monocot embryos. It has no functional significance but represents a vestigial structure. Hence, the correct answer is (1) Monocot embryo.
5. In which of the following seeds is perisperm present?
(1) Wheat
(2) Castor
(3) Black pepper
(4) Maize
Explanation: Black pepper and coffee seeds possess perisperm, a tissue derived from the persistent nucellus. It serves as a nutritive storage tissue. Hence, the correct answer is (3) Black pepper.
6. Albuminous seeds retain:
(1) Endosperm
(2) Perisperm
(3) Both endosperm and perisperm
(4) No storage tissue
Explanation: Albuminous seeds like maize and castor retain part of the endosperm as a storage tissue even after maturation. This endosperm nourishes the embryo during germination. Hence, the correct answer is (1) Endosperm.
Assertion-Reason Type:
Assertion (A): Non-albuminous seeds lack endosperm.
Reason (R): The endosperm is completely consumed during embryo development.
(1) Both A and R are true, and R is the correct explanation of A
(2) Both A and R are true, but R is not the correct explanation of A
(3) A is true, but R is false
(4) A is false, but R is true
Explanation: The correct answer is (1). Non-albuminous seeds like pea and groundnut utilize the entire endosperm during development. The food is stored in the cotyledons. Hence, both statements are true, and R correctly explains A.
Fill in the Blanks:
The persistent nucellus in some seeds is known as _______.
(1) Endosperm
(2) Perisperm
(3) Pericarp
(4) Cotyledon
Explanation: The persistent nucellus forms the perisperm, a nutritive tissue that remains outside the embryo sac. It is not formed from fertilization but remains from maternal tissue. Hence, the correct answer is (2) Perisperm.
Choose the Correct Statements:
Statement I: Groundnut seed contains perisperm.
Statement II: Scutellum acts as an absorptive organ in monocot seeds.
(1) Both statements are true
(2) Both statements are false
(3) Only Statement I is true
(4) Only Statement II is true
Explanation: The correct answer is (4). Groundnut is non-albuminous and lacks perisperm. Scutellum in monocots absorbs nutrients from the endosperm and transfers them to the embryo. Thus, only Statement II is true.
Topic: Embryo Sac Formation; Subtopic: Structure of Mature Embryo Sac
Keyword Definitions:
Embryo sac: The female gametophyte of flowering plants, typically consisting of seven cells and eight nuclei formed through megagametogenesis.
Megasporogenesis: Formation of haploid megaspores from diploid megaspore mother cell by meiosis in the ovule.
Megagametogenesis: Development of one functional megaspore into the mature embryo sac containing egg apparatus, polar nuclei, and antipodals.
Polar nuclei: Two haploid nuclei that fuse to form a diploid secondary nucleus during double fertilization.
Egg apparatus: A group of three cells at the micropylar end consisting of one egg cell and two synergids.
Lead Question – 2025
Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A): A typical unfertilised angiosperm embryo sac at maturity is 8-nucleate and 7-celled.
Reason (R): The egg apparatus has 2 polar nuclei.
(1) Both A and R are true and R is the correct explanation of A
(2) Both A and R are true but R is NOT the correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Explanation: The correct answer is (3) A is true but R is false. A mature angiosperm embryo sac is indeed 8-nucleate and 7-celled, consisting of an egg apparatus (one egg cell and two synergids), three antipodal cells, and two polar nuclei. However, the egg apparatus does not contain polar nuclei; they are located centrally, forming the secondary nucleus during double fertilization.
Guessed Questions:
1. How many nuclei and cells are present in a typical mature embryo sac of angiosperms?
(1) 7 cells and 8 nuclei
(2) 8 cells and 7 nuclei
(3) 6 cells and 6 nuclei
(4) 8 cells and 9 nuclei
Explanation: The mature embryo sac of an angiosperm contains 7 cells and 8 nuclei. It includes one egg cell, two synergids, three antipodals, and two polar nuclei which fuse to form the secondary nucleus before fertilization. This is the result of three mitotic divisions of the functional megaspore during megagametogenesis.
2. Which of the following correctly represents the arrangement of nuclei in a mature embryo sac?
(1) 3 antipodals at micropylar end
(2) 2 polar nuclei at micropylar end
(3) 3 antipodals at chalazal end
(4) 2 synergids at chalazal end
Explanation: The correct arrangement includes 3 antipodal cells at the chalazal end, an egg apparatus (1 egg cell and 2 synergids) at the micropylar end, and 2 polar nuclei in the central cell. This configuration ensures proper double fertilization and endosperm formation following pollen tube entry.
3. The fusion of one male gamete with the two polar nuclei forms:
(1) Zygote
(2) Primary endosperm nucleus
(3) Secondary nucleus
(4) Synergid
Explanation: The fusion of one male gamete with two polar nuclei forms the primary endosperm nucleus, a triploid structure that later develops into endosperm. This process, known as triple fusion, occurs simultaneously with fertilization of the egg cell, completing the double fertilization unique to angiosperms.
4. The functional megaspore in angiosperms develops into:
(1) Embryo
(2) Endosperm
(3) Embryo sac
(4) Ovary
Explanation: The functional megaspore undergoes three mitotic divisions to form the mature female gametophyte or embryo sac. This development process is called megagametogenesis and results in an 8-nucleate, 7-celled structure ready for fertilization within the ovule of flowering plants.
5. How many mitotic divisions are involved in the formation of the embryo sac from the functional megaspore?
(1) One
(2) Two
(3) Three
(4) Four
Explanation: The functional megaspore undergoes three successive mitotic divisions during megagametogenesis, producing eight nuclei. These nuclei are arranged in a specific pattern within the embryo sac, resulting in a seven-celled mature structure that participates in double fertilization.
6. The antipodal cells of an embryo sac are located at which end?
(1) Micropylar end
(2) Chalazal end
(3) Middle region
(4) Anywhere in embryo sac
Explanation: Antipodal cells are found at the chalazal end of the embryo sac. They play a nutritive role and degenerate after fertilization. Their position is opposite to the egg apparatus, which is located at the micropylar end, facilitating proper gamete fusion during fertilization.
7. (Matching Type)
Match the parts of the embryo sac with their respective roles:
A. Egg cell — (i) Nutrient absorption
B. Synergids — (ii) Guide pollen tube
C. Polar nuclei — (iii) Form endosperm
D. Antipodals — (iv) Fuse with male gamete
(1) A-(iv), B-(ii), C-(iii), D-(i)
(2) A-(iii), B-(i), C-(ii), D-(iv)
(3) A-(ii), B-(iii), C-(i), D-(iv)
(4) A-(iv), B-(i), C-(ii), D-(iii)
Explanation: The correct match is A-(iv), B-(ii), C-(iii), D-(i). The egg cell fuses with a male gamete to form the zygote, synergids guide the pollen tube, polar nuclei fuse with a sperm to form endosperm, and antipodals assist in nutrient absorption from the nucellus before degeneration.
8. (Fill in the Blanks)
The cell that directly gives rise to the embryo sac is the ________.
(1) Megaspore mother cell
(2) Secondary nucleus
(3) Egg cell
(4) Synergid
Explanation: The megaspore mother cell (MMC) undergoes meiosis to form four haploid megaspores, of which only one becomes functional and develops into the mature embryo sac. This sequence ensures proper haploid gametophyte formation for fertilization in angiosperms.
9. (Choose the Correct Statements)
Statement I: The embryo sac is formed from a functional megaspore.
Statement II: The embryo sac of angiosperms is diploid.
(1) Both statements are correct.
(2) Both statements are wrong.
(3) Only Statement I is correct.
(4) Only Statement II is correct.
Explanation: Only Statement I is correct. The embryo sac arises from a functional haploid megaspore through mitotic divisions. It is haploid, not diploid, because it forms from a meiotic product of the megaspore mother cell, maintaining the gametophytic generation’s ploidy.
10. (Single Correct)
Which structure in the embryo sac fuses with the male gamete to form the zygote?
(1) Egg cell
(2) Polar nuclei
(3) Synergid
(4) Antipodal cell
Explanation: The egg cell fuses with one of the two male gametes delivered by the pollen tube, forming the diploid zygote. The second male gamete fuses with the two polar nuclei, forming the triploid primary endosperm nucleus in a process called double fertilization, unique to angiosperms.
Topic: Seed and Fruit Subtopic: Structure of Monocot and Dicot Seeds
Keyword Definitions:
• Endosperm: Nutritive tissue that nourishes the developing embryo in a seed.
• Aleurone layer: Protein-rich outermost layer of the endosperm in cereal grains.
• Embryo: The young plant developing inside a seed formed after fertilization.
• Scutellum: A single cotyledon in monocot seeds that absorbs food from endosperm.
• Coleoptile: Protective sheath covering the emerging plumule in monocot seeds.
Lead Question (2025)
In the seeds of cereals, the outer covering of endosperm separates the embryo by a protein-rich layer called:
(1) Coleoptile
(2) Coleorhiza
(3) Integument
(4) Aleurone layer
Explanation:
In cereal grains like wheat and maize, the endosperm stores food for germination. The outermost layer of the endosperm is the aleurone layer, rich in proteins and enzymes. It separates the endosperm from the embryo and secretes hydrolytic enzymes during germination, converting stored starch into sugars for the growing embryo.
Answer: (4) Aleurone layer.
1. In maize seed, which part is responsible for absorption of nutrients from the endosperm during germination?
(1) Scutellum
(2) Aleurone layer
(3) Coleoptile
(4) Plumule
Explanation:
The scutellum in monocot seeds such as maize acts as the single cotyledon. It absorbs nutrients from the endosperm and transfers them to the developing embryo during germination. The aleurone layer only releases enzymes; actual nutrient absorption is done by the scutellum.
Answer: (1) Scutellum.
2. Which part of a monocot seed encloses the radicle and protects it during germination?
(1) Coleoptile
(2) Coleorhiza
(3) Scutellum
(4) Plumule
Explanation:
The coleorhiza is a protective sheath covering the radicle in monocot seeds. It facilitates the emergence of the root through the soil while protecting delicate tissues. The coleoptile, on the other hand, protects the plumule (shoot apex).
Answer: (2) Coleorhiza.
3. Which of the following statements about endosperm is correct?
(1) It is always haploid.
(2) It is formed before fertilization.
(3) It is triploid in most angiosperms.
(4) It does not store food.
Explanation:
In angiosperms, the endosperm is formed after double fertilization when one male gamete fuses with two polar nuclei, resulting in a triploid (3n) structure. It serves as a nutritive tissue for the developing embryo. Hence, it is triploid in most flowering plants.
Answer: (3) It is triploid in most angiosperms.
4. Assertion (A): The aleurone layer plays an important role in seed germination.
Reason (R): It secretes enzymes that hydrolyze stored food materials in the endosperm.
(1) Both A and R are true and R is the correct explanation of A
(2) Both A and R are true but R is not the correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Explanation:
The aleurone layer contains proteins and enzymes essential for germination. It releases amylase and protease in response to gibberellins from the embryo, converting starch and proteins of the endosperm into soluble nutrients. Hence both statements are true and R correctly explains A.
Answer: (1) Both A and R are true and R is the correct explanation of A.
5. Match the following:
List I (Structure) – List II (Function)
A. Scutellum – (i) Enzyme secretion
B. Coleoptile – (ii) Protects radicle
C. Aleurone layer – (iii) Absorbs nutrients
D. Coleorhiza – (iv) Protects plumule
(1) A–iii, B–iv, C–i, D–ii
(2) A–iv, B–iii, C–ii, D–i
(3) A–i, B–ii, C–iii, D–iv
(4) A–ii, B–i, C–iv, D–iii
Explanation:
The scutellum absorbs nutrients, coleoptile protects the plumule, aleurone layer secretes enzymes for digestion, and coleorhiza protects the radicle. Each structure supports seed germination by coordinating protection and nourishment of the embryo.
Answer: (1) A–iii, B–iv, C–i, D–ii.
6. The process of double fertilization in angiosperms results in formation of—
(1) Embryo and integument
(2) Endosperm and pericarp
(3) Embryo and endosperm
(4) Cotyledons and hilum
Explanation:
In double fertilization, one male gamete fuses with the egg to form the zygote (embryo), while the other fuses with two polar nuclei to form the triploid endosperm. This unique process is characteristic of flowering plants and ensures both embryo and endosperm development simultaneously.
Answer: (3) Embryo and endosperm.
7. In cereal seeds, food materials like starch and proteins are stored in which part?
(1) Cotyledon
(2) Aleurone layer
(3) Endosperm
(4) Pericarp
Explanation:
Cereal seeds like wheat and maize store large amounts of starch and proteins in the endosperm. The aleurone layer covers the endosperm but mainly functions enzymatically, not for food storage. Thus, the main storage tissue of cereals is the endosperm.
Answer: (3) Endosperm.
8. Fill in the Blank:
During seed germination in cereals, the enzyme α-amylase is secreted by the __________ layer.
(1) Scutellum
(2) Aleurone
(3) Endosperm
(4) Plumule
Explanation:
During germination, gibberellins released by the embryo stimulate the aleurone layer to secrete α-amylase, which hydrolyzes starch into sugars used by the embryo. This conversion provides instant energy for early growth and establishment of the seedling.
Answer: (2) Aleurone.
9. Choose the correct statements (Statement I & Statement II):
Statement I: Aleurone layer is a living tissue of the endosperm.
Statement II: It stores starch as reserve food material.
(1) Both statements are correct
(2) Both statements are incorrect
(3) Statement I is correct, Statement II is incorrect
(4) Statement I is incorrect, Statement II is correct
Explanation:
The aleurone layer is a living layer of protein-rich cells surrounding the endosperm. It stores proteins but not starch. Its primary function is to secrete enzymes during germination. Therefore, only Statement I is correct, and Statement II is incorrect.
Answer: (3) Statement I is correct, Statement II is incorrect.
10. The outermost covering of a maize grain is formed by—
(1) Testa and pericarp fused together
(2) Endosperm
(3) Integument only
(4) Aleurone layer
Explanation:
In maize grain, the fruit wall (pericarp) and seed coat (testa) are fused to form a single protective covering called the seed coat. This feature distinguishes caryopsis fruits like cereals, where the ovary wall and seed coat unite tightly.
Answer: (1) Testa and pericarp fused together.
Topic: Floral Formula and Floral Symbols; Subtopic: Symmetry and Ovary Position in Flowers
Keyword Definitions:
• Floral Formula: A symbolic representation of flower structure showing its symmetry, sexuality, and floral whorls.
• Zygomorphic: A flower that can be divided into two equal halves only in one vertical plane.
• Actinomorphic: A flower that can be divided into two equal halves in any radial plane.
• Inferior Ovary: Ovary positioned below other floral parts.
• Superior Ovary: Ovary positioned above other floral parts.
Lead Question – (2025)
Given below are two statements :
Statement I: In a floral formula, ⊕ stands for zygomorphic nature of the flower, and G stands for inferior ovary.
Statement II: In a floral formula, ⚥ stands for actinomorphic nature of the flower, and G stands for superior ovary.
In the light of the above statements, choose the correct answer from the options given below:
(1) Both Statement I and Statement II are correct
(2) Both Statement I and Statement II are incorrect
(3) Statement I is correct but Statement II is incorrect
(4) Statement I is incorrect but Statement II is correct
Explanation:
In floral formulas, the symbol (⊕) represents actinomorphic flowers, not zygomorphic ones. Zygomorphic flowers are denoted by (%). The ovary position is represented by G̅ for inferior ovary and G for superior ovary. Therefore, Statement I is incorrect, while Statement II correctly identifies the symbols. Hence, the correct answer is (4) Statement I is incorrect but Statement II is correct.
1. Which symbol in the floral formula denotes bisexuality?
(1) ⚥
(2) ⊕
(3) %
(4) G̅
Explanation:
The symbol ⚥ in a floral formula represents a bisexual flower, indicating the presence of both stamens and carpels. Such flowers can perform self-pollination and cross-pollination. Examples include Hibiscus and Mustard. Bisexuality enhances reproductive efficiency by allowing both male and female reproductive organs within the same flower.
2. Which of the following flowers is actinomorphic?
(1) Pea
(2) Cassia
(3) Datura
(4) Gulmohar
Explanation:
An actinomorphic flower can be divided into equal halves along any radial plane passing through its center. Datura is actinomorphic because of its radial symmetry, while pea and Cassia are zygomorphic. Radial symmetry promotes pollination by multiple pollinators, making actinomorphic flowers ecologically advantageous.
3. The ovary is called inferior when:
(1) It is above other floral parts
(2) It lies below other floral parts
(3) It is fused with the thalamus
(4) Both (2) and (3)
Explanation:
An ovary is inferior when it lies below the attachment of other floral whorls like petals and sepals. It is fused with the thalamus forming an epigynous flower, as in cucumber and guava. This structure protects the ovary during fertilization. Hence, the correct answer is (4) Both (2) and (3).
4. In a floral formula, what does % represent?
(1) Zygomorphic flower
(2) Actinomorphic flower
(3) Unisexual flower
(4) Epigynous flower
Explanation:
The % symbol in a floral formula denotes a zygomorphic flower, which can be divided into two equal halves in only one plane. Flowers like pea, Cassia, and Gulmohar are zygomorphic, helping in specific pollination mechanisms by restricting access to particular pollinators.
5. In which of the following conditions, the ovary is superior?
(1) Hypogynous flower
(2) Perigynous flower
(3) Epigynous flower
(4) None of these
Explanation:
In hypogynous flowers, the ovary is superior because it is placed above other floral whorls like petals, sepals, and stamens. Examples include Mustard and Hibiscus. Superior ovaries promote easy pollination and fertilization. Therefore, the correct answer is (1) Hypogynous flower.
6. Which of the following represents an epigynous flower?
(1) Mustard
(2) China rose
(3) Guava
(4) Brinjal
Explanation:
Epigynous flowers have an inferior ovary where other floral parts arise above it. Guava and cucumber show this feature, represented by G̅ in the floral formula. Such an arrangement protects the ovary from damage and external stress. Thus, the correct answer is (3) Guava.
7. Assertion – Reason Type Question
Assertion (A): Actinomorphic flowers promote cross-pollination.
Reason (R): Their radial symmetry allows access to pollinators from all directions.
(1) Both A and R are true, and R correctly explains A
(2) Both A and R are true, but R does not explain A
(3) A is true but R is false
(4) A is false but R is true
Explanation:
Actinomorphic flowers, like Datura, can be divided into equal halves in multiple planes. Their radial symmetry allows various pollinators to access nectar easily, thus encouraging cross-pollination. Both Assertion and Reason are true, and the Reason correctly explains the Assertion. Hence, the correct answer is (1).
8. Matching Type Question
Match the following symbols with their meanings:
List I
A. ⊕
B. %
C. ⚥
D. G̅
List II
1. Bisexual flower
2. Inferior ovary
3. Zygomorphic flower
4. Actinomorphic flower
Options:
(1) A-4, B-3, C-1, D-2
(2) A-3, B-4, C-1, D-2
(3) A-4, B-1, C-3, D-2
(4) A-2, B-4, C-1, D-3
Explanation:
In floral symbols: ⊕ denotes actinomorphic, % denotes zygomorphic, ⚥ represents bisexual, and G̅ indicates an inferior ovary. Understanding these symbols helps decode floral structures efficiently. Hence, the correct matching is (1) A-4, B-3, C-1, D-2.
9. Fill in the Blanks
In the floral formula of Mustard, the ovary is represented as ______.
(1) G
(2) G̅
(3) ⚥
(4) %
Explanation:
In Mustard (Brassica campestris), the ovary is superior and is represented by G in the floral formula. It indicates a hypogynous flower where the ovary lies above other whorls. Therefore, the correct answer is (1) G.
10. Choose the Correct Statements
Statement I: Zygomorphic flowers are radially symmetrical.
Statement II: Actinomorphic flowers are bilaterally symmetrical.
(1) Both statements are correct
(2) Both statements are incorrect
(3) Statement I is correct but Statement II is incorrect
(4) Statement I is incorrect but Statement II is correct
Explanation:
Zygomorphic flowers show bilateral symmetry, while actinomorphic flowers show radial symmetry. Hence, both statements are incorrect. Examples: Pea (zygomorphic), Datura (actinomorphic). Correct answer is (2).
Topic: Pollination; Subtopic: Types and Features of Wind and Water Pollination
Keyword Definitions:
• Pollination: Transfer of pollen grains from anther to stigma for fertilization.
• Anemophily: Pollination by wind, common in grasses and cereals.
• Hydrophily: Pollination by water, found in aquatic plants like Vallisneria.
• Nectar: A sugary fluid secreted by flowers to attract pollinators.
• Pollen grains: Male gametophytes produced in anthers that fertilize ovules.
• Flowers: Reproductive structures in angiosperms specialized for pollination and fertilization.
Lead Question – 2025
Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Both wind and water pollinated flowers are not very colourful and do not produce nectar.
Reason (R): The flowers produce enormous amount of pollen grains in wind and water pollinated flowers.
In the light of the above statements, choose the correct answer from the options given below:
(1) Both A and R are true and R is the correct explanation of A
(2) Both A and R are true but R is NOT the correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Explanation:
Wind and water pollinated flowers rely on abiotic agents; hence, they are usually dull, small, and nectarless as they do not need to attract insects. They produce a large number of lightweight pollen grains to ensure successful pollination. Thus, both A and R are true, and R correctly explains A. The correct answer is (1).
Guessed Questions:
1. Single Correct Answer:
Which of the following plants shows hydrophilous pollination?
(1) Maize
(2) Vallisneria
(3) Wheat
(4) Hibiscus
Explanation:
Hydrophily refers to pollination by water, observed in aquatic plants like Vallisneria. Male flowers are released on the water surface and carried to female flowers. This process ensures fertilization without animal aid. The correct answer is (2) Vallisneria.
2. Single Correct Answer:
In wind-pollinated flowers, the pollen grains are:
(1) Heavy and sticky
(2) Light and non-sticky
(3) Large and spiny
(4) Moist and oily
Explanation:
Wind-pollinated flowers (anemophilous) produce light, non-sticky pollen grains that can easily be carried by air currents. They are produced in large numbers to compensate for wastage. Hence, the correct answer is (2) Light and non-sticky.
3. Single Correct Answer:
Which of the following is an adaptation for anemophily?
(1) Brightly coloured petals
(2) Fragrant flowers
(3) Exposed stamens and feathery stigma
(4) Nectar secretion
Explanation:
Wind-pollinated flowers such as maize and grasses have exposed stamens for pollen dispersal and feathery stigmas to trap airborne pollen effectively. They lack bright petals or nectar. Hence, the correct answer is (3) Exposed stamens and feathery stigma.
4. Single Correct Answer:
Hydrophilous pollination is commonly observed in:
(1) Rice and maize
(2) Vallisneria and Hydrilla
(3) Rose and sunflower
(4) Mango and guava
Explanation:
Hydrophily occurs in aquatic plants like Vallisneria and Hydrilla. These species utilize water currents for pollen transfer. Terrestrial plants like rose and sunflower rely on biotic pollination. Hence, the correct answer is (2) Vallisneria and Hydrilla.
5. Single Correct Answer:
Why do wind-pollinated flowers produce large amounts of pollen?
(1) To attract pollinators
(2) To compensate for loss during transfer
(3) To increase flower colouration
(4) To enhance nectar secretion
Explanation:
Wind-pollinated flowers produce vast quantities of pollen because most are lost during dispersal. Since they depend on air movement, only a fraction reaches the female stigma. The correct answer is (2) To compensate for loss during transfer.
6. Single Correct Answer:
In which type of pollination are flowers usually large, colourful, and scented?
(1) Anemophily
(2) Hydrophily
(3) Entomophily
(4) Zoophily
Explanation:
Entomophilous flowers depend on insects for pollination. To attract them, these flowers are large, brightly coloured, and secrete nectar and fragrance. Examples include rose and sunflower. Hence, the correct answer is (3) Entomophily.
7. Assertion–Reason Type:
Assertion (A): Hydrophilous plants produce sticky pollen grains.
Reason (R): Sticky pollen grains help them float on the water surface.
(1) Both A and R are true, and R is the correct explanation of A
(2) Both A and R are true, but R is not the correct explanation of A
(3) A is false, R is true
(4) A is true, R is false
Explanation:
Hydrophilous plants produce smooth, non-sticky pollen to enable floating in water. Sticky pollen would sink, reducing fertilization chances. Hence, A is false and R is true. The correct answer is (3).
8. Matching Type:
Match the following types of pollination with their examples:
A. Anemophily – (i) Vallisneria
B. Hydrophily – (ii) Maize
C. Entomophily – (iii) Hibiscus
D. Ornithophily – (iv) Butea
(1) A-ii, B-i, C-iii, D-iv
(2) A-i, B-ii, C-iv, D-iii
(3) A-iii, B-iv, C-i, D-ii
(4) A-ii, B-iii, C-iv, D-i
Explanation:
Anemophily (wind pollination) occurs in maize, Hydrophily (water pollination) in Vallisneria, Entomophily (insect pollination) in Hibiscus, and Ornithophily (bird pollination) in Butea. Thus, the correct answer is (1) A-ii, B-i, C-iii, D-iv.
9. Fill in the Blanks:
In wind-pollinated flowers, the stigma is usually __________.
(1) Sticky
(2) Feathery
(3) Small
(4) Enclosed
Explanation:
To effectively trap airborne pollen, wind-pollinated flowers have large, feathery stigmas that increase the surface area. They are non-sticky but efficient in pollen collection. The correct answer is (2) Feathery.
10. Choose the Correct Statements:
Statement I: Wind-pollinated flowers are large and colourful.
Statement II: Hydrophilous flowers depend on water for pollen transfer.
(1) Both statements are correct
(2) Both statements are incorrect
(3) Statement I is correct, Statement II is incorrect
(4) Statement I is incorrect, Statement II is correct
Explanation:
Wind-pollinated flowers are usually small, dull, and lack nectar. Hydrophilous flowers, like Vallisneria, rely on water for pollination. Hence, Statement I is incorrect, while Statement II is correct. The correct answer is (4).
Topic: Floral Structures and Modifications; Subtopic: Stamens and Carpels – Fusion and Arrangement
Keyword Definitions:
Androecium: The male reproductive part of a flower consisting of stamens, each with a filament and an anther.
Polyadelphous: Condition where stamens are united by their filaments into more than two bundles, seen in Citrus species.
Syncarpous: A gynoecium in which two or more carpels are fused, forming a compound ovary as in Hibiscus.
Staminode: A sterile stamen that does not bear pollen but may be modified or rudimentary.
Epipetalous: Stamens attached to the petals, typical of plants like brinjal and tobacco.
Carpel: Female reproductive organ of a flower consisting of ovary, style, and stigma.
Monadelphous: Stamens united into one bundle by their filaments, common in China rose.
Diadelphous: Stamens united into two bundles, typical of pea family members.
Gynoecium: The female reproductive whorl of a flower composed of carpels.
Filament: The stalk of the stamen that supports the anther.
Lead Question – 2024 (Jhajjhar)
Match List-I with List-II.
List-I List-II
A. Polyadelphous I. Filaments of stamens united into more than two bundles
B. Syncarpous II. Sterile stamen
C. Staminode III. Stamens are attached to the petals
D. Epipetalous IV. Carpels are fused
1. A-I, B-IV, C-II, D-III
2. A-II, B-I, C-III, D-IV
3. A-II, B-III, C-I, D-IV
4. A-I, B-II, C-IV, D-III
Explanation: In polyadelphous condition, filaments are united into more than two bundles; syncarpous flowers have fused carpels; staminodes are sterile stamens; and epipetalous condition refers to stamens attached to petals. Thus, the correct match is A–I, B–IV, C–II, D–III. Hence, the correct answer is Option 1. These features aid in classification and floral evolution studies.
Guessed Questions:
1. In which of the following plants are stamens polyadelphous?
1. China rose
2. Citrus
3. Pea
4. Brinjal
Explanation: In Citrus species, stamens are united into more than two bundles forming the polyadelphous condition. This arrangement aids in the structural support of stamens and pollen distribution. Hence, the correct answer is Citrus.
2. Which of the following plants shows monadelphous condition of stamens?
1. Pea
2. Hibiscus
3. Citrus
4. Solanum
Explanation: In Hibiscus, all stamens are united by their filaments into a single bundle, forming the monadelphous condition. This is a characteristic feature of the Malvaceae family. Hence, the correct answer is Hibiscus.
3. In pea flower, stamens are arranged in which condition?
1. Monadelphous
2. Diadelphous
3. Polyadelphous
4. Syngenesious
Explanation: In pea, stamens are united by their filaments into two bundles — nine stamens in one bundle and one free — called diadelphous condition, typical of Fabaceae family. Hence, the correct answer is Diadelphous.
4. Assertion-Reason:
Assertion (A): In epipetalous flowers, stamens are attached to petals.
Reason (R): Epipetalous condition enhances pollen transfer by ensuring proximity to pollinators visiting petals.
1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, but R is true.
Explanation: Both A and R are true, and R correctly explains A. The epipetalous condition helps in effective pollination as stamens are positioned for contact with pollinators. Correct answer: Option 1.
5. Fill in the blank:
When carpels are fused, the gynoecium is called __________.
1. Apocarpous
2. Syncarpous
3. Polycarpous
4. Multicarpellary
Explanation: In a syncarpous gynoecium, the carpels are fused either partially or completely, forming a compound ovary. This condition occurs in flowers like tomato and Hibiscus. Therefore, the correct answer is Syncarpous.
6. Choose the correct statements:
Statement I: Staminodes are functional stamens.
Statement II: Syncarpous gynoecium has fused carpels.
1. Both statements are true.
2. Statement I true, Statement II false.
3. Statement I false, Statement II true.
4. Both statements are false.
Explanation: Staminodes are sterile stamens, not functional ones. Syncarpous condition represents fused carpels. Hence, Statement I is false, and Statement II is true. Correct answer: Option 3.
7. Which of the following plants exhibits epipetalous stamens?
1. Pea
2. Solanum
3. Citrus
4. Mustard
Explanation: In Solanum (brinjal), stamens are attached to petals, showing the epipetalous condition. It facilitates effective pollen transfer by pollinators. Hence, the correct answer is Solanum.
8. Match List-I with List-II:
List-I List-II
A. Monadelphous 1. Hibiscus
B. Diadelphous 2. Pea
C. Polyadelphous 3. Citrus
D. Epipetalous 4. Solanum
1. A-1, B-2, C-3, D-4
2. A-3, B-4, C-1, D-2
3. A-4, B-1, C-3, D-2
4. A-2, B-1, C-4, D-3
Explanation: Monadelphous–Hibiscus, Diadelphous–Pea, Polyadelphous–Citrus, and Epipetalous–Solanum. Hence, the correct answer is Option 1.
9. Which of the following describes the condition of fused filaments in more than two bundles?
1. Polyadelphous
2. Monadelphous
3. Diadelphous
4. Syngenesious
Explanation: In the polyadelphous condition, filaments of stamens are united into more than two bundles. This arrangement occurs in Citrus and is a characteristic feature of the Rutaceae family. Hence, the correct answer is Polyadelphous.
10. Which of the following represents an apocarpous gynoecium?
1. Lotus
2. Tomato
3. Hibiscus
4. Datura
Explanation: In an apocarpous gynoecium, carpels are free, as seen in lotus and rose. In contrast, tomato and Hibiscus have a syncarpous condition with fused carpels. Hence, the correct answer is Lotus.
Topic: Gametophyte Development; Subtopic: Female Gametophyte (Embryo Sac)
Keyword Definitions:
Gametophyte: The haploid generation of plants that produces gametes through mitosis.
Embryo Sac: The female gametophyte of flowering plants, formed from the functional megaspore.
Ovule: The structure in the ovary that develops into a seed after fertilization.
Nucellus: The central part of the ovule containing the embryo sac and nutritive tissues.
Endosperm: A triploid nutritive tissue formed after double fertilization in angiosperms.
Lead Question - 2024 (Jhajjar)
Which of the following represents the female gametophyte?
1. Ovule
2. Embryo sac
3. Nucellus
4. Endosperm
Explanation: The female gametophyte of flowering plants is the embryo sac, which develops from the functional megaspore through mitotic divisions. Typically, it contains seven cells and eight nuclei — one egg cell, two synergids, three antipodals, and two polar nuclei. The embryo sac remains embedded within the ovule and participates directly in fertilization.
Guessed Question 1:
The embryo sac develops from:
1. Microspore
2. Megaspore
3. Zygote
4. Endosperm
Explanation: The embryo sac, or female gametophyte, arises from the functional megaspore formed by meiosis of the megaspore mother cell inside the ovule. This megaspore undergoes three mitotic divisions to produce eight nuclei, forming the mature embryo sac. Thus, option 2 is correct.
Guessed Question 2:
In a typical angiosperm, the number of nuclei in a mature embryo sac is:
1. Four
2. Six
3. Eight
4. Ten
Explanation: The mature embryo sac of flowering plants contains eight haploid nuclei arranged in seven cells: one egg cell, two synergids, three antipodals, and a central cell with two polar nuclei. These nuclei play essential roles during fertilization and endosperm formation. Therefore, the correct answer is option 3 (Eight).
Guessed Question 3:
The functional megaspore that develops into an embryo sac is:
1. Haploid
2. Diploid
3. Triploid
4. Tetraploid
Explanation: The functional megaspore is a haploid cell formed through meiosis of the diploid megaspore mother cell. It undergoes mitotic divisions to produce the multicellular embryo sac. Hence, the female gametophyte remains haploid throughout its development, making option 1 correct.
Guessed Question 4:
The antipodal cells in an embryo sac are located at the:
1. Micropylar end
2. Chalazal end
3. Central region
4. Near egg apparatus
Explanation: The embryo sac has a distinct polarity. The egg apparatus, consisting of the egg cell and synergids, is present at the micropylar end, while three antipodal cells occupy the chalazal end. These antipodal cells are often nutritive in function. Therefore, option 2 is correct.
Guessed Question 5:
The central cell in the embryo sac becomes:
1. Zygote
2. Endosperm
3. Ovule wall
4. Embryo
Explanation: During double fertilization, one male gamete fuses with two polar nuclei of the central cell, forming a triploid primary endosperm nucleus, which develops into endosperm. This provides nutrition to the developing embryo. Hence, option 2 is correct — the central cell gives rise to endosperm.
Guessed Question 6:
The number of cells and nuclei in a mature embryo sac are respectively:
1. 7 and 8
2. 8 and 8
3. 7 and 7
4. 8 and 7
Explanation: A mature embryo sac typically has seven cells and eight nuclei — one egg cell, two synergids, three antipodal cells, and one central cell containing two polar nuclei. Thus, the configuration is described as 7 cells and 8 nuclei. Hence, option 1 is correct.
Assertion-Reason Question:
Assertion (A): The embryo sac is the female gametophyte in flowering plants.
Reason (R): It develops from the functional megaspore through meiosis.
1. Both A and R are true, and R is the correct explanation of A
2. Both A and R are true, but R is not the correct explanation of A
3. A is true, R is false
4. A is false, R is true
Explanation: The embryo sac represents the female gametophyte, but it develops from the functional megaspore through mitotic, not meiotic, divisions. Meiosis produces megaspores, of which only one survives. Hence, A is true, but R is false. Correct answer: option 3.
Matching Type Question:
Match the following:
A. Egg apparatus — (i) Two polar nuclei
B. Central cell — (ii) One egg + two synergids
C. Antipodals — (iii) Chalazal end
D. Nucellus — (iv) Nutritive tissue
1. A-ii, B-i, C-iii, D-iv
2. A-i, B-ii, C-iv, D-iii
3. A-iii, B-ii, C-i, D-iv
4. A-ii, B-iii, C-i, D-iv
Explanation: The egg apparatus (ii) consists of one egg and two synergids at the micropylar end; the central cell (i) has two polar nuclei; the antipodals (iii) are situated at the chalazal end; and the nucellus (iv) provides nourishment. Hence, the correct match is option 1.
Fill in the Blanks Question:
The female gametophyte in angiosperms is called _______.
1. Ovary
2. Embryo sac
3. Megaspore mother cell
4. Endosperm
Explanation: The female gametophyte in flowering plants is known as the embryo sac. It develops from the functional megaspore inside the ovule through mitotic divisions and contains all cells necessary for fertilization. Thus, option 2 is correct.
Choose the Correct Statements Question:
Statement I: Embryo sac is haploid.
Statement II: Endosperm is diploid.
1. Both statements are correct
2. Both statements are incorrect
3. Statement I is correct, Statement II is incorrect
4. Statement I is incorrect, Statement II is correct
Explanation: The embryo sac, derived from a haploid megaspore, is haploid, while the endosperm formed after double fertilization is triploid (3n), not diploid. Therefore, Statement I is correct, and Statement II is incorrect. Hence, option 3 is the right choice.
Topic: Structure of Ovule; Subtopic: Parts of the Ovule – Nucellus, Integument, Chalaza, and Hilum
Keyword Definitions:
• Ovule: The structure in the ovary of flowering plants that develops into a seed after fertilization.
• Funicle: The stalk that attaches the ovule to the placenta of the ovary.
• Hilum: The point of attachment between the ovule and the funicle.
• Integuments: Protective layers surrounding the nucellus of the ovule.
• Nucellus: The central tissue of the ovule containing the embryo sac.
• Chalaza: The basal region of the ovule opposite the micropyle, where integuments and nucellus merge.
Lead Question – 2024 (Jhajjhar)
The junction between ovule and funicle is represented by:
1. Nucellus
2. Integument
3. Chalaza
4. Hilum
Explanation: The hilum is the scar or junction between the ovule and the funicle, through which vascular strands pass nutrients from the placenta to the developing ovule. After fertilization and seed development, the hilum remains as a scar on the seed coat. Hence, the correct answer is option 4.
Guessed Questions:
1. Which part of the ovule provides nourishment to the developing embryo sac?
1. Integuments
2. Nucellus
3. Hilum
4. Micropyle
Explanation: The nucellus is the central mass of parenchymatous cells within the ovule that supplies nourishment to the developing embryo sac. It is analogous to the megasporangium of seed plants and persists as a nutritive tissue until fertilization occurs. Hence, the correct answer is option 2.
2. The micropyle of an ovule represents:
1. Point of attachment of funicle
2. Opening between integuments
3. Region opposite to chalaza
4. Both 2 and 3
Explanation: The micropyle is the minute opening at one end of the ovule formed by the incomplete fusion of integuments. It lies opposite the chalazal region and allows the entry of pollen tube for fertilization. Therefore, both statements 2 and 3 are correct. Correct answer: option 4.
3. In anatropous ovules, the micropyle lies:
1. Directly above the chalaza
2. Next to the funicle
3. In line with the nucellus
4. At right angles to the funicle
Explanation: In anatropous ovules, which are most common in angiosperms, the ovule becomes inverted during development, bringing the micropyle close to the funicle. This inverted position aids in efficient fertilization. Thus, the correct answer is option 2.
4. Which of the following is the correct sequence from the micropyle end to the chalazal end of an ovule?
1. Micropyle → Nucellus → Chalaza
2. Hilum → Chalaza → Micropyle
3. Micropyle → Embryo sac → Chalaza
4. Chalaza → Nucellus → Micropyle
Explanation: The ovule structure starts at the micropyle end, followed by the nucellus containing the embryo sac, and terminates at the chalazal region. The chalaza marks the base of the ovule where integuments and nucellus meet. Correct answer: option 3.
5. The ovule after fertilization develops into:
1. Fruit
2. Seed
3. Endosperm
4. Ovary
Explanation: After fertilization, the ovule transforms into a seed while the ovary develops into a fruit. The integuments of the ovule harden to form the seed coat, protecting the embryo within. Hence, the correct answer is option 2.
6. The funicle of the ovule is directly connected to the:
1. Hilum
2. Chalaza
3. Nucellus
4. Embryo sac
Explanation: The funicle serves as the stalk connecting the ovule to the placenta in the ovary. The point where it attaches to the ovule body is the hilum, which acts as a conduit for nutrient transport. Therefore, the correct answer is option 1.
Assertion–Reason Type Question
7. Assertion (A): The hilum is the junction between the ovule and the funicle.
Reason (R): The hilum connects the ovule to the nucellus for nutrient exchange.
1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, but R is true.
Explanation: The hilum indeed represents the point of attachment between the ovule and funicle, but it does not directly connect to the nucellus. Instead, it facilitates the vascular connection from placenta to ovule. Thus, A is true but R is false. Correct answer: option 3.
Matching Type Question
8. Match List I with List II:
List I – Part of Ovule
A. Nucellus
B. Integument
C. Chalaza
D. Hilum
List II – Description
I. Protective covering
II. Region opposite to micropyle
III. Central mass of cells
IV. Point of attachment to funicle
1. A-III, B-I, C-II, D-IV
2. A-I, B-II, C-IV, D-III
3. A-II, B-IV, C-I, D-III
4. A-IV, B-III, C-II, D-I
Explanation: The nucellus (III) is the nutritive tissue of the ovule, integument (I) forms its protective covering, chalaza (II) is the basal region opposite the micropyle, and hilum (IV) connects the ovule to the funicle. Thus, the correct matching is A-III, B-I, C-II, D-IV. Correct answer: option 1.
Fill in the Blanks Question
9. Fill in the blank: The basal region of the ovule where integuments and nucellus merge is called ________.
1. Micropyle
2. Chalaza
3. Hilum
4. Funicle
Explanation: The chalaza is the region at the base of the ovule opposite the micropyle, where the integuments and nucellus meet. It represents the vascular entry point for nutrients from the funicle. Hence, the correct answer is option 2.
Choose the Correct Statements
10. Statement I: In a mature ovule, the chalaza lies opposite to the micropyle.
Statement II: Hilum is the region where integuments merge with nucellus.
1. Both statements are correct.
2. Both statements are incorrect.
3. Only Statement I is correct.
4. Only Statement II is correct.
Explanation: The chalaza is indeed located opposite the micropyle and marks the base of the ovule. The hilum, however, is the junction between the ovule and the funicle, not the site of integument fusion. Thus, only Statement I is correct. Correct answer: option 3.
Topic: Flower and Inflorescence; Subtopic: Types of Flowers and Floral Structures
Keyword Definitions:
Inflorescence: The arrangement of flowers on the floral axis or peduncle of a plant.
Actinomorphic Flower: A flower that can be divided into equal halves along any vertical plane, showing radial symmetry.
Epigynous Flower: A flower in which the ovary is completely enclosed by the thalamus, with floral parts arising above the ovary.
Bract: A reduced leaf-like structure found at the base of the flower or inflorescence.
Hypogynous Flower: A flower in which the ovary is superior and other floral parts arise below it.
Lead Question – 2024 (Jhajjar)
Read the following statements and choose the set of correct statements:
A. In cymose inflorescence, the flowers are borne in an acropetalous succession.
B. In gulmohar, the flowers are actinomorphic.
C. In the flowers of cucumber, the margin of the thalamus grows upward enclosing the ovary completely and getting fused with it, the other parts of flowers arise above the ovary.
D. Bracts are reduced leaves found at the base of the pedicel.
E. The flowers are hypogynous in mustard.
Options:
1. A, B, C only
2. B, D, E only
3. A, C, D only
4. C, D, E only
Answer: B, D, E only.
Explanation: Gulmohar flowers are actinomorphic, bracts are reduced leaves at the base of the pedicel, and mustard flowers are hypogynous with a superior ovary. Cymose inflorescences are basipetalous, not acropetalous. Cucumber flowers are epigynous, not hypogynous. Hence, only statements B, D, and E are correct in this context of floral morphology.
1. Single Correct Answer Question:
In which type of inflorescence does the main axis terminate into a flower?
1. Racemose
2. Cymose
3. Compound raceme
4. Umbel
Answer: Cymose.
Explanation: In cymose inflorescence, the main axis ends in a flower, which is the first to bloom. Subsequent flowers arise from lateral branches in a basipetal or centrifugal sequence. This type of inflorescence exhibits determinate growth because the terminal flower ceases the elongation of the main axis after blooming.
2. Single Correct Answer Question:
Which of the following floral conditions shows an inferior ovary?
1. Hypogynous
2. Perigynous
3. Epigynous
4. Acyclic
Answer: Epigynous.
Explanation: In epigynous flowers, the ovary is completely enclosed by the fused thalamus, and other floral parts arise above it, making the ovary inferior. Examples include cucumber and guava. This arrangement helps protect the ovary during fertilization and is typical of advanced angiosperms with complex floral structures.
3. Single Correct Answer Question:
In mustard, the type of ovary is:
1. Inferior
2. Superior
3. Half-inferior
4. Marginal
Answer: Superior.
Explanation: Mustard flowers are hypogynous with a superior ovary, meaning the ovary sits above the attachment of other floral whorls. The thalamus is flat or slightly convex, and petals, sepals, and stamens arise below the ovary. This arrangement is common among primitive flowers like mustard and hibiscus species.
4. Single Correct Answer Question:
Flowers that can be divided into two equal halves in one vertical plane only are called:
1. Actinomorphic
2. Zygomorphic
3. Asymmetric
4. Radial
Answer: Zygomorphic.
Explanation: Zygomorphic flowers, such as those in pea and orchid, have bilateral symmetry and can be divided into equal halves by only one vertical plane. This adaptation ensures specialized pollination mechanisms by certain pollinators, promoting cross-pollination and increasing genetic diversity among flowering plant species.
5. Single Correct Answer Question:
Which of the following statements correctly defines bracts?
1. Colorful petals of flowers
2. Modified leaves at the base of pedicel
3. Floral appendages attached to sepals
4. Specialized glands secreting nectar
Answer: Modified leaves at the base of pedicel.
Explanation: Bracts are small, green or colored, leaf-like structures found at the base of a flower or inflorescence. They protect the developing flower buds and sometimes attract pollinators by resembling petals. Examples include bougainvillea, where bracts are brightly colored and serve to attract pollinators effectively.
6. Single Correct Answer Question:
In which of the following, the flowers are epigynous?
1. Mustard
2. China rose
3. Cucumber
4. Datura
Answer: Cucumber.
Explanation: Cucumber flowers are epigynous, having an inferior ovary completely enclosed by the fused thalamus. The other floral whorls—sepals, petals, and stamens—arise above the ovary. This floral arrangement aids in protection and supports the development of the fruit, which forms below the fused floral parts.
7. Assertion-Reason Question:
Assertion (A): In cymose inflorescence, the main axis terminates in a flower.
Reason (R): The growth of the main axis in cymose inflorescence is indeterminate.
Options:
1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, but R is true.
Answer: A is true, but R is false.
Explanation: In cymose inflorescence, the main axis ends in a flower, showing determinate growth because further elongation stops after the terminal flower forms. Therefore, the reason stating indeterminate growth is false. The correct explanation is that lateral branches continue growth basipetally after the main axis ceases.
8. Matching Type Question:
Match List I with List II:
A. Hypogynous flower – I. Superior ovary
B. Epigynous flower – II. Inferior ovary
C. Perigynous flower – III. Half-inferior ovary
D. Actinomorphic flower – IV. Radial symmetry
Options:
1. A-I, B-II, C-III, D-IV
2. A-II, B-I, C-III, D-IV
3. A-I, B-III, C-II, D-IV
4. A-III, B-II, C-I, D-IV
Answer: A-I, B-II, C-III, D-IV.
Explanation: Hypogynous flowers (e.g., mustard) have superior ovaries. Epigynous flowers (e.g., cucumber) possess inferior ovaries. Perigynous flowers (e.g., plum) have half-inferior ovaries. Actinomorphic flowers show radial symmetry and can be divided into equal halves along any vertical plane, ensuring effective pollination by various insects and animals.
9. Fill in the Blanks Question:
Flowers in which the ovary is completely enclosed by the thalamus are called __________ flowers.
1. Hypogynous
2. Perigynous
3. Epigynous
4. Zygomorphic
Answer: Epigynous.
Explanation: In epigynous flowers, the ovary is completely enclosed by the fused thalamus, and other floral parts arise above it, making the ovary inferior. This feature is seen in cucumber and guava flowers. It provides protection during fertilization and is a hallmark of advanced angiosperm floral evolution and fruit development.
10. Choose the Correct Statements (Statement I & II) Question:
Statement I: In hypogynous flowers, the ovary is superior.
Statement II: In epigynous flowers, the ovary is inferior.
1. Both statements are true.
2. Both statements are false.
3. Statement I is true but Statement II is false.
4. Statement I is false but Statement II is true.
Answer: Both statements are true.
Explanation: In hypogynous flowers, the ovary is superior as other whorls arise below it (e.g., mustard). In epigynous flowers, the ovary is inferior because the thalamus encloses it and other whorls arise above (e.g., cucumber). These structural differences influence floral development and reproductive adaptation across species.
Subtopic: Floral Characteristics and Aestivation
Keyword Definitions:
Aestivation: The arrangement of floral parts (especially petals and sepals) in a flower bud before it opens.
Perigynous flower: A flower where the ovary is situated in the center, and other floral parts are attached to the rim of the thalamus, e.g., rose.
Placentation: The arrangement of ovules inside the ovary.
Marginal placentation: Ovules are borne along the margin of a single-chambered ovary, as in pea.
Drupe: A fleshy fruit with a single seed enclosed in a hard endocarp, e.g., mango.
Twisted aestivation: Arrangement where one petal overlaps the next in a regular sequence, e.g., cotton.
Lead Question - 2024
Match List I with List II
List I List II
A. Rose I. Twisted aestivation
B. Pea II. Perigynous flower
C. Cotton III. Drupe
D. Mango IV. Marginal placentation
Choose the correct answer from the options given below:
(1) A–I, B–II, C–III, D–IV
(2) A–IV, B–III, C–II, D–I
(3) A–II, B–III, C–IV, D–I
(4) A–II, B–IV, C–I, D–III
Explanation: The correct answer is (4) A–II, B–IV, C–I, D–III. Rose is a perigynous flower as floral parts are attached around the ovary. Pea shows marginal placentation with ovules on the margin of a unilocular ovary. Cotton exhibits twisted aestivation in petals, and mango forms a drupe fruit with a single seed surrounded by a stony endocarp.
1. Which type of aestivation is seen in the petals of China rose?
(1) Valvate
(2) Twisted
(3) Imbricate
(4) Vexillary
Explanation: The answer is (2) Twisted. In China rose (Hibiscus), one petal overlaps the next in a regular sequence forming a twisted arrangement. This is a common pattern among members of the Malvaceae family, including cotton. Twisted aestivation helps in compact arrangement of petals in the bud stage, providing structural support and protection.
2. In which of the following flowers is the ovary half-inferior (perigynous)?
(1) Mustard
(2) Pea
(3) Rose
(4) Cucumber
Explanation: The answer is (3) Rose. A perigynous flower has a cup-shaped thalamus (hypanthium) with the ovary situated in the center, and other floral parts attached to its rim. The ovary is half-inferior in this arrangement. Rose and peach are typical examples. This feature distinguishes them from epigynous and hypogynous flowers.
3. Marginal placentation is found in which of the following plants?
(1) Mustard
(2) Sunflower
(3) Pea
(4) Datura
Explanation: The answer is (3) Pea. In marginal placentation, the ovules develop along the margin of the ovary in a single line. The ovary is monocarpellary and unilocular. This arrangement is characteristic of members of the family Fabaceae, such as pea, bean, and gram, providing efficient ovule arrangement along the margin of the ovary wall.
4. Which of the following correctly represents a drupe fruit?
(1) Tomato
(2) Mango
(3) Apple
(4) Orange
Explanation: The answer is (2) Mango. A drupe fruit develops from a monocarpellary superior ovary and contains one seed enclosed within a hard stony endocarp. The outer layers form a fleshy mesocarp and a thin epicarp. Mango and coconut are classic examples, where the pericarp is differentiated into distinct layers protecting the seed inside.
5. Which type of ovary is present in a hypogynous flower?
(1) Inferior ovary
(2) Half-inferior ovary
(3) Superior ovary
(4) Epigynous ovary
Explanation: The answer is (3) Superior ovary. In a hypogynous flower, the ovary occupies the highest position, while other floral parts are attached below it. This makes the ovary superior. Flowers like lily, mustard, and brinjal exhibit this type. Such arrangement helps in better exposure and pollination efficiency among various angiosperms.
6. Which one of the following pairs is correctly matched?
(1) Mustard – Polyadelphous stamens
(2) China rose – Monadelphous stamens
(3) Pea – Diadelphous stamens
(4) Sunflower – Polyandrous stamens
Explanation: The answer is (3) Pea – Diadelphous stamens. In the pea flower, nine stamens are united into one bundle while the tenth remains free, forming a (9+1) arrangement called diadelphous. This is a characteristic feature of Fabaceae family members, aiding in pollination through a unique floral morphology that ensures efficient pollen transfer.
7. Assertion–Reason Type Question:
Assertion (A): In rose, the ovary is half-inferior.
Reason (R): Floral parts are attached to the rim of a cup-shaped thalamus.
(1) Both A and R are true, and R is the correct explanation of A
(2) Both A and R are true, but R is not the correct explanation of A
(3) A is true, but R is false
(4) A is false, but R is true
Explanation: The correct answer is (1). In a rose, the cup-shaped thalamus surrounds the ovary partially, with petals, sepals, and stamens attached around its rim. This structure makes the ovary half-inferior, a characteristic feature of perigynous flowers, allowing balance between protection and exposure during pollination and fruit development.
8. Matching Type Question:
Match the following:
A. Tomato I. Axile placentation
B. Mustard II. Parietal placentation
C. Pea III. Marginal placentation
D. Cucumber IV. Parietal placentation
(1) A-I, B-II, C-III, D-IV
(2) A-II, B-IV, C-I, D-III
(3) A-IV, B-I, C-III, D-II
(4) A-I, B-IV, C-II, D-III
Explanation: The correct answer is (1) A-I, B-II, C-III, D-IV. Tomato shows axile placentation with ovules attached to a central axis, mustard exhibits parietal placentation where ovules develop on the inner wall, pea has marginal placentation, and cucumber also has parietal placentation. These variations help classify flowering plants into distinct taxonomic groups.
9. Fill in the Blanks Type Question:
The fruit of mango develops from the ______ ovary and is called a ______.
(1) Superior, drupe
(2) Inferior, berry
(3) Inferior, drupe
(4) Superior, capsule
Explanation: The answer is (1) Superior, drupe. Mango fruit develops from a monocarpellary superior ovary and is a drupe type. The pericarp is differentiated into a thin epicarp, fleshy mesocarp, and stony endocarp surrounding the seed. This structure provides protection and aids in dispersal through animals and birds effectively.
10. Choose the Correct Statements Type Question:
Statement I: Cotton shows valvate aestivation.
Statement II: In twisted aestivation, one petal overlaps the next regularly.
(1) Both statements are true
(2) Both statements are false
(3) Statement I is false, Statement II is true
(4) Statement I is true, Statement II is false
Explanation: The correct answer is (3). Cotton exhibits twisted aestivation, not valvate. In twisted aestivation, one margin of a petal overlaps the adjacent petal in a regular sequence. This arrangement helps compactly enclose floral parts in the bud and is seen in Malvaceae members such as cotton and China rose.
Topic: Pollination Mechanisms; Subtopic: Wind Pollination (Anemophily)
Keyword Definitions:
Wind Pollination (Anemophily): Pollination in which pollen grains are transferred from stamens to stigma by wind.
Stamens: Male reproductive organs of a flower consisting of anther and filament.
Cleistogamous Flowers: Flowers that remain closed and self-pollinate, ensuring autogamy.
Mucilaginous Covering: A sticky coating on pollen grains found in water-pollinated plants to prevent wetting.
Inflorescence: The arrangement of flowers on a plant, which may be compact or open.
Lead Question – 2024
Identify the correct description about the given Figure. (The figure likely depicts a sparse, open inflorescence with prominent, exposed stamens)
(1) Water pollinated flowers showing stamens with mucilaginous covering
(2) Cleistogamous flowers showing autogamy
(3) Compact inflorescence showing complete autogamy
(4) Wind pollinated plant inflorescence showing flowers with well exposed stamens
Explanation:
The figure depicts a sparse, open inflorescence with prominently exposed stamens, a characteristic feature of wind-pollinated flowers. In anemophilous plants, pollen is lightweight, produced in large quantities, and stamens and stigmas are well exposed to enhance dispersal by wind. Water-pollinated flowers have mucilaginous pollen, cleistogamous flowers remain closed, and compact inflorescences favor self-pollination. Therefore, the correct description is option (4) Wind pollinated plant inflorescence showing flowers with well exposed stamens, as this arrangement maximizes the efficiency of pollen dispersal through air currents.
1. Which adaptation is commonly found in wind-pollinated flowers?
(1) Bright petals
(2) Sticky pollen
(3) Long exposed stamens
(4) Nectar production
Explanation: Wind-pollinated flowers typically have long, exposed stamens and feathery stigmas to maximize pollen dispersal and capture. Bright petals or nectar are usually absent as they attract animal pollinators, and pollen is light and dry, not sticky. Therefore, option (3) Long exposed stamens is correct.
2. Pollen of water-pollinated flowers is often:
(1) Smooth and lightweight
(2) Covered with mucilage
(3) Large and sticky
(4) Enclosed in petals
Explanation: Water-pollinated flowers have pollen with mucilaginous covering to prevent wetting and facilitate transport in water. This protects pollen grains and ensures successful pollination. Wind-pollinated pollen is dry and light. Therefore, option (2) Covered with mucilage is correct.
3. Cleistogamous flowers are adapted for:
(1) Cross-pollination
(2) Wind pollination
(3) Self-pollination
(4) Water pollination
Explanation: Cleistogamous flowers remain closed and self-pollinate (autogamy), ensuring reproduction without relying on external pollinators. They do not expose stamens or stigmas to wind or water. Therefore, option (3) Self-pollination is correct.
4. Which feature is NOT typical of wind-pollinated flowers?
(1) Feathery stigmas
(2) Small inconspicuous petals
(3) Large quantity of pollen
(4) Nectar to attract insects
Explanation: Wind-pollinated flowers do not produce nectar, as they do not rely on insects. They have inconspicuous petals, feathery stigmas, and produce large quantities of pollen for dispersal. Therefore, option (4) Nectar to attract insects is correct as the exception.
5. Assertion–Reason Question
Assertion (A): Wind-pollinated flowers have exposed stamens and feathery stigmas.
Reason (R): These features increase efficiency of pollen dispersal and capture.
Explanation: Both Assertion and Reason are true, and the reason correctly explains the assertion. Exposed stamens release pollen into the air, and feathery stigmas trap airborne pollen, optimizing reproduction. Correct answer: Both A and R are true, R explains A.
6. Matching Type Question
Match the type of flower with its pollination mechanism:
A. Vallisneria – I. Wind
B. Maize – II. Water
C. Cleistogamous flower – III. Self
D. Hibiscus – IV. Insect
(1) A–II, B–I, C–III, D–IV
(2) A–I, B–II, C–IV, D–III
(3) A–III, B–IV, C–II, D–I
(4) A–IV, B–III, C–I, D–II
Explanation: Vallisneria is water-pollinated, maize is wind-pollinated, cleistogamous flowers self-pollinate, and hibiscus is insect-pollinated. Correct option: (1) A–II, B–I, C–III, D–IV.
7. Fill in the Blanks Question
Wind-pollinated flowers have ______ pollen and ______ stigmas.
(1) Sticky, short
(2) Light, feathery
(3) Heavy, smooth
(4) Mucilaginous, hidden
Explanation: Wind-pollinated flowers produce light, dry pollen for air dispersal and have feathery stigmas to capture airborne pollen. Option (2) Light, feathery is correct.
8. Which adaptation is common in anemophilous plants?
(1) Large, colorful petals
(2) Pollen produced in small quantities
(3) Exposed anthers and stigmas
(4) Nectar secretion
Explanation: Exposed anthers and stigmas facilitate pollen dispersal and capture in wind-pollinated plants. Colorful petals and nectar are not needed. Hence, option (3) Exposed anthers and stigmas is correct.
9. Choose the Correct Statements (Statement I & II)
Statement I: Wind-pollinated flowers produce a large quantity of pollen.
Statement II: They have sticky pollen adapted to insect transport.
Explanation: Statement I is true, as wind-pollinated flowers need abundant pollen for successful dispersal. Statement II is false; pollen is dry, not sticky. Correct answer: Statement I true, Statement II false.
10. Single Correct Answer
Which type of pollination does maize exhibit?
(1) Water pollination
(2) Wind pollination
(3) Self-pollination
(4) Insect pollination
Explanation: Maize is a classic example of a wind-pollinated plant. Its male flowers (tassels) release abundant pollen into the air, and female flowers (silks) are exposed to catch airborne pollen. Adaptations include lightweight pollen and long exposed stigmas. Therefore, option (2) Wind pollination is correct.
Topic: Androecium; Subtopic: Types of Stamens and Their Arrangement
Keyword Definitions:
Androecium: The male reproductive whorl of a flower consisting of stamens.
Stamen: The male reproductive organ of a flower composed of an anther and a filament.
Monoadelphous: All stamens united into a single bundle by their filaments.
Diadelphous: Stamens united into two bundles by their filaments, as in pea flowers.
Polyadelphous: Stamens united into more than two bundles, as seen in citrus.
Epiphyllous: Stamens attached to petals or perianth segments, found in lily and similar flowers.
Lead Question (2024):
Match List I with List II
List I (Types of stamens) List II (Example)
A. Monoadelphous I. Citrus
B. Diadelphous II. Pea
C. Polyadelphous III. Lily
D. Epiphyllous IV. China–rose
Choose the correct answer from the options given below:
(1) A–IV, B–I, C–II, D–II
(2) A–I, B–II, C–IV, D–III
(3) A–III, B–I, C–IV, D–IV
(4) A–IV, B–II, C–I, D–III
Explanation:
In China-rose, stamens are monoadelphous (fused into one bundle). In Pea, they are diadelphous (fused into two bundles). In Citrus, stamens are polyadelphous (in many bundles), while in Lily, stamens are epiphyllous (attached to petals). This arrangement helps in pollination and floral identification. Hence, the correct matching is (4).
1. Which of the following flowers shows monoadelphous stamens?
(1) Pea
(2) Citrus
(3) China-rose
(4) Lily
Explanation: In China-rose (Hibiscus rosa-sinensis), the filaments of stamens are united into a single bundle while the anthers remain free. This condition is termed monoadelphous. It helps maintain structural stability and effective pollen transfer. Therefore, the correct answer is (3) China-rose.
2. Diadelphous stamens are commonly found in:
(1) Pea
(2) Citrus
(3) Lily
(4) Mustard
Explanation: In the pea flower (Pisum sativum), stamens are united into two bundles—nine filaments are fused, and one remains free. This arrangement is called diadelphous, typical of the Fabaceae family. It ensures proper pollen presentation for pollinators. Hence, the correct answer is (1).
3. In which plant are the stamens polyadelphous?
(1) Citrus
(2) China-rose
(3) Lily
(4) Pea
Explanation: In citrus flowers, stamens are grouped into multiple bundles by their filaments, termed polyadelphous. This arrangement aids in uniform pollen dispersal and efficient fertilization. Polyadelphous stamens are a characteristic feature of members of the Rutaceae family. Hence, the correct answer is (1) Citrus.
4. Assertion (A): Epiphyllous stamens are attached to petals.
Reason (R): They arise from the receptacle and remain free from perianth.
(1) Both A and R are true, and R is the correct explanation of A.
(2) Both A and R are true, but R is not the correct explanation of A.
(3) A is true, but R is false.
(4) A is false, but R is true.
Explanation: Epiphyllous stamens are those that are fused or attached to the petals or perianth lobes, as seen in lily. They do not arise freely from the receptacle. Therefore, Assertion is true but Reason is false. The correct answer is (3).
5. Match the following floral types with their respective stamen arrangements:
A. Monadelphous – I. China-rose
B. Diadelphous – II. Pea
C. Polyadelphous – III. Citrus
D. Epiphyllous – IV. Lily
(1) A–I, B–II, C–III, D–IV
(2) A–II, B–I, C–IV, D–III
(3) A–IV, B–III, C–I, D–II
(4) A–III, B–I, C–II, D–IV
Explanation: Monadelphous stamens occur in China-rose, diadelphous in pea, polyadelphous in citrus, and epiphyllous in lily. These arrangements differ in filament fusion patterns and play a key role in flower taxonomy. The correct answer is (1).
6. In pea flowers, nine stamens are fused, and one is free. This arrangement is called:
(1) Monadelphous
(2) Diadelphous
(3) Polyadelphous
(4) Syngenesious
Explanation: The pea flower displays diadelphous condition where nine stamens form one bundle, and one remains free. This feature helps in pollination and is typical of Fabaceae family members. Therefore, the correct answer is (2).
7. Fill in the blank: In lily, the stamens are ______ because they are attached to the perianth.
(1) Epiphyllous
(2) Polyadelphous
(3) Monadelphous
(4) Diadelphous
Explanation: In lily, stamens are epiphyllous, meaning they are attached to the perianth segments. This helps in effective pollen presentation for insect pollination. This feature is characteristic of the Liliaceae family. Hence, the correct answer is (1) Epiphyllous.
8. Choose the correct statements:
Statement I: Polyadelphous stamens are present in citrus.
Statement II: Monadelphous stamens are present in pea.
(1) Both I and II are true.
(2) Both I and II are false.
(3) I is true, II is false.
(4) I is false, II is true.
Explanation: Polyadelphous stamens occur in citrus, and monadelphous stamens occur in China-rose, not pea. Pea shows diadelphous stamens. Hence, only Statement I is true, and the correct answer is (3).
9. Which of the following conditions represents stamens fused by their filaments into more than two bundles?
(1) Monadelphous
(2) Diadelphous
(3) Polyadelphous
(4) Syngenesious
Explanation: In the polyadelphous condition, stamens are united into more than two bundles by their filaments while the anthers remain free. This is typical of citrus and some members of the Rutaceae family. Hence, the correct answer is (3).
10. In China-rose, stamens are united by filaments to form one bundle. This condition is termed:
(1) Syngenesious
(2) Polyadelphous
(3) Diadelphous
(4) Monadelphous
Explanation: In China-rose, all stamens are fused together by their filaments into a single tubular structure, with free anthers. This condition is called monadelphous and represents the typical feature of Malvaceae family flowers. The correct answer is (4).
Topic: Pollination; Subtopic: Hydrophily – Pollination in Aquatic Plants
Keyword Definitions:
Hydrophily: Pollination that occurs through the agency of water.
Vallisneria: A submerged aquatic plant showing epihydrophilous pollination.
Waterlily: An aquatic plant pollinated by insects, not by water.
Pollen grains: Male gametophytes of seed plants that carry male gametes.
Hydrophytes: Plants adapted to live in aquatic environments.
Lead Question – 2024
Identify the set of correct statements:
A. The flowers of Vallisneria are colourful and produce nectar.
B. The flowers of waterlily are not pollinated by water.
C. In most of water-pollinated species, the pollen grains are protected from wetting.
D. Pollen grains of some hydrophytes are long and ribbon-like.
E. In some hydrophytes, the pollen grains are carried passively inside water.
Choose the correct answer from the options given below:
(1) A, B, C and D only
(2) A, C, D and E only
(3) B, C, D and E only
(4) C, D and E only
Explanation: The correct answer is (3) B, C, D and E only. Vallisneria flowers are not colourful and do not produce nectar. Waterlily is insect-pollinated (entomophilous). In hydrophilous species, pollen grains are protected from wetting by mucilaginous covering, are sometimes long and ribbon-like, and can be carried passively by water currents to stigmas of female flowers.
1. Which of the following is an example of epihydrophily?
(1) Vallisneria
(2) Zostera
(3) Ceratophyllum
(4) Hydrilla
Answer: (1) Vallisneria. In Vallisneria, female flowers float on the surface while male flowers are released underwater and rise to the surface for pollination. This type, called epihydrophily, occurs on the surface of water. It ensures cross-pollination and adaptation in aquatic environments where insects are absent.
2. Which of the following aquatic plants shows hypohydrophily?
(1) Vallisneria
(2) Zostera
(3) Lotus
(4) Hydrilla
Answer: (2) Zostera. Zostera, a marine angiosperm, shows hypohydrophily where pollination occurs below the water surface. Its pollen grains are long and ribbon-like, allowing easy transport through water currents. This adaptation prevents clumping and ensures efficient fertilization even in underwater conditions.
3. Which one of the following statements about hydrophilous flowers is correct?
(1) They produce nectar
(2) They are brightly coloured
(3) They are small and inconspicuous
(4) They attract insects
Answer: (3) They are small and inconspicuous. Hydrophilous flowers do not need bright colours or nectar because they depend on water for pollen transfer. The floral structures are simplified, often with reduced petals, and pollen grains are adapted to float or move with water currents efficiently.
4. Pollen grains of Zostera are:
(1) Heavy and sticky
(2) Long, ribbon-like and covered with mucilage
(3) Round and smooth
(4) Air-filled and buoyant
Answer: (2) Long, ribbon-like and covered with mucilage. Zostera pollen grains are uniquely shaped to move through water currents. The mucilage coating prevents wetting, ensuring their survival in saline environments. This is a special adaptation to achieve underwater pollination, an evolutionary modification in marine angiosperms.
5. Which of the following plants is not water-pollinated?
(1) Zostera
(2) Vallisneria
(3) Lotus
(4) Ceratophyllum
Answer: (3) Lotus. Lotus, though aquatic, is pollinated by insects (entomophilous). Its bright-coloured flowers and nectar attract pollinators. Thus, not all aquatic plants are hydrophilous; some retain features of terrestrial pollination mechanisms to enhance reproductive success through animal agents.
6. Which adaptation is seen in hydrophilous pollen grains?
(1) Spiny exine
(2) Mucilaginous covering
(3) Air sacs
(4) Wings
Answer: (2) Mucilaginous covering. Pollen grains of hydrophilous plants possess mucilage that prevents them from becoming waterlogged. This adaptation ensures buoyancy and protection, allowing pollen to reach female flowers intact even under aquatic conditions, ensuring effective fertilization without external pollinators.
7. Assertion–Reason Question
Assertion (A): Pollination in Vallisneria occurs on the surface of water.
Reason (R): Male flowers are released underwater and rise up to the surface for pollination.
(1) Both A and R are true and R is the correct explanation of A.
(2) Both A and R are true but R is not the correct explanation of A.
(3) A is true but R is false.
(4) A is false but R is true.
Answer: (1). Both statements are true, and R correctly explains A. Vallisneria is an example of surface (epihydrophilous) pollination where male flowers detach and float to the surface, meeting the female flowers that also rise above water for fertilization, aided entirely by water currents.
8. Matching Type Question
Match the following:
A. Vallisneria – (i) Submerged pollination
B. Zostera – (ii) Surface pollination
C. Waterlily – (iii) Insect pollination
D. Lotus – (iv) Floating flowers
(1) A–ii, B–i, C–iii, D–iv
(2) A–i, B–ii, C–iv, D–iii
(3) A–iii, B–iv, C–ii, D–i
(4) A–ii, B–iv, C–i, D–iii
Answer: (1). Vallisneria undergoes surface (epihydrophilous) pollination. Zostera performs submerged (hypohydrophilous) pollination. Waterlily and Lotus are insect-pollinated and have floating flowers. This table summarizes adaptations of aquatic plants in different pollination mechanisms depending on habitat and flower structure.
9. Fill in the Blanks Question
In _________, male flowers detach and float on the surface to reach female flowers for pollination.
(1) Zostera
(2) Vallisneria
(3) Lotus
(4) Hydrilla
Answer: (2) Vallisneria. In Vallisneria, male flowers are released underwater, rise to the surface, and contact the floating female flowers for pollination. This adaptation helps ensure successful fertilization without wind or insects, representing an advanced mode of hydrophily in aquatic plants.
10. Choose the Correct Statements (Statement I & II)
Statement I: Hydrophilous flowers are colourful and nectar-producing.
Statement II: Hydrophilous flowers are small, inconspicuous, and non-scented.
(1) Both statements are true.
(2) Both statements are false.
(3) Statement I is true, Statement II is false.
(4) Statement I is false, Statement II is true.
Answer: (4). Statement I is false because hydrophilous flowers do not attract pollinators and thus lack bright colours or nectar. Statement II is true as such flowers are small, non-scented, and adapted for water-mediated pollen transfer. These traits help conserve energy in aquatic environments.
Topic: Seed Structure; Subtopic: Embryo and Germination
Keyword Definitions:
Radicle: The part of a seed embryo that develops into the primary root.
Coleoptile: A sheath that protects the young shoot in monocots during germination.
Plumule: The part of the seed embryo that develops into the shoot.
Coleorhiza: A protective sheath covering the radicle in monocot seeds.
Germination: The process by which a seed develops into a new plant.
Lead Question – 2024
Identify the part of the seed from the given figure which is destined to form root when the seed germinates:
(1) B (Coleoptile)
(2) C (Plumule)
(3) D (Radicle)
(4) A (Coleorhiza)
Explanation: The radicle is the embryonic root of the seed and emerges first during germination, establishing the primary root system. The coleoptile protects the shoot, plumule forms the shoot, and coleorhiza covers the radicle in monocots but does not become the root itself. Accurate identification of the radicle is crucial to understand seedling development and early root establishment, which is essential for nutrient and water uptake. (Answer: 3)
1. Single Correct Answer:
Which part of the seed forms the shoot after germination?
(1) Radicle
(2) Coleoptile
(3) Coleorhiza
(4) Endosperm
Explanation: The shoot emerges from the plumule, which is protected by the coleoptile in monocots. The radicle forms the root, coleorhiza covers the radicle, and endosperm serves as a nutrient source. The coleoptile ensures safe emergence of the shoot through the soil. Understanding these parts is essential for studying germination and seedling development. (Answer: 2)
2. Single Correct Answer:
Which structure covers the radicle in monocot seeds?
(1) Plumule
(2) Coleoptile
(3) Coleorhiza
(4) Seed coat
Explanation: The coleorhiza is a protective sheath covering the radicle in monocot seeds. It shields the embryonic root during germination. Plumule forms the shoot, coleoptile covers the plumule, and the seed coat protects the whole seed. Correct identification is important for understanding monocot seed anatomy and root emergence processes. (Answer: 3)
3. Single Correct Answer:
Which embryonic structure absorbs nutrients from the endosperm during germination?
(1) Radicle
(2) Coleorhiza
(3) Plumule
(4) Cotyledon
Explanation: The radicle absorbs water and nutrients from the endosperm during germination to establish the primary root system. The plumule forms the shoot, coleorhiza protects the radicle, and cotyledons store nutrients. This absorption is essential for early seedling growth and root establishment. (Answer: 1)
4. Single Correct Answer:
Which structure is first to emerge during seed germination?
(1) Radicle
(2) Plumule
(3) Coleoptile
(4) Cotyledon
Explanation: The radicle is the first structure to emerge from the seed, establishing the primary root system. This ensures water and nutrient absorption to support seedling growth. Plumule forms the shoot later, coleoptile protects the plumule, and cotyledons provide stored food. Early radicle emergence is critical for seedling survival. (Answer: 1)
5. Single Correct Answer:
The plumule develops into:
(1) Root
(2) Shoot
(3) Seed coat
(4) Endosperm
Explanation: The plumule is the embryonic shoot of a seed. During germination, it develops into the above-ground parts of the plant. The radicle forms the root, seed coat protects the seed, and endosperm serves as nutrient storage. Plumule emergence ensures the shoot system develops properly. (Answer: 2)
6. Assertion-Reason:
Assertion (A): Radicle emerges first during germination.
Reason (R): Radicle absorbs water and nutrients to support seedling growth.
(1) Both A and R are true, R explains A
(2) Both A and R are true, R does not explain A
(3) A true, R false
(4) A false, R true
Explanation: The radicle is the first part of the seed to emerge, establishing the primary root system. It absorbs water and nutrients essential for seedling development. Both the assertion and reason are correct, and the reason accurately explains why the radicle emerges first. Proper understanding of radicle function is critical in plant development. (Answer: 1)
7. Matching Type:
Match List I (seed part) with List II (function):
A. Radicle – (i) Forms shoot
B. Plumule – (ii) Forms root
C. Coleoptile – (iii) Protects shoot
D. Coleorhiza – (iv) Protects radicle
Options:
(1) A-ii, B-i, C-iii, D-iv
(2) A-i, B-ii, C-iv, D-iii
(3) A-iv, B-iii, C-i, D-ii
(4) A-ii, B-i, C-iv, D-iii
Explanation: The radicle develops into the root, plumule into the shoot, coleoptile protects the plumule, and coleorhiza covers the radicle. Proper matching illustrates the function of embryonic structures in monocot seeds, ensuring correct understanding of germination and early seedling development. (Answer: 1)
8. Fill in the Blanks:
The __________ is the embryonic root that emerges first during seed germination.
(1) Coleoptile
(2) Radicle
(3) Plumule
(4) Cotyledon
Explanation: The radicle is the embryonic root and emerges first from the seed during germination. It anchors the seedling and absorbs water and nutrients, supporting early growth. The plumule develops into the shoot, coleoptile protects the plumule, and cotyledons provide food reserves. (Answer: 2)
9. Single Correct Answer:
Which part of the seed stores nutrients for germination?
(1) Radicle
(2) Plumule
(3) Endosperm
(4) Coleorhiza
Explanation: Endosperm is the tissue that stores nutrients to support germination and early seedling growth. Radicle and plumule form root and shoot, while coleorhiza protects the radicle. Nutrient storage in endosperm is critical for successful seedling establishment before photosynthesis begins. (Answer: 3)
10. Choose the Correct Statements:
Statement I: Radicle emerges first and forms the root.
Statement II: Plumule forms the shoot and is protected by coleoptile.
(1) Both statements are true
(2) Both statements are false
(3) Statement I true, Statement II false
(4) Statement I false, Statement II true
Explanation: The radicle is the first structure to emerge and forms the root, while the plumule develops into the shoot, which is protected by the coleoptile in monocots. Both statements accurately describe seedling development and germination processes. Proper identification of these structures is essential in plant anatomy. (Answer: 1)
Topic: Flower Symmetry; Subtopic: Actinomorphic and Zygomorphic Flowers
Keyword Definitions:
Actinomorphic Flower: A flower that can be divided into two equal halves along any plane passing through its center, showing radial symmetry (e.g., Datura).
Zygomorphic Flower: A flower that can be divided into two equal halves only along one specific plane (e.g., Pisum).
Radial Symmetry: Symmetry around a central axis, as in circular flowers.
Bilateral Symmetry: Symmetry along one plane, giving mirror-image halves.
Lead Question – 2024
Which of the following is an example of actinomorphic flower?
(1) Cassia
(2) Pisum
(3) Sesbania
(4) Datura
Explanation: Datura exhibits actinomorphic symmetry, meaning it can be divided into two equal halves along any plane through its center. Cassia, Pisum, and Sesbania show zygomorphic symmetry, as they can only be divided into two equal halves in one specific plane. Thus, the correct option is (4).
Guessed Question 1: Which of the following flowers is zygomorphic?
(1) Datura
(2) Hibiscus
(3) Cassia
(4) Mustard
Explanation: Cassia is zygomorphic as it can be divided into two equal halves only in one plane. Flowers like Datura, Hibiscus, and Mustard are actinomorphic because they have radial symmetry. Zygomorphy allows specialization in pollination mechanisms. Therefore, the correct option is (3).
Guessed Question 2: The symmetry shown by the flower of Hibiscus is:
(1) Zygomorphic
(2) Asymmetrical
(3) Actinomorphic
(4) Bilateral
Explanation: Hibiscus flower shows actinomorphic or radial symmetry, where any vertical plane passing through its center divides it into two identical halves. This symmetry facilitates pollination by different pollinators. Hence, the correct answer is (3).
Guessed Question 3: Which of the following is not actinomorphic?
(1) Mustard
(2) Datura
(3) Cassia
(4) Hibiscus
Explanation: Cassia is zygomorphic and not actinomorphic. It has bilateral symmetry where only one vertical section divides it into two equal halves. Mustard, Datura, and Hibiscus are actinomorphic. Thus, the correct option is (3).
Guessed Question 4: In which of the following plants is the flower asymmetrical?
(1) Canna
(2) Datura
(3) Hibiscus
(4) Mustard
Explanation: Canna shows asymmetrical flowers, which cannot be divided into equal halves by any plane. Flowers like Datura, Hibiscus, and Mustard show regular or actinomorphic symmetry. Thus, the correct answer is (1).
Guessed Question 5: Which of the following flowers shows radial symmetry?
(1) Gulmohar
(2) Datura
(3) Cassia
(4) Clitoria
Explanation: Datura has radial or actinomorphic symmetry, meaning it can be divided into equal halves by any vertical plane through the center. Gulmohar, Cassia, and Clitoria are zygomorphic flowers. Hence, the correct option is (2).
Guessed Question 6: In zygomorphic flowers, symmetry occurs:
(1) Along any plane
(2) Along only one vertical plane
(3) Along two planes
(4) Along the transverse axis
Explanation: Zygomorphic flowers exhibit bilateral symmetry, meaning they can be divided into two identical halves only by one particular vertical plane. This feature is seen in flowers like pea and Cassia. Therefore, the correct answer is (2).
Guessed Question 7 (Assertion–Reason Type):
Assertion (A): Datura flower is actinomorphic.
Reason (R): It can be divided into equal halves along any plane passing through its center.
(1) Both A and R are true, and R is the correct explanation of A
(2) Both A and R are true, but R is not the correct explanation
(3) A is true but R is false
(4) A is false but R is true
Explanation: Datura is actinomorphic as any vertical plane through the center divides it equally. Hence, both A and R are true, and R correctly explains A. Therefore, the correct option is (1).
Guessed Question 8 (Matching Type):
Match the following flowers with their symmetry:
A. Datura — I. Actinomorphic
B. Cassia — II. Zygomorphic
C. Canna — III. Asymmetrical
D. Clitoria — IV. Bilateral
Choose the correct answer:
(1) A-I, B-II, C-III, D-IV
(2) A-II, B-I, C-IV, D-III
(3) A-III, B-II, C-I, D-IV
(4) A-I, B-III, C-II, D-IV
Explanation: Datura is actinomorphic, Cassia is zygomorphic, Canna is asymmetrical, and Clitoria shows bilateral symmetry. Therefore, the correct option is (1).
Guessed Question 9 (Fill in the Blank):
A flower that can be divided into two identical halves in any plane passing through its center is called __________.
(1) Asymmetrical
(2) Actinomorphic
(3) Zygomorphic
(4) Polymorphic
Explanation: An actinomorphic flower shows radial symmetry, where any vertical plane divides it equally. Examples include Mustard, Hibiscus, and Datura. Hence, the correct answer is (2).
Guessed Question 10 (Choose the Correct Statements):
Statement I: Cassia flower can be divided equally in any plane.
Statement II: Datura flower can be divided equally in any vertical plane through the center.
(1) Both statements are true
(2) Both statements are false
(3) Statement I false, II true
(4) Statement I true, II false
Explanation: Cassia is zygomorphic and divides in only one plane, whereas Datura is actinomorphic, divisible along any vertical plane through the center. Hence, Statement I is false and Statement II is true. The correct option is (3).
Topic: Flower and Its Parts; Subtopic: Position of Floral Whorls and Ovary Types
Keyword Definitions:
Hypogynous Flower: The ovary is superior, and other floral parts are attached below it.
Epigynous Flower: The ovary is inferior, and other floral parts arise above it.
Perigynous Flower: Ovary is half-inferior; floral parts are attached around the ovary.
Ovary: The female reproductive part that develops into fruit after fertilization.
Thalamus: The base of the flower where floral whorls are attached.
Lead Question – 2024
Identify the type of flowers based on the position of calyx, corolla and androecium with respect to the ovary from the given figures (a) and (b). Hint: floral parts around the ovary
(1) (a) Hypogynous; (b) Epigynous
(2) (a) Perigynous; (b) Epigynous
(3) (a) Perigynous; (b) Perigynous
(4) (a) Epigynous; (b) Hypogynous
Explanation: The correct answer is (3) (a) Perigynous; (b) perigynous. In perigynous flowers, like rose, the ovary is half-inferior and other floral parts arise around the ovary.
Guessed Questions:
1. In hypogynous flowers, the ovary is:
(1) Superior
(2) Inferior
(3) Half-inferior
(4) Embedded in thalamus
Explanation: The correct answer is (1) Superior. In hypogynous flowers, such as mustard and china rose, the ovary occupies the highest position on the thalamus, with other floral parts like calyx, corolla, and androecium arranged below it, making the ovary free and prominent above them.
2. Which of the following correctly represents an epigynous flower?
(1) Mustard
(2) Rose
(3) Guava
(4) China rose
Explanation: The correct answer is (3) Guava. In epigynous flowers, the ovary is inferior and enclosed by the thalamus. The floral parts such as sepals, petals, and stamens appear to arise from above the ovary, as seen in guava and cucumber.
3. Match the following:
List I - Type of Flower
(A) Hypogynous
(B) Perigynous
(C) Epigynous
List II - Example
(I) China rose
(II) Rose
(III) Cucumber
Options:
(1) A–I, B–II, C–III
(2) A–II, B–I, C–III
(3) A–III, B–I, C–II
(4) A–I, B–III, C–II
Explanation: The correct answer is (1) A–I, B–II, C–III. China rose is hypogynous with a superior ovary, rose is perigynous with a half-inferior ovary, and cucumber is epigynous with an inferior ovary.
4. Assertion–Reason:
Assertion (A): In hypogynous flowers, ovary is superior.
Reason (R): The thalamus grows around the ovary in such flowers.
Options:
(1) Both A and R are true, and R is the correct explanation of A
(2) Both A and R are true, but R is not the correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Explanation: The correct answer is (3). In hypogynous flowers, the ovary is superior because it lies above other floral parts. The thalamus does not grow around the ovary in this case; it occurs in epigynous and perigynous flowers.
5. Fill in the blanks:
In perigynous flowers, the ovary is said to be ________.
(1) Superior
(2) Inferior
(3) Half-inferior
(4) Partially superior
Explanation: The correct answer is (3) Half-inferior. In perigynous flowers, the thalamus forms a cup-like structure called hypanthium that partially encloses the ovary, making it half-inferior, as seen in rose and plum.
6. Choose the correct statements:
Statement I: In hypogynous flowers, the ovary is superior.
Statement II: In epigynous flowers, the ovary is enclosed by the thalamus.
Options:
(1) Both statements are true
(2) Both statements are false
(3) Statement I is true, Statement II is false
(4) Statement I is false, Statement II is true
Explanation: The correct answer is (1). In hypogynous flowers like mustard, the ovary is superior, while in epigynous flowers like cucumber, the thalamus encloses the ovary, making it inferior.
7. Which floral type is seen in China rose?
(1) Hypogynous
(2) Epigynous
(3) Perigynous
(4) Hypergynous
Explanation: The correct answer is (1) Hypogynous. In China rose (*Hibiscus rosa-sinensis*), the ovary is superior and lies above the attachment of other floral parts, making it a typical hypogynous flower.
8. In which of the following, thalamus forms a cup-shaped structure around the ovary?
(1) Hypogynous flower
(2) Epigynous flower
(3) Perigynous flower
(4) Actinomorphic flower
Explanation: The correct answer is (3) Perigynous flower. The thalamus forms a cup-like hypanthium around the ovary, keeping it half-inferior while other floral parts arise on the rim of this cup, typical of rose and peach.
9. The condition where the ovary is completely enclosed by the thalamus is called:
(1) Hypogyny
(2) Perigyny
(3) Epigyny
(4) Polygyny
Explanation: The correct answer is (3) Epigyny. In this condition, the ovary is completely enclosed by the thalamus and other floral parts arise above it, as seen in inferior ovaries of guava and apple flowers.
10. The floral whorls in hypogynous, perigynous, and epigynous flowers differ in their:
(1) Position relative to ovary
(2) Symmetry of corolla
(3) Number of stamens
(4) Type of aestivation
Explanation: The correct answer is (1). The major difference among hypogynous, perigynous, and epigynous flowers lies in the relative position of the floral whorls to the ovary, affecting the ovary's position as superior, half-inferior, or inferior.
Topic: Types of Flowers; Subtopic: Floral Symmetry and Ovary Position
Keyword Definitions:
Zygomorphic flower: A flower that is bilaterally symmetrical and can be divided into equal halves along only one plane.
Hypogynous flower: A flower in which the ovary is superior and other floral parts arise below it.
Perigynous flower: A flower in which the ovary is half-inferior, surrounded by a floral cup called hypanthium.
Epigynous flower: A flower in which the ovary is inferior and other floral parts arise above it.
Floral Symmetry: The arrangement of floral parts that allows flowers to be divided into equal halves.
Ovule Position: The relative position of the ovary to other floral parts in a flower.
Example: A representative plant species used to illustrate a type of flower.
Lead Question – 2023 (Manipur)
Match List – I with List – II
Type of flower Example
(A) Zygomorphic (I) Mustard
(B) Hypogynous (II) Plum
(C) Perigynous (III) Cassia
(D) Epigynous (IV) Cucumber
Choose the correct answer from the options given below:
1. I II IV III
2. I II III IV
3. IV I III II
4. III I II IV
Explanation: Zygomorphic flowers are bilaterally symmetrical like Cassia, showing one plane of symmetry. Hypogynous flowers have a superior ovary, as in Mustard, with other parts below. Perigynous flowers, like Plum, have a half-inferior ovary surrounded by hypanthium. Epigynous flowers, such as Cucumber, have inferior ovaries with floral parts arising above. Correct matching is A–III, B–I, C–II, D–IV. The systematic understanding of floral symmetry and ovary position is essential in plant morphology studies. Correct answer: 4. III I II IV.
1. Single Correct Answer MCQ:
Which flower is bilaterally symmetrical?
1. Mustard
2. Cassia
3. Cucumber
4. Plum
Explanation: Cassia exhibits zygomorphic symmetry, meaning it can be divided into equal halves along only one vertical plane, unlike radially symmetrical flowers such as Mustard or Plum. Correct answer: 2. Cassia.
2. Single Correct Answer MCQ:
A flower with superior ovary is called:
1. Hypogynous
2. Epigynous
3. Perigynous
4. Zygomorphic
Explanation: In hypogynous flowers, the ovary is superior, and other floral parts arise below it. This type is exemplified by Mustard. Correct answer: 1. Hypogynous.
3. Single Correct Answer MCQ:
In which type of flower is the ovary half-inferior and surrounded by a hypanthium?
1. Epigynous
2. Perigynous
3. Hypogynous
4. Zygomorphic
Explanation: Perigynous flowers, like Plum, have a half-inferior ovary surrounded by a floral cup (hypanthium), distinguishing them from hypogynous and epigynous flowers. Correct answer: 2. Perigynous.
4. Single Correct Answer MCQ:
Which flower has an inferior ovary with other floral parts arising above it?
1. Cucumber
2. Cassia
3. Mustard
4. Plum
Explanation: Epigynous flowers, such as Cucumber, have an inferior ovary, with sepals, petals, and stamens inserted above it, unlike hypogynous flowers. Correct answer: 1. Cucumber.
5. Single Correct Answer MCQ:
Floral symmetry of Mustard is:
1. Zygomorphic
2. Actinomorphic
3. Asymmetric
4. Irregular
Explanation: Mustard flowers are actinomorphic (radially symmetrical), allowing division into equal halves along multiple planes, contrasting with zygomorphic flowers like Cassia. Correct answer: 2. Actinomorphic.
6. Single Correct Answer MCQ:
Which flower is an example of zygomorphic symmetry?
1. Mustard
2. Cassia
3. Cucumber
4. Plum
Explanation: Zygomorphic flowers like Cassia show bilateral symmetry, permitting only a single plane of division into mirror images. Correct answer: 2. Cassia.
7. Assertion-Reason MCQ:
Assertion (A): Epigynous flowers have inferior ovaries.
Reason (R): Sepals, petals, and stamens arise above the ovary in epigynous flowers.
1. Both A and R true, R explains A
2. Both A and R true, R does not explain A
3. A true, R false
4. A false, R true
Explanation: In epigynous flowers, the ovary is inferior, and all other floral parts are attached above it. The reason correctly explains the assertion. Correct answer: 1.
8. Matching Type MCQ:
Match flower types with examples:
A. Zygomorphic – (i) Cassia
B. Hypogynous – (ii) Mustard
C. Perigynous – (iii) Plum
D. Epigynous – (iv) Cucumber
1. A–i, B–ii, C–iii, D–iv
2. A–ii, B–i, C–iv, D–iii
3. A–iv, B–iii, C–i, D–ii
4. A–iii, B–i, C–ii, D–iv
Explanation: Zygomorphic flowers are Cassia, hypogynous is Mustard, perigynous is Plum, and epigynous is Cucumber. Correct answer: 4.
9. Fill in the Blanks MCQ:
A flower in which all floral parts arise below a superior ovary is called ______.
1. Epigynous
2. Hypogynous
3. Perigynous
4. Zygomorphic
Explanation: Hypogynous flowers, like Mustard, have a superior ovary with sepals, petals, and stamens attached below it. Correct answer: 2.
10. Choose the Correct Statements MCQ:
Statement I: Perigynous flowers have a half-inferior ovary surrounded by hypanthium.
Statement II: Zygomorphic flowers can be divided into equal halves along only one plane.
1. Both true
2. Both false
3. I true, II false
4. I false, II true
Explanation: Perigynous flowers like Plum have a half-inferior ovary enclosed by hypanthium, while zygomorphic flowers like Cassia show bilateral symmetry. Both statements accurately describe these floral characteristics. Correct answer: 1.
Topic: Female Gametophyte; Subtopic: Development of Embryo Sac in Angiosperms
Keyword Definitions:
Megasporogenesis: The process by which a diploid megaspore mother cell (MMC) undergoes meiosis to form four haploid megaspores.
Megagametogenesis: The development of the functional megaspore into the female gametophyte (embryo sac).
Embryo Sac: The female gametophyte in angiosperms, usually 8-nucleate and 7-celled, formed from the functional megaspore.
Synergids: Two specialized cells flanking the egg cell that help guide the pollen tube during fertilization.
Antipodals: Three cells at the chalazal end of the embryo sac, often degenerating after fertilization.
Micropylar End: The end of the ovule where the pollen tube enters for fertilization.
Polar Nuclei: Two central nuclei that fuse with a male nucleus to form triploid endosperm.
Lead Question - 2023 (Manipur)
In angiosperms, the correct sequence of events leading to the formation of female gametophyte in the ovule is:
A. 3 successive free nuclear divisions in functional megaspore.
B. Degeneration of 3 megaspores.
C. Meiotic division in megaspore mother cell.
D. Migration of 3 nuclei towards each pole.
E. Formation of a wall resulting in seven-celled embryo sac.
Choose the correct answer from the options given below:
1. (A), (B), (C), (D), (E)
2. (C), (E), (A), (D), (B)
3. (B), (C), (A), (D), (E)
4. (C), (B), (A), (D), (E)
Explanation:
In angiosperms, the correct order is: (C) Meiotic division in megaspore mother cell forming four megaspores, (B) Degeneration of three megaspores, (A) Three free nuclear divisions in the functional megaspore, (D) Migration of nuclei to poles, and (E) Wall formation leading to a seven-celled embryo sac. Correct answer: (C), (B), (A), (D), (E).
Guessed Questions:
1. Single Correct Answer Type:
How many mitotic divisions occur during the development of an embryo sac from the functional megaspore?
1. One
2. Two
3. Three
4. Four
Explanation:
The functional megaspore undergoes three successive mitotic (free nuclear) divisions, producing eight nuclei. Later, cellular organization forms a seven-celled embryo sac. Thus, the correct answer is three mitotic divisions, characteristic of the Polygonum-type embryo sac formation.
2. Single Correct Answer Type:
In a typical angiosperm embryo sac, how many nuclei and cells are present?
1. 7 cells, 7 nuclei
2. 8 cells, 7 nuclei
3. 7 cells, 8 nuclei
4. 8 cells, 8 nuclei
Explanation:
A mature embryo sac in angiosperms consists of 7 cells and 8 nuclei. These include one egg cell, two synergids, three antipodals, and one central cell containing two polar nuclei. Thus, the correct answer is 7 cells and 8 nuclei.
3. Single Correct Answer Type:
Which type of embryo sac is most common in angiosperms?
1. Oenothera type
2. Allium type
3. Polygonum type
4. Monosporic type
Explanation:
The most common type of embryo sac is the Polygonum type, which is monosporic and derived from a single functional megaspore. It represents the standard seven-celled, eight-nucleate structure found in most flowering plants. Correct answer: Polygonum type.
4. Single Correct Answer Type:
The functional megaspore develops into which structure?
1. Ovule
2. Embryo sac
3. Egg cell
4. Endosperm
Explanation:
The functional megaspore undergoes three mitotic divisions to form the female gametophyte, known as the embryo sac. This structure contains the egg apparatus, antipodals, and polar nuclei essential for fertilization. Therefore, the correct answer is embryo sac.
5. Single Correct Answer Type:
The female gametophyte in angiosperms develops from:
1. Megaspore mother cell
2. One of the megaspores
3. All four megaspores
4. Ovary wall
Explanation:
Out of the four haploid megaspores formed by meiotic division, only one remains functional while the other three degenerate. The single functional megaspore gives rise to the embryo sac, the female gametophyte. Thus, the correct answer is one of the megaspores.
6. Single Correct Answer Type:
Which among the following represents the correct location of egg apparatus in the embryo sac?
1. At the chalazal end
2. At the micropylar end
3. In the central cell
4. Near antipodal cells
Explanation:
The egg apparatus, consisting of one egg cell and two synergids, is located at the micropylar end of the embryo sac. This position facilitates fertilization as the pollen tube enters through the micropyle. Correct answer: At the micropylar end.
7. Assertion-Reason Type:
Assertion (A): In angiosperms, the embryo sac is 8-nucleate and 7-celled.
Reason (R): Two polar nuclei fuse to form a single diploid secondary nucleus.
1. Both A and R are true, and R is the correct explanation of A
2. Both A and R are true, but R is not the correct explanation of A
3. A is true but R is false
4. A is false but R is true
Explanation:
Both statements are true, but R does not explain A completely. The embryo sac is 8-nucleate and 7-celled due to the arrangement of nuclei after three mitotic divisions. Fusion of polar nuclei forms a diploid secondary nucleus later. Correct answer: Option 2.
8. Matching Type:
Match the following components of the embryo sac with their positions:
A. Egg apparatus — 1. Chalazal end
B. Antipodals — 2. Central cell
C. Polar nuclei — 3. Micropylar end
1. A-3, B-1, C-2
2. A-1, B-2, C-3
3. A-2, B-3, C-1
4. A-3, B-2, C-1
Explanation:
The egg apparatus is found at the micropylar end (A-3), antipodals at the chalazal end (B-1), and polar nuclei in the central cell (C-2). This arrangement supports double fertilization during reproduction. Correct match: A-3, B-1, C-2.
9. Fill in the Blanks:
The embryo sac in angiosperms is usually _______ in origin.
1. Tetrasporic
2. Bisporic
3. Monosporic
4. Multisporic
Explanation:
The embryo sac in most angiosperms is monosporic in origin, meaning it develops from a single functional megaspore after three mitotic divisions. This is the most common type found in flowering plants. Correct answer: Monosporic.
10. Choose the Correct Statements:
Statement I: The embryo sac of angiosperms is haploid.
Statement II: The polar nuclei fuse to form a triploid nucleus.
1. Both statements are true
2. Both statements are false
3. Statement I true, II false
4. Statement I false, II true
Explanation:
Statement I is true because the embryo sac is haploid, derived from a haploid megaspore. Statement II is false because polar nuclei fuse to form a diploid secondary nucleus, not triploid. The triploid endosperm forms only after fertilization. Correct answer: Option 3.
Topic: Pollination Types; Subtopic: Self-pollination and Cross-pollination
Pollen Grain: Male gametophyte containing sperm cells for fertilization.
Anther: Part of stamen producing pollen grains.
Stigma: Receptive tip of the carpel where pollen lands and germinates.
Autogamy: Self-pollination within the same flower.
Geitonogamy: Transfer of pollen between different flowers of the same plant.
Xenogamy: Cross-pollination between flowers of different plants.
Cleistogamy: Pollination in closed, self-pollinating flowers without opening.
Pollination: Transfer of pollen from anther to stigma, essential for sexual reproduction.
Fertilization: Fusion of male and female gametes forming zygote.
Cross-pollination: Pollination involving two genetically different plants, enhancing diversity.
Self-pollination: Pollination within the same flower or plant, producing genetically similar offspring.
Lead Question - 2023 (Manipur)
Transfer of pollen grains from anther to stigma of another flower of same plant is known as:
1. Geitonogamy
2. Xenogamy
3. Autogamy
4. Cleistogamy
Explanation: Transfer of pollen from anther to stigma of another flower on the same plant is called geitonogamy, a type of self-pollination that involves different flowers of the same individual. Autogamy occurs within the same flower, xenogamy involves different plants, and cleistogamy occurs in closed flowers. Geitonogamy maintains genetic similarity but allows pollen dispersal between flowers. Correct answer: 1. Geitonogamy. It is significant for reproduction in plants with multiple flowers per plant, facilitating pollen transfer by insects or wind while preserving genetic consistency.
1. Pollination in hibiscus is primarily:
a) Autogamy
b) Geitonogamy
c) Xenogamy
d) Cleistogamy
Explanation: Hibiscus is typically cross-pollinated by insects (xenogamy), as flowers are large, colorful, and offer nectar, attracting pollinators. Autogamy or cleistogamy is uncommon in hibiscus. Geitonogamy can occur if multiple flowers are present on the same plant but is not the primary mode. Correct answer: c.
2. Cleistogamous flowers are advantageous because they:
a) Promote cross-pollination
b) Reduce pollen wastage
c) Require pollinators
d) Increase genetic variation
Explanation: Cleistogamous flowers remain closed and self-pollinate, ensuring fertilization without relying on pollinators and reducing pollen wastage. They do not promote cross-pollination or increase genetic variation. This adaptation is energy-efficient and guarantees seed production. Correct answer: b.
3. Autogamy ensures:
a) Genetic variation
b) Self-fertilization within the same flower
c) Cross-fertilization between plants
d) Insect-mediated pollen transfer
Explanation: Autogamy is self-pollination within the same flower, ensuring fertilization even in absence of pollinators. It maintains genetic similarity, does not provide genetic variation or cross-fertilization, and does not require insects. Correct answer: b.
4. Xenogamy enhances:
a) Genetic uniformity
b) Genetic variation
c) Self-fertilization
d) Cleistogamy
Explanation: Xenogamy, cross-pollination between different plants, promotes genetic variation by combining alleles from different parents. It does not lead to uniformity, self-fertilization, or cleistogamy. This mechanism enhances adaptability and evolution of plant species. Correct answer: b.
5. Example of a geitonogamous plant is:
a) Pea (Pisum sativum)
b) Hibiscus
c) Maize
d) Wheat
Explanation: Pea plants have multiple flowers per plant, allowing pollen transfer between flowers on the same individual, a process called geitonogamy. Hibiscus, maize, and wheat primarily undergo cross-pollination or self-pollination within the same flower. Correct answer: a.
6. Wind pollinated flowers are usually:
a) Large and colorful
b) Small and inconspicuous
c) Fragrant with nectar
d) Cleistogamous
Explanation: Wind-pollinated flowers are small, inconspicuous, and lack bright colors or fragrance because they do not attract pollinators. Cleistogamy is unrelated to wind dispersal. Small and lightweight pollen aids wind dispersal. Correct answer: b.
7. Assertion (A): Geitonogamy is considered a type of self-pollination.
Reason (R): Pollen is transferred between flowers of the same plant, not between different plants.
a) Both A and R are true, and R is the correct explanation of A
b) Both A and R are true, but R is not the correct explanation of A
c) A is true, R is false
d) A is false, R is true
Explanation: Geitonogamy involves pollen transfer between flowers of the same plant and is a form of self-pollination because the genetic material originates from a single individual. This ensures fertilization without introducing new alleles. Both assertion and reason are true, and the reason correctly explains the assertion. Correct answer: a.
8. Match the following:
Column I: 1. Autogamy 2. Geitonogamy 3. Xenogamy 4. Cleistogamy
Column II: a. Self-pollination within same flower b. Cross-pollination between plants c. Pollination between flowers of same plant d. Pollination in closed flowers
Choices:
a) 1-a, 2-c, 3-b, 4-d
b) 1-c, 2-a, 3-d, 4-b
c) 1-b, 2-d, 3-a, 4-c
d) 1-d, 2-b, 3-c, 4-a
Explanation: Autogamy is self-pollination within a flower (1-a), geitonogamy occurs between flowers of the same plant (2-c), xenogamy is cross-pollination between different plants (3-b), and cleistogamy occurs in closed flowers (4-d). Correct matching: 1-a, 2-c, 3-b, 4-d. Correct answer: a.
9. Fill in the blank: Transfer of pollen from anther to stigma of another flower on the same plant is called ____________.
a) Autogamy
b) Geitonogamy
c) Xenogamy
d) Cleistogamy
Explanation: Geitonogamy is defined as the transfer of pollen between flowers of the same plant, a type of self-pollination that facilitates reproduction without introducing new genetic material. Autogamy occurs within the same flower, xenogamy between different plants, and cleistogamy in closed flowers. Correct answer: b.
10. Choose the correct statements:
Statement I: Xenogamy promotes genetic diversity.
Statement II: Geitonogamy is a form of self-pollination.
a) Both Statement I and Statement II are correct
b) Statement I is correct, Statement II is incorrect
c) Statement I is incorrect, Statement II is correct
d) Both Statement I and Statement II are incorrect
Explanation: Xenogamy involves cross-pollination between different plants, enhancing genetic diversity. Geitonogamy, pollen transfer between flowers of the same plant, is a form of self-pollination maintaining genetic similarity. Both statements are correct, highlighting the contrast between cross-pollination and self-pollination strategies in plants. Correct answer: a.
Topic: Pollination and Pollen Biology; Subtopic: Pollen Viability and Storage
Pollen Grain: Male gametophyte of seed plants containing sperm cells for fertilization.
Viability: The ability of pollen to germinate and successfully fertilize ovules over time.
Solanaceae: A plant family including tomato, potato, and tobacco.
Poaceae: Grass family including wheat, rice, and maize, with long-lived pollen grains.
Liliaceae: Lily family, monocot plants with relatively long-lasting pollen.
Brassicaceae: Mustard family including cabbage and mustard with short-lived pollen.
Rosaceae: Rose family including apple, peach, and rose; pollen viability is limited.
Leguminosae: Fabaceae family with typical legume flowers.
Fertilization: Fusion of male and female gametes leading to seed formation.
Pollination: Transfer of pollen from anther to stigma, either by wind, insects, or other agents.
Pollen Storage: Techniques to preserve pollen for breeding programs, artificial pollination, or research.
Lead Question - 2023 (Manipur)
In which of the following sets of families, the pollen grain are viable for months?
1. Solanaceae, Poaceae and Liliaceae
2. Brassicaceae, Liliaceae and Poaceae
3. Rosaceae, Liliaceae and Poaceae
4. Leguminosae, Solanaceae and Rosaceae
Explanation: Pollen viability depends on family characteristics. Poaceae and Liliaceae produce pollen that remains viable for several months, aiding cross-pollination and hybridization programs. Solanaceae pollen is generally short-lived. Brassicaceae and Rosaceae families have pollen with limited viability. Therefore, families like Poaceae and Liliaceae are noted for long-lasting pollen. Correct answer: 1. Solanaceae, Poaceae and Liliaceae. Long-term viability facilitates breeding programs, storage for artificial pollination, and genetic improvement of crops, especially in cereals and lilies, whereas short-lived pollen limits immediate fertilization opportunities.
1. Which factor most affects pollen viability?
a) Temperature and humidity
b) Soil type
c) Leaf size
d) Root depth
Explanation: Temperature and humidity critically affect pollen viability. High humidity or temperature fluctuations reduce longevity by causing premature germination or desiccation. Soil type, leaf size, or root depth do not directly influence pollen survival. Maintaining optimal storage conditions preserves viability for artificial pollination or research. Correct answer: a.
2. Pollen grains of Poaceae are adapted for:
a) Insect pollination
b) Wind pollination
c) Self-pollination only
d) Water pollination
Explanation: Poaceae (grasses) produce small, lightweight, and abundant pollen adapted for wind pollination (anemophily). Insect pollination, self-pollination, and water pollination are not typical in most Poaceae members. The pollen is often long-lived to withstand environmental conditions and ensure fertilization across distances. Correct answer: b.
3. Which family produces large, sticky pollen suitable for insect pollination?
a) Liliaceae
b) Poaceae
c) Solanaceae
d) Brassicaceae
Explanation: Solanaceae produce large, sticky pollen that adheres to insects for cross-pollination (entomophily). Poaceae are wind-pollinated, Liliaceae produce dry pollen, and Brassicaceae pollen is small and light. Sticky pollen enhances transfer efficiency and reproductive success. Correct answer: c.
4. The primary reason for long-term pollen storage in Liliaceae is:
a) Hybridization and breeding programs
b) Soil enrichment
c) Photosynthesis
d) Root development
Explanation: Long-term pollen storage allows hybridization and breeding programs in lilies, enabling controlled fertilization even when flowers do not bloom simultaneously. Soil enrichment, photosynthesis, or root development are unrelated to pollen storage. Correct answer: a.
5. Viable pollen is crucial for:
a) Seed set and reproduction
b) Leaf growth
c) Stem elongation
d) Root branching
Explanation: Viable pollen ensures successful fertilization, seed set, and reproduction. It is directly involved in sexual reproduction. Leaf growth, stem elongation, and root branching are independent vegetative processes. Pollen viability is therefore essential for maintaining species continuity and crop productivity. Correct answer: a.
6. Which storage condition best preserves pollen viability for months?
a) High humidity and warm temperature
b) Low humidity and low temperature
c) Dry soil
d) Sunlight exposure
Explanation: Low humidity and low temperature reduce metabolic activity and prevent desiccation, preserving pollen viability for months. High humidity or warmth promotes germination or degradation. Dry soil or sunlight exposure is insufficient to maintain viability. Correct answer: b.
7. Assertion (A): Poaceae pollen grains remain viable for several months.
Reason (R): They are small, dry, and lightweight, adapted to wind dispersal.
a) Both A and R are true, and R is the correct explanation of A
b) Both A and R are true, but R is not the correct explanation of A
c) A is true, R is false
d) A is false, R is true
Explanation: Poaceae pollen is adapted for wind pollination, being small, dry, and lightweight, which contributes to long-term viability for several months. Both assertion and reason are true, with reason correctly explaining the assertion. This adaptation ensures fertilization over large distances. Correct answer: a.
8. Match the following:
Column I: 1. Poaceae 2. Liliaceae 3. Solanaceae
Column II: a. Wind pollinated, long viability b. Insect pollinated, sticky pollen c. Monocot, moderately long viability
Choices:
a) 1-a, 2-c, 3-b
b) 1-c, 2-a, 3-b
c) 1-b, 2-c, 3-a
d) 1-a, 2-b, 3-c
Explanation: Poaceae are wind-pollinated with long pollen viability (1-a), Liliaceae are monocots with moderately long viability (2-c), and Solanaceae are insect-pollinated with sticky pollen (3-b). Correct matching: 1-a, 2-c, 3-b. This classification helps understand pollen storage and breeding. Correct answer: a.
9. Fill in the blank: ____________ pollen grains are generally dry, lightweight, and suitable for long-term storage.
a) Poaceae
b) Solanaceae
c) Rosaceae
d) Brassicaceae
Explanation: Poaceae pollen grains are dry, lightweight, and adapted for wind dispersal, allowing viability to last for several months. Solanaceae and Rosaceae pollen are sticky or short-lived, and Brassicaceae pollen does not remain viable for extended periods. Correct answer: a.
10. Choose the correct statements:
Statement I: Liliaceae pollen can remain viable for months under proper conditions.
Statement II: Pollen viability is influenced by temperature and humidity.
a) Both Statement I and Statement II are correct
b) Statement I is correct, Statement II is incorrect
c) Statement I is incorrect, Statement II is correct
d) Both Statement I and Statement II are incorrect
Explanation: Liliaceae pollen, under low temperature and low humidity, can remain viable for months. Environmental factors like temperature and humidity critically affect pollen viability, influencing fertilization success and breeding. Both statements are correct, highlighting the importance of storage conditions and family characteristics in reproductive biology. Correct answer: a.
Topic: Flower Structure; Subtopic: Papilionaceous Flowers and Petal Arrangement
Pea Flower: A flower of Pisum sativum, typical of papilionaceous flowers with specialized petal arrangement.
Petals: Modified leaves of a flower, usually colorful, which protect reproductive organs and attract pollinators.
Standard: The large, posterior petal of a papilionaceous flower also called vexillum.
Wings: Two lateral petals that help in guiding pollinators.
Keel: Two anterior petals fused together enclosing reproductive organs, also called carina.
Papilionaceous Flower: Bilaterally symmetrical flower typical of Fabaceae with specialized petal arrangement: standard, wings, and keel.
Posterior Petal: The petal at the back of the flower, often the standard or vexillum.
Lateral Petals: Petals located on the sides of the flower, called wings.
Anterior Petals: Petals positioned in front, fused to form keel enclosing stamens and carpels.
Carina: Another term for keel petals in papilionaceous flowers.
Fabaceae: The legume family, also called Papilionaceae, known for pea-type flowers.
Lead Question - 2023 (Manipur)
In a pea flower, five petals are arranged in a specialized manner with one posterior, two lateral and two anterior. These are named as___________, ____________ and ________ respectively.
1. Keel, Wings and standard
2. Vexillum, Keel and standard
3. Keel, Standard and Carina
4. Standard, Wings and Keel
Explanation: In papilionaceous flowers like pea, the posterior petal is the largest and is called the standard or vexillum, the lateral petals are wings, and the two anterior petals fused together form the keel or carina enclosing reproductive organs. This arrangement helps in pollination by guiding pollinators. Correct answer: 4. Standard, Wings and Keel accurately describe posterior, lateral, and anterior petals respectively. Such arrangement is characteristic of Fabaceae family flowers and aids efficient reproductive success by protecting stamens and carpels while attracting pollinators.
1. Which type of symmetry is shown by pea flowers?
a) Radial symmetry
b) Bilateral symmetry
c) Asymmetry
d) Spiral symmetry
Explanation: Pea flowers exhibit bilateral symmetry (zygomorphic), meaning they can be divided into equal halves along only one plane. This is typical of papilionaceous flowers in Fabaceae, aiding pollinator guidance. Radial symmetry (actinomorphic) occurs in flowers like mustard. Asymmetrical flowers lack symmetry and spiral symmetry is a rare arrangement. Correct answer: b.
2. The two anterior petals of a pea flower are fused to form:
a) Standard
b) Wings
c) Keel
d) Calyx
Explanation: The two anterior petals of pea flowers are fused to form the keel (carina) which encloses stamens and carpels, protecting reproductive organs. The standard is the posterior petal, wings are lateral, and calyx consists of sepals. This structural adaptation ensures effective pollination. Correct answer: c.
3. The function of wing petals in pea flowers is:
a) Photosynthesis
b) Protecting sepals
c) Guiding pollinators
d) Producing nectar
Explanation: The two lateral wing petals guide pollinators towards the reproductive structures and facilitate pollination. They do not perform photosynthesis directly or protect sepals. Nectar is produced in nectaries, not in wings. Wings are essential for proper positioning of insects on the keel for effective pollen transfer. Correct answer: c.
4. The largest petal in pea flower is called:
a) Wings
b) Keel
c) Standard or vexillum
d) Carina
Explanation: The largest posterior petal is called the standard or vexillum. It acts as a banner to attract pollinators and is characteristic of papilionaceous flowers. Wings are lateral, keel (carina) are fused anterior petals enclosing reproductive organs. Correct answer: c.
5. Papilionaceous flowers are typical of which plant family?
a) Solanaceae
b) Fabaceae
c) Liliaceae
d) Poaceae
Explanation: Papilionaceous flowers with standard, wings, and keel are characteristic of Fabaceae (legume family). This specialized petal arrangement helps in efficient pollination. Solanaceae, Liliaceae, and Poaceae have different floral structures without papilionaceous arrangement. Correct answer: b.
6. Which structure in pea flower encloses stamens and carpels?
a) Standard
b) Wings
c) Keel
d) Sepals
Explanation: The keel (carina) formed by fused anterior petals encloses stamens and carpels, protecting reproductive organs and aiding in pollination. Standard is posterior, wings are lateral, and sepals form calyx. This fusion ensures correct positioning of pollinators for pollen transfer. Correct answer: c.
7. Assertion (A): Papilionaceous flowers are zygomorphic.
Reason (R): They have unequal petal arrangement with standard, wings, and keel.
a) Both A and R are true, and R is the correct explanation of A
b) Both A and R are true, but R is not the correct explanation of A
c) A is true, R is false
d) A is false, R is true
Explanation: Papilionaceous flowers exhibit bilateral symmetry (zygomorphic) because the petals are unequal: standard (posterior), wings (lateral), keel (anterior). This unique arrangement guides pollinators effectively. Both assertion and reason are true, with reason accurately explaining the assertion. Correct answer: a.
8. Match the following:
Column I: 1. Standard 2. Wings 3. Keel
Column II: a. Lateral petals b. Posterior petal c. Fused anterior petals
Choices:
a) 1-b, 2-a, 3-c
b) 1-c, 2-b, 3-a
c) 1-a, 2-c, 3-b
d) 1-b, 2-c, 3-a
Explanation: The standard is the posterior petal, wings are the two lateral petals, and keel (carina) consists of fused anterior petals enclosing reproductive organs. Correct matching is 1-b, 2-a, 3-c. This arrangement is characteristic of Fabaceae flowers ensuring effective pollination. Correct answer: a.
9. Fill in the blank: The papilionaceous flower is ____________ in symmetry and belongs to the ____________ family.
a) Radial, Solanaceae
b) Bilateral, Fabaceae
c) Bilateral, Liliaceae
d) Radial, Fabaceae
Explanation: Papilionaceous flowers are bilaterally symmetrical (zygomorphic) and characteristic of Fabaceae. This symmetry arises due to unequal petals: standard, wings, and keel. Solanaceae and Liliaceae have actinomorphic flowers. Correct answer: b.
10. Choose the correct statements:
Statement I: Keel petals enclose stamens and carpels.
Statement II: Wings and standard petals assist in pollinator attraction and guidance.
a) Both Statement I and Statement II are correct
b) Statement I is correct, Statement II is incorrect
c) Statement I is incorrect, Statement II is correct
d) Both Statement I and Statement II are incorrect
Explanation: Keel petals, formed by fused anterior petals, enclose reproductive organs ensuring protection. Wings guide pollinators, and the standard (posterior petal) attracts them. Both statements accurately describe petal functions in papilionaceous flowers, aiding pollination efficiency. Correct answer: a.
Topic: Floral Characters; Subtopic: Aestivation
Keyword Definitions:
• Aestivation: Arrangement of sepals or petals in a flower bud before it opens.
• Valvate aestivation: Margins of petals or sepals touch each other without overlapping.
• Imbricate aestivation: Overlapping arrangement of petals or sepals in a bud.
• Twisted aestivation: Each petal overlaps the next in a spiral manner.
• Vexillary aestivation: Characteristic of papilionaceous flowers with standard, wings, and keel petals.
• Calotropis: A genus of flowering plants in Apocynaceae with large flowers, commonly called milkweed.
• Floral morphology: Study of structure, arrangement, and types of flowers and floral parts.
• Bud: Immature floral structure where aestivation can be observed.
Lead Question - 2023 (Manipur)
In Calotropis, aestivation is:
Options:
1. Valvate
2. Vexillary
3. Imbricate
4. Twisted
Answer & Explanation: Option 1. In Calotropis, the petals of the flower bud show valvate aestivation, where the margins of petals touch each other without overlapping. This type of aestivation is characteristic of many members of the Apocynaceae family. Understanding aestivation helps in identifying plant species, studying evolutionary relationships, and explaining floral adaptations for pollination. The bud structure determines how petals unfold during anthesis, influencing flower display and reproductive success. Knowledge of valvate, imbricate, twisted, and vexillary arrangements is important for botanical classification, floral morphology studies, and practical plant identification in taxonomy and horticulture.
1. Single Correct Answer MCQ
Which type of aestivation is characteristic of the Fabaceae family?
Options:
A. Valvate
B. Vexillary
C. Imbricate
D. Twisted
Answer & Explanation: Option B. Fabaceae family flowers exhibit vexillary or papilionaceous aestivation, where the standard petal overlaps the two wing petals and the keel is enclosed. This arrangement enhances pollination efficiency by guiding pollinators. Understanding floral aestivation is key to taxonomy, evolutionary biology, and identifying plant families. The vexillary pattern allows flower petals to unfold sequentially, providing structural support and optimizing reproductive success. Recognizing this type is essential in morpho-anatomical studies, teaching plant identification, and understanding adaptive strategies of angiosperms.
2. Single Correct Answer MCQ
Twisted aestivation is observed in which of the following plants?
Options:
A. Hibiscus
B. Calotropis
C. Pisum
D. Mustard
Answer & Explanation: Option A. In Hibiscus, the petals exhibit twisted aestivation where each petal overlaps the next in a spiral fashion. Calotropis shows valvate aestivation, Pisum has vexillary, and mustard exhibits quincuncial arrangement. Twisted aestivation affects how flowers open and present themselves to pollinators. Recognizing these patterns aids in botanical identification, floral morphology studies, and understanding evolutionary relationships among plant families. Detailed knowledge of aestivation types is essential for taxonomy, comparative botany, and practical applications in horticulture, breeding, and ecological research.
3. Single Correct Answer MCQ
Imbricate aestivation is typical of which flower?
Options:
A. Cassia
B. Calotropis
C. Pisum
D. Hibiscus
Answer & Explanation: Option A. Cassia exhibits imbricate aestivation where petals overlap each other. In this type, some petals lie inside and some outside. This arrangement protects inner floral parts and aids in sequential petal opening. Understanding imbricate, valvate, twisted, and vexillary types is crucial for plant classification, morphology studies, and identifying floral adaptations. Observing bud structure and petal arrangements allows botanists to distinguish closely related species and families. Imbricate aestivation provides insights into pollination mechanisms, floral evolution, and reproductive strategies in angiosperms.
4. Single Correct Answer MCQ
Which of the following is not an aestivation type?
Options:
A. Valvate
B. Spiral
C. Vexillary
D. Quadrangular
Answer & Explanation: Option D. Quadrangular is not a recognized type of floral aestivation. Valvate, spiral (twisted), and vexillary are established arrangements of petals or sepals in flower buds. Knowledge of correct aestivation types is essential for taxonomy, plant identification, and floral morphology studies. Observing bud arrangements helps understand species characteristics, evolutionary relationships, and floral adaptations. Recognizing invalid or uncommon terms prevents errors in classification, identification, and botanical documentation. Proper understanding is crucial for teaching, research, and ecological applications involving angiosperm reproductive structures.
5. Single Correct Answer MCQ
Which floral family commonly exhibits valvate aestivation?
Options:
A. Malvaceae
B. Fabaceae
C. Solanaceae
D. Brassicaceae
Answer & Explanation: Option A. Malvaceae family, including Hibiscus and Bombax, often shows valvate aestivation where petal margins meet without overlapping. Valvate arrangement influences flower opening patterns and pollinator access. Fabaceae exhibits vexillary, Solanaceae usually shows twisted or imbricate, and Brassicaceae exhibits quincuncial aestivation. Recognizing family-specific aestivation types aids in plant classification, floral morphology research, and practical identification. Floral arrangements affect reproductive success, anthesis, and pollination strategies, making aestivation knowledge essential for botanists, horticulturists, and students studying angiosperm diversity and structural adaptations.
6. Single Correct Answer MCQ
In twisted aestivation, how do petals overlap?
Options:
A. Edges touch only
B. Each petal overlaps the next in a spiral
C. One petal completely inside others
D. Standard petal covers wings and keel
Answer & Explanation: Option B. Twisted aestivation features petals overlapping sequentially in a spiral pattern, influencing flower opening. This arrangement provides structural stability, protects inner floral organs, and guides pollinators. Knowledge of twisted aestivation is important for floral morphology, taxonomy, and evolutionary studies. Comparing twisted, valvate, imbricate, and vexillary types highlights angiosperm diversity. Recognizing these patterns aids in practical identification, research in reproductive biology, and understanding floral adaptations across ecological and evolutionary contexts. The spiral overlap ensures orderly petal unfolding during anthesis, enhancing reproductive efficiency.
7. Assertion-Reason MCQ
Assertion (A): Calotropis exhibits valvate aestivation.
Reason (R): In valvate aestivation, petal margins just touch without overlapping.
Options:
A. Both A and R are true, R is the correct explanation of A
B. Both A and R are true, R is not the correct explanation of A
C. A is true, R is false
D. A is false, R is true
Answer & Explanation: Option A. In Calotropis, petals show valvate aestivation, where margins touch without overlap, protecting inner floral parts while allowing efficient opening. This arrangement is significant in Malvaceae and Apocynaceae. Understanding valvate patterns is essential for classification, floral morphology studies, and identifying angiosperm species. The arrangement ensures sequential petal unfolding and facilitates pollinator access. Observing bud aestivation provides insights into evolutionary adaptations, species relationships, and reproductive strategies, emphasizing the structural and functional significance of valvate arrangements in flowering plants.
8. Matching Type MCQ
Match the following plants with their type of aestivation:
List-I List-II
(A) Calotropis (I) Imbricate
(B) Hibiscus (II) Twisted
(C) Pisum (III) Vexillary
(D) Cassia (IV) Valvate
Options:
1. A-IV, B-II, C-III, D-I
2. A-II, B-I, C-IV, D-III
3. A-III, B-IV, C-II, D-I
4. A-I, B-III, C-II, D-IV
Answer & Explanation: Option 1. Calotropis shows valvate aestivation (IV), Hibiscus twisted (II), Pisum vexillary (III), and Cassia imbricate (I). Matching plants with aestivation types helps in floral morphology studies, taxonomic identification, and understanding evolutionary relationships. Recognizing these patterns provides insight into flower structure, reproductive strategies, and pollination mechanisms. Observing bud arrangements and petal overlaps is essential for botanists and students studying angiosperm diversity, floral adaptations, and species-specific characteristics within families.
9. Fill in the Blanks / Completion MCQ
In vexillary aestivation, the largest petal is called _______.
Options:
A. Keel
B. Wing
C. Standard
D. Sepal
Answer & Explanation: Option C. In vexillary aestivation, characteristic of Fabaceae, the largest petal is called the standard. The wings and keel petals are smaller and arranged accordingly to facilitate pollination. Understanding vexillary and other aestivation types is critical in floral morphology, taxonomy, and plant identification. The standard petal’s prominence affects flower display, guides pollinators, and aids reproduction. Studying petal arrangement enhances comprehension of evolutionary adaptations, species differentiation, and reproductive success in angiosperms, providing practical knowledge for horticulture, ecology, and biodiversity studies.
10. Choose the Correct Statements MCQ
Statement I: Valvate aestivation has petals with touching edges without overlap.
Statement II: Twisted aestivation has petals overlapping each other in a spiral.
Options:
A. Both I and II are correct
B. Only I is correct
C. Only II is correct
D. Both I and II are incorrect
Answer & Explanation: Option A. Valvate aestivation features petals touching without overlapping, as in Calotropis, while twisted aestivation shows spiral overlap, as in Hibiscus. Recognizing these patterns is crucial for flower identification, morphology studies, and taxonomy. Each type affects flower opening, protection of reproductive organs, and pollinator interactions. Understanding aestivation types also aids in evolutionary biology, comparative botany, and practical plant identification, highlighting how structural arrangements of petals contribute to reproductive strategies and successful anthesis in angiosperms.
Keyword Definitions:
Axile Placentation: Arrangement where ovules are attached to a central axis in a compound ovary with multiple locules.
Tomato: Solanaceae plant showing axile placentation.
Dianthus: Caryophyllaceae plant exhibiting axile placentation.
Pea: Fabaceae family member showing axile placentation.
China Rose: Hibiscus, Malvaceae plant with marginal placentation.
Petunia: Solanaceae plant with parietal placentation.
Lemon: Citrus fruit with axile placentation.
Mustard: Brassicaceae plant with siliqua and parietal placentation.
Cucumber: Cucurbitaceae plant showing parietal placentation.
Primrose: Primulaceae plant with marginal placentation.
Lupin: Fabaceae plant with marginal or axial placentation depending on species.
Lead Question - 2023:
Axile placentation is observed in:
(1) Tomato, Dianthus and Pea
(2) China rose, Petunia and Lemon
(3) Mustard, Cucumber and Primrose
(4) China rose, Beans and Lupin
Answer & Explanation: (1) Tomato, Dianthus and Pea. Axile placentation occurs in compound ovaries with multiple locules, where ovules are attached to the central axis. Tomato, Dianthus, and Pea are classic examples showing axile placentation. This type allows even distribution of ovules within locules. Other options show parietal or marginal placentation types. Proper identification of placentation is important in botany, plant breeding, and reproductive studies. Recognizing axile placentation involves observing the ovary’s internal structure, locules, and attachment of ovules, which is crucial for morphological classification and systematic botany studies.
1. In which of the following plants is axile placentation found?
(1) Tomato
(2) Cucumber
(3) Mustard
(4) China rose
Explanation: Tomato has a compound ovary with ovules attached to central axis, showing axile placentation. Correct answer is (1).
2. Parietal placentation is exhibited by:
(1) Tomato
(2) Cucumber
(3) Pea
(4) Dianthus
Explanation: Cucumber has parietal placentation where ovules attach to ovary wall. Correct answer is (2).
3. Which feature distinguishes axile from parietal placentation?
(1) Number of ovules
(2) Location of ovules attachment
(3) Flower color
(4) Pollination type
Explanation: Axile has ovules attached to central axis; parietal attaches to ovary wall. Correct answer is (2).
4. Marginal placentation is characteristic of:
(1) Pea
(2) Tomato
(3) Dianthus
(4) Lemon
Explanation: Pea exhibits marginal placentation along ovary margin. Correct answer is (1).
5. A plant with compound ovary and central column of ovules has:
(1) Axile placentation
(2) Parietal placentation
(3) Free-central placentation
(4) Basal placentation
Explanation: Central column of ovules in compound ovary is axile placentation. Correct answer is (1).
6. In which family is axile placentation commonly found?
(1) Solanaceae
(2) Cucurbitaceae
(3) Brassicaceae
(4) Malvaceae
Explanation: Solanaceae (Tomato) commonly exhibits axile placentation. Correct answer is (1).
Assertion-Reason Type Question
7. Assertion (A): Dianthus exhibits axile placentation.
Reason (R): Ovules are attached to central axis of compound ovary.
(1) Both A and R true, R explains A
(2) Both A and R true, R does not explain A
(3) A true, R false
(4) A false, R true
Explanation: Axile placentation in Dianthus involves ovules attached to central axis; both statements are correct, and R explains A. Correct answer is (1).
Matching Type Question
8. Match plant with placentation type:
A. Tomato – (i) Parietal
B. Cucumber – (ii) Axile
C. Pea – (iii) Marginal
D. Dianthus – (iv) Axile
(1) A-(ii), B-(i), C-(iii), D-(iv)
(2) A-(iv), B-(ii), C-(i), D-(iii)
(3) A-(ii), B-(iii), C-(i), D-(iv)
(4) A-(ii), B-(i), C-(iii), D-(ii)
Explanation: Correct matches: Tomato-axile, Cucumber-parietal, Pea-marginal, Dianthus-axile. Correct answer is (1).
Fill in the Blanks Question
9. The ovules are attached to the central axis in ______ placentation.
(1) Axile
(2) Parietal
(3) Basal
(4) Free-central
Explanation: Ovules attached to central axis is characteristic of axile placentation. Correct answer is (1).
Choose the Correct Statements Question
10. Statement I: Tomato shows axile placentation.
Statement II: Axile placentation occurs in multi-loculed ovaries.
(1) I true, II false
(2) I false, II true
(3) Both true
(4) Both false
Explanation: Tomato has axile placentation; axile type occurs in multi-loculed compound ovaries. Both statements are correct. Correct answer is (3).
Keyword Definitions:
Tassel: The male inflorescence of maize/corn that produces pollen grains.
Pollen Grains: Male gametophytes that carry sperm cells for fertilization.
Corn Cob: The female inflorescence (ear) of maize containing ovules.
Pollination: Transfer of pollen from anther to stigma.
Monoecious Plant: Plant bearing both male and female flowers on the same individual.
Stigma: Part of pistil that receives pollen during pollination.
Fertilization: Fusion of male and female gametes to form zygote.
Wind Pollination: Pollination where pollen is dispersed by air currents.
Insect Pollination: Pollination facilitated by insects transferring pollen.
Ovule: Female reproductive structure that develops into seed after fertilization.
Inflorescence: Cluster of flowers arranged on a stem.
Lead Question - 2023:
What is the function of tassels in the corn cob?
(1) To disperse pollen grains
(2) To protect seeds
(3) To attract insects
(4) To trap pollen grains
Answer & Explanation: (1) To disperse pollen grains. Tassels are the male flowers of corn that produce and release pollen grains, which are carried by wind to the female flowers (silks) for fertilization. They do not protect seeds, attract insects, or trap pollen. This adaptation ensures efficient wind pollination in monoecious plants like maize, allowing successful reproduction. Tassels are positioned at the top of the plant, maximizing pollen dispersal distance. The structure and function of tassels are critical for crop yield, as inadequate pollen release can result in poor kernel formation, directly affecting productivity.
1. In maize, female flowers are called:
(1) Tassels
(2) Silks
(3) Stamens
(4) Anthers
Explanation: Female flowers in maize form the silks, which receive pollen from tassels for fertilization. Tassels are male flowers. Correct answer is (2).
2. Corn is classified as:
(1) Dioecious
(2) Monoecious
(3) Hermaphrodite
(4) Gynodioecious
Explanation: Corn is monoecious, bearing separate male (tassels) and female (silks) flowers on the same plant. Correct answer is (2).
3. The main mode of pollination in maize is:
(1) Insect-mediated
(2) Water-mediated
(3) Wind-mediated
(4) Self-pollination
Explanation: Maize relies on wind pollination (anemophily), with tassels dispersing pollen grains carried by air currents to silks. Correct answer is (3).
4. Each silk in maize is connected to:
(1) An individual ovule
(2) Multiple ovules
(3) A leaf
(4) A tassel
Explanation: Each silk corresponds to a single ovule in the ear, ensuring fertilization of one kernel per silk. Correct answer is (1).
5. Tassels are positioned:
(1) Below the ear
(2) At the tip of stem
(3) Inside silks
(4) Underground
Explanation: Tassels form at the top of the maize plant, enhancing pollen dispersal by wind to silks. Correct answer is (2).
6. The primary structure producing pollen in corn is:
(1) Stigma
(2) Tassel
(3) Silk
(4) Cob
Explanation: Tassels contain stamens that produce pollen grains necessary for fertilization. Correct answer is (2).
Assertion-Reason Type Question
7. Assertion (A): Tassels in corn release large amounts of pollen.
Reason (R): Wind pollination requires high pollen production for effective fertilization.
(1) Both A and R are true, and R is correct explanation of A
(2) Both A and R are true, but R is not correct explanation of A
(3) A is true, R is false
(4) A is false, R is true
Explanation: Tassels produce abundant pollen to compensate for randomness of wind pollination. Both assertion and reason are true, and R explains A. Correct answer is (1).
Matching Type Question
8. Match plant parts with function:
A. Tassel – (i) Female reproductive part
B. Silk – (ii) Male reproductive part
C. Cob – (iii) Supports ovules
D. Leaf – (iv) Photosynthesis
(1) A-(ii), B-(i), C-(iii), D-(iv)
(2) A-(i), B-(ii), C-(iv), D-(iii)
(3) A-(iii), B-(iv), C-(ii), D-(i)
(4) A-(iv), B-(iii), C-(i), D-(ii)
Explanation: Tassel is male (pollen producer), silk is female (receives pollen), cob supports ovules, and leaf performs photosynthesis. Correct answer is (1).
Fill in the Blanks Question
9. Tassels in corn primarily function to ________.
(1) Protect kernels
(2) Disperse pollen grains
(3) Attract insects
(4) Trap pollen
Explanation: Tassels produce and release pollen grains for fertilization of silks. Correct answer is (2).
Choose the Correct Statements Question
10. Statement I: Tassels are male flowers of maize.
Statement II: Silks are female flowers that receive pollen.
(1) Both statements are true
(2) Statement I true, Statement II false
(3) Statement I false, Statement II true
(4) Both statements are false
Explanation: Tassels are male inflorescences producing pollen, and silks are female flowers receiving pollen. Both statements are correct. Correct answer is (1).
Keyword Definitions:
Bat pollinated plants: Plants adapted to nocturnal pollination by bats, often with large, pale, fragrant flowers producing copious nectar.
Wind pollinated plants: Plants relying on wind for pollen transfer, usually small, inconspicuous flowers without nectar or fragrance.
Insect pollinated plants: Plants with flowers attracting insects using bright colors, scent, and nectar; pollen transfer is mediated by insect visits.
Bird pollinated plants: Flowers adapted for bird pollination, typically brightly colored (red/orange), tubular, and with abundant nectar.
Fragment flowers: Flowers that are conspicuous and showy, aiding in attracting pollinators.
Nectar: Sugar-rich liquid secreted by plants to attract pollinators.
Pollination: The transfer of pollen grains from anther to stigma for fertilization.
Lead Question - 2023:
Large, colourful, fragment flowers with nectar are seen in:
(1) Bat pollinated plants
(2) Wind pollinated plants
(3) Insect pollinated plants
(4) Bird pollinated plants
Answer & Explanation: (3) Insect pollinated plants. Insect-pollinated plants typically have large, brightly colored, fragrant flowers with nectar to attract insects such as bees, butterflies, and beetles. Wind-pollinated flowers are small and inconspicuous, lacking nectar or fragrance. Bat-pollinated flowers are usually pale and open at night, while bird-pollinated flowers are tubular, often red or orange, adapted to bird feeding. These floral adaptations maximize successful pollination by attracting specific pollinators. The presence of nectar and showy petals is a key feature for insect-mediated pollination, ensuring pollen transfer and reproductive success through frequent insect visits.
1. Which type of pollinated plants have inconspicuous flowers without nectar?
(1) Insect pollinated plants
(2) Wind pollinated plants
(3) Bird pollinated plants
(4) Bat pollinated plants
Explanation: Wind-pollinated plants produce small, non-fragrant, inconspicuous flowers without nectar. They rely on wind for pollen transfer rather than attracting pollinators. Hence, the correct answer is (2) Wind pollinated plants.
2. Bat-pollinated flowers are generally:
(1) Large, pale, night-blooming
(2) Small, inconspicuous
(3) Brightly colored and tubular
(4) Fragrant during the day
Explanation: Bat-pollinated flowers are adapted to nocturnal pollination, large, pale-colored, fragrant at night, and produce nectar to attract bats. They are distinct from insect- or bird-pollinated flowers. Correct answer is (1).
3. Bird-pollinated flowers are usually:
(1) White and nocturnal
(2) Brightly colored and tubular
(3) Inconspicuous
(4) Fragrant only at night
Explanation: Bird-pollinated flowers are bright, often red or orange, tubular, and produce nectar, attracting birds with long beaks. They differ from insect-pollinated flowers, which may be varied in color and scent. Correct answer is (2).
4. Nectar in flowers functions to:
(1) Attract pollinators
(2) Protect seeds
(3) Aid in photosynthesis
(4) Reduce herbivory
Explanation: Nectar is a sugar-rich secretion that attracts pollinators such as insects, birds, and bats. It does not protect seeds directly or aid photosynthesis. By attracting pollinators, it ensures effective pollen transfer. Correct answer is (1).
5. Fragment flowers are:
(1) Small and inconspicuous
(2) Large, showy, and attractive
(3) Only wind-pollinated
(4) Non-reproductive structures
Explanation: Fragment flowers are large, showy, and visually attractive to pollinators, ensuring effective pollination. They are typically insect- or bird-pollinated. Wind-pollinated flowers are small and inconspicuous. Correct answer is (2).
6. Insect-pollinated flowers attract pollinators using:
(1) Wind currents
(2) Color, scent, and nectar
(3) Water transport
(4) Gravity
Explanation: Insect-pollinated flowers use bright colors, fragrance, and nectar to attract insects, ensuring efficient pollen transfer. Wind or gravity is not involved in attraction. Correct answer is (2).
Assertion-Reason Type Question
7. Assertion (A): Large, colorful flowers are usually insect-pollinated.
Reason (R): Bright colors and nectar attract insects, aiding pollination.
(1) Both A and R are true, and R is correct explanation of A
(2) Both A and R are true, but R is not correct explanation
(3) A is true but R is false
(4) A is false but R is true
Explanation: Large, showy flowers are adapted to attract insects using bright colors and nectar. This ensures frequent insect visits for pollen transfer. Both statements are true, and R correctly explains A. Correct answer is (1).
Matching Type Question
8. Match flowers with their pollinators:
A. Red tubular flowers – (i) Birds
B. Large, fragrant night flowers – (ii) Bats
C. Small, inconspicuous flowers – (iii) Wind
D. Bright, nectariferous flowers – (iv) Insects
(1) A-(i), B-(ii), C-(iii), D-(iv)
(2) A-(ii), B-(iii), C-(i), D-(iv)
(3) A-(iv), B-(i), C-(ii), D-(iii)
(4) A-(iii), B-(iv), C-(i), D-(ii)
Explanation: Red tubular flowers attract birds, large night flowers attract bats, small inconspicuous flowers are wind-pollinated, and bright nectariferous flowers attract insects. Correct answer is (1).
Fill in the Blanks Question
9. Flowers producing nectar to attract insects are called ______ flowers.
(1) Wind-pollinated
(2) Insect-pollinated
(3) Bird-pollinated
(4) Bat-pollinated
Explanation: Insect-pollinated flowers produce nectar and are often large and colorful to attract insects. Wind-pollinated flowers lack nectar. Hence, the correct answer is (2) Insect-pollinated.
Choose the Correct Statements Question
10. Statement I: Wind-pollinated flowers are inconspicuous.
Statement II: Insect-pollinated flowers are large, colorful, and produce nectar.
(1) Both statements are true
(2) Statement I is true, Statement II is false
(3) Statement I is false, Statement II is true
(4) Both statements are false
Explanation: Wind-pollinated flowers are small and inconspicuous. Insect-pollinated flowers are large, colorful, and produce nectar to attract insects for effective pollination. Both statements are true. Correct answer is (1).
Keyword Definitions:
Fabaceae: A family of dicotyledonous plants, commonly called legumes, characterized by compound leaves and zygomorphic flowers.
Solanaceae: The nightshade family of plants with actinomorphic flowers and usually free or fused stamens.
Liliaceae: Monocot family with usually actinomorphic flowers, free stamens, and tepals.
Diadelphous Stamens: Stamens united by filaments into two bundles, typical of Fabaceae.
Dithecous Anthers: Anthers with two pollen sacs for pollen production.
Stamens: Male reproductive organs of flowers, consisting of filament and anther.
Lead Question - 2023:
Family Fabaceae differs from Solanaceae and Liliaceae. With respect to the stamens, pick out the characteristics specific to family Fabaceae but not found in Solanaceae or Liliaceae.
(1) Monoadelphous and Monothecous anthers
(2) Epiphyllous and Dithecous anthers
(3) Diadelphous and Dithecous anthers
(4) Polyadelphous and epipetalous stamens
Answer & Explanation: (3) Diadelphous and Dithecous anthers. In Fabaceae, stamens are typically diadelphous, meaning filaments are united in two bundles, one of nine stamens and the tenth free, forming a characteristic structure. Anthers are dithecous, each having two pollen sacs. This feature is absent in Solanaceae, which have epipetalous stamens, and Liliaceae, which have free, usually six stamens. Diadelphous stamens aid in specialized pollination mechanisms, and dithecous anthers ensure efficient pollen dispersal, making these features taxonomically significant for Fabaceae identification in comparative floral morphology studies.
1. The stamen arrangement in Liliaceae is usually:
(1) Diadelphous
(2) Free and equal
(3) Polyadelphous
(4) Monadelphous
Explanation: Liliaceae, being monocots, typically have six free stamens, equally arranged, without fusion. This contrasts with Fabaceae's diadelphous condition. Free stamens allow generalized pollination mechanisms. Hence, the correct answer is (2) Free and equal.
2. In Solanaceae, stamens are usually:
(1) Diadelphous
(2) Epipetalous
(3) Monadelphous
(4) Free and monothecous
Explanation: In Solanaceae, stamens are epipetalous, meaning their filaments are attached to petals, unlike Fabaceae where filaments are partially fused into two bundles. Epipetalous stamens facilitate pollen deposition on visiting pollinators. Hence, the correct answer is (2) Epipetalous.
3. The term dithecous refers to:
(1) Two stamens
(2) Anthers with two pollen sacs
(3) Fusion of stamens
(4) Single pollen sac
Explanation: Dithecous anthers have two pollen sacs (microsporangia) for pollen production, a common feature in Fabaceae. This ensures efficient pollen release. Monothecous anthers have one pollen sac. Hence, the correct answer is (2) Anthers with two pollen sacs.
4. Diadelphous stamen arrangement means:
(1) All filaments free
(2) All filaments united into a single bundle
(3) Filaments united in two groups
(4) Filaments united in more than two bundles
Explanation: In diadelphous condition, stamens’ filaments are united in two bundles, usually nine fused and one free in Fabaceae flowers. This aids in proper pollen transfer to pollinators. Hence, the correct answer is (3) Filaments united in two groups.
5. Which type of stamen arrangement is typical in Fabaceae?
(1) Monadelphous
(2) Polyadelphous
(3) Diadelphous
(4) Epiphyllous
Explanation: Fabaceae flowers show diadelphous stamens, where filaments are united into two bundles, an adaptation for specialized pollination and flower mechanics. Other families like Liliaceae and Solanaceae lack this condition. Hence, the correct answer is (3) Diadelphous.
6. Polyadelphous stamens are characteristic of:
(1) Fabaceae
(2) Malvaceae
(3) Solanaceae
(4) Liliaceae
Explanation: Polyadelphous stamens have filaments united in more than two bundles, a feature of Malvaceae. Fabaceae typically show diadelphous stamens. Polyadelphous arrangement aids in coordinated pollen release. Hence, the correct answer is (2) Malvaceae.
Assertion-Reason Type Question
7. Assertion (A): Fabaceae stamens are diadelphous and dithecous.
Reason (R): This stamen arrangement facilitates specialized pollination and efficient pollen transfer.
(1) Both A and R are true, and R is the correct explanation of A.
(2) Both A and R are true, but R is not the correct explanation of A.
(3) A is true but R is false.
(4) A is false but R is true.
Explanation: Diadelphous stamens in Fabaceae aid in forming a keel structure that directs pollinators. Dithecous anthers ensure efficient pollen dispersal. Both statements are true and R correctly explains A. Hence, the correct answer is (1).
Matching Type Question
8. Match the following:
A. Fabaceae – (i) Polyadelphous
B. Malvaceae – (ii) Diadelphous
C. Solanaceae – (iii) Epipetalous
(1) A-(ii), B-(i), C-(iii)
(2) A-(i), B-(ii), C-(iii)
(3) A-(iii), B-(ii), C-(i)
(4) A-(ii), B-(iii), C-(i)
Explanation: Fabaceae has diadelphous stamens, Malvaceae shows polyadelphous stamens, and Solanaceae has epipetalous stamens. Correct matching is A-(ii), B-(i), C-(iii). Hence, the answer is (1).
Fill in the Blanks Question
9. In Fabaceae flowers, each anther has ______ pollen sacs.
(1) One
(2) Two
(3) Three
(4) Four
Explanation: Fabaceae anthers are dithecous, meaning each anther has two pollen sacs. This ensures adequate pollen production and efficient pollination. Hence, the correct answer is (2) Two.
Choose the Correct Statements Question
10. Statement I: Fabaceae stamens are diadelphous.
Statement II: Solanaceae stamens are epipetalous.
(1) Both statements are true.
(2) Statement I is true, Statement II is false.
(3) Statement I is false, Statement II is true.
(4) Both statements are false.
Explanation: Fabaceae shows diadelphous stamens for specialized pollination, whereas Solanaceae has stamens attached to petals (epipetalous). Both statements correctly describe stamen arrangements in respective families. Hence, the correct answer is (1) Both statements are true.
Keyword Definitions:
Embryo Sac: The female gametophyte of angiosperms formed from the megaspore after meiosis.
Synergids: Two specialized cells near the egg cell aiding in pollen tube entry.
Zygote: The diploid cell formed after fusion of male and female gametes.
Primary Endosperm Nucleus: A triploid nucleus formed by fusion of two polar nuclei and one sperm nucleus.
Double Fertilization: Process involving fusion of one male gamete with egg cell and another with polar nuclei.
Lead Question (2023): In angiosperm the haploid, diploid and triploid structures of a fertilized embryo sac sequentially are:
(1) Synergids, Zygote and Primary endosperm nucleus
(2) Synergids, antipodals and polar nuclei
(3) Synergids, antipodals and polar nuclei and zygote
(4) Antipodals, synergids and primary endosperm nucleus
Answer & Explanation: (1) Synergids, Zygote and Primary endosperm nucleus.
In a fertilized embryo sac, synergids are haploid structures, the zygote is diploid, and the primary endosperm nucleus is triploid. This sequence represents the outcome of double fertilization in angiosperms. The triploid endosperm provides nourishment to the developing embryo formed from the diploid zygote after fertilization.
Guessed Questions:
1. Which part of the embryo sac is responsible for guiding the pollen tube towards the egg cell?
(1) Antipodals
(2) Synergids
(3) Polar nuclei
(4) Egg apparatus
Answer & Explanation: (2) Synergids. Synergids secrete attractants that guide the pollen tube to the egg cell for fertilization. They degenerate after pollen tube discharge, ensuring proper gamete release. Their filiform apparatus aids in nutrient transfer to the egg, maintaining embryo sac functionality during fertilization and double fertilization events in angiosperms.
2. The fusion of one male gamete with two polar nuclei is known as:
(1) Syngamy
(2) Triple fusion
(3) Autogamy
(4) Cross-pollination
Answer & Explanation: (2) Triple fusion. Triple fusion occurs when one male gamete fuses with the two polar nuclei, forming a triploid primary endosperm nucleus. This process, along with syngamy, constitutes double fertilization in flowering plants, a unique feature of angiosperms that ensures endosperm development for embryo nourishment.
3. The ploidy of the antipodal cells in a typical embryo sac is:
(1) Diploid
(2) Haploid
(3) Triploid
(4) Tetraploid
Answer & Explanation: (2) Haploid. Antipodal cells are haploid and located at the chalazal end of the embryo sac. They originate from the functional megaspore through mitotic divisions. Though their exact role is uncertain, they are believed to nourish the embryo sac and support the fertilization process indirectly in angiosperms.
4. Which structure of the embryo sac directly develops into the endosperm after fertilization?
(1) Polar nuclei
(2) Egg cell
(3) Synergids
(4) Antipodals
Answer & Explanation: (1) Polar nuclei. During double fertilization, one sperm fuses with the polar nuclei forming the primary endosperm nucleus. This triploid structure divides repeatedly to form the endosperm, which nourishes the developing embryo. The endosperm thus provides essential nutrients for proper embryonic growth and seed development.
5. Which event in angiosperms ensures the development of both zygote and endosperm simultaneously?
(1) Pollination
(2) Syngamy
(3) Double fertilization
(4) Embryogenesis
Answer & Explanation: (3) Double fertilization. In angiosperms, one male gamete fuses with the egg cell forming a zygote, and the other with two polar nuclei forming the endosperm. This synchronized event ensures balanced development of embryo and endosperm, providing the necessary resources for the young seed to mature effectively.
6. Which of the following is triploid in an angiosperm embryo sac after fertilization?
(1) Egg cell
(2) Zygote
(3) Primary endosperm nucleus
(4) Antipodal cell
Answer & Explanation: (3) Primary endosperm nucleus. The fusion of two haploid polar nuclei with one haploid male nucleus forms the triploid primary endosperm nucleus. This triploid tissue later develops into endosperm, which supports the embryo nutritionally during seed development and germination phases in flowering plants.
7. Assertion-Reason Type:
Assertion (A): The endosperm of angiosperms is triploid.
Reason (R): It results from fusion of one male gamete with two polar nuclei.
(1) Both A and R are true, and R is the correct explanation of A
(2) Both A and R are true, but R is not the correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Answer & Explanation: (1) Both A and R are true, and R is the correct explanation of A. In angiosperms, the fusion of a sperm nucleus with two polar nuclei produces a triploid endosperm nucleus. This nutritive tissue supports embryo growth and differentiates angiosperms from gymnosperms that lack double fertilization.
8. Matching Type Question:
Match the following structures with their ploidy level:
A. Zygote
B. Synergid
C. Primary Endosperm Nucleus
D. Antipodal cell
(1) A–2n, B–n, C–3n, D–n
(2) A–n, B–2n, C–3n, D–n
(3) A–2n, B–n, C–2n, D–3n
(4) A–n, B–n, C–2n, D–3n
Answer & Explanation: (1) A–2n, B–n, C–3n, D–n. In angiosperms, zygote is diploid (2n), synergid and antipodal cells are haploid (n), while the primary endosperm nucleus is triploid (3n). These ploidy levels arise from gametic and nuclear fusions during the double fertilization process unique to flowering plants.
9. Fill in the Blanks:
The fusion of two gametes of dissimilar size is known as __________.
(1) Autogamy
(2) Isogamy
(3) Anisogamy
(4) Syngamy
Answer & Explanation: (3) Anisogamy. Anisogamy refers to fusion between morphologically or functionally dissimilar gametes, typically one large non-motile (egg) and one small motile (sperm) cell. In higher plants, fertilization involves such gametes, leading to zygote formation, and this evolutionary strategy ensures effective genetic variation and reproductive success.
10. Choose the Correct Statements (Statement I & II):
Statement I: In angiosperms, the endosperm is formed before embryo development.
Statement II: The primary endosperm nucleus is diploid.
(1) Both statements are correct
(2) Both statements are incorrect
(3) Statement I is correct, Statement II is incorrect
(4) Statement I is incorrect, Statement II is correct
Answer & Explanation: (3) Statement I is correct, Statement II is incorrect. Endosperm formation precedes embryo development to provide nutrients. However, the primary endosperm nucleus is triploid, not diploid. Its early formation ensures metabolic support for embryogenesis and seed maturation, which are vital stages of angiosperm reproduction.
Topic: Apomixis and Hybrid Crops; Subtopic: Genetic Engineering in Crop Improvement
Keyword Definitions:
• Apomixis: Asexual reproduction through seeds without fertilization, producing offspring genetically identical to the parent.
• Hybrid Varieties: Plants produced by crossing genetically distinct parents, showing heterosis or hybrid vigor.
• Polyembryony: Formation of multiple embryos from a single fertilized egg or ovule, can be natural or induced.
• Dormancy: Period in which seeds do not germinate despite favorable conditions.
• Segregation: Separation of alleles during gamete formation, leading to variation in progeny.
• Genetic Engineering: Manipulation of DNA to introduce desired traits into organisms.
• Crop Improvement: Enhancing yield, quality, or stress tolerance in cultivated plants.
• Clonal Propagation: Asexual reproduction producing genetically identical plants.
• Seed Saving: Farmers reusing seeds from previous harvests to grow new crops.
• Heterosis: Hybrid vigor showing superior traits compared to parents.
• Progeny: Offspring resulting from reproduction, sexually or asexually.
Lead Question - 2022 (Ganganagar)
Which of the following can be expected if scientists succeed in introducing apomictic gene into hybrid varieties of crops?
1. Polyembryony will be seen and each seed will produce many plantlets
2. Seeds of hybrid plants will show longer dormancy
3. Farmers can keep on using the seeds produced by the hybrids to raise new crop year after year
4. There will be segregation of the desired characters only in the progeny
Explanation: Introducing the apomictic gene in hybrid crops allows asexual reproduction through seeds, producing offspring genetically identical to the parent. This ensures that hybrid vigor is maintained and farmers can reuse seeds to grow successive crops without losing traits. Polyembryony is not necessarily induced in all cases, dormancy is not significantly affected, and no segregation occurs because meiosis is bypassed. Therefore, the expected outcome is that farmers can continually use hybrid seeds with stable traits. Correct answer is 3. This approach is significant for crop improvement and sustainable agriculture.
1. Single Correct Answer MCQ:
Apomixis in plants primarily results in:
a) Increased segregation of traits
b) Offspring genetically identical to parent
c) Formation of hybrids
d) Longer seed dormancy
Explanation: Apomixis bypasses fertilization, producing clonal seeds genetically identical to the parent plant. No segregation occurs, and hybrid traits are maintained. Correct answer is b) Offspring genetically identical to parent.
2. Single Correct Answer MCQ:
The main benefit of apomixis in hybrid crops is:
a) Greater genetic variability
b) Maintaining hybrid vigor in progeny
c) Increased seed dormancy
d) Inducing polyembryony in all seeds
Explanation: Apomixis preserves the superior traits of hybrids across generations by producing genetically identical seeds. Variability and polyembryony are not primary outcomes. Correct answer is b) Maintaining hybrid vigor in progeny.
3. Single Correct Answer MCQ:
Which process is bypassed in apomictic reproduction?
a) Pollination
b) Fertilization
c) Seed germination
d) Photosynthesis
Explanation: Fertilization is bypassed in apomixis, allowing seed formation without gamete fusion. Pollination is irrelevant, germination and photosynthesis continue normally. Correct answer is b) Fertilization.
4. Single Correct Answer MCQ:
Seeds produced by apomictic hybrid crops can be:
a) Used only once
b) Reused for multiple generations
c) Segregating for traits
d) Less viable than sexual seeds
Explanation: Apomictic seeds maintain hybrid traits, allowing farmers to reuse seeds over multiple seasons without loss of desired characteristics. Correct answer is b) Reused for multiple generations.
5. Single Correct Answer MCQ:
Polyembryony in apomixis leads to:
a) Increased genetic variability
b) Multiple plantlets from a single seed
c) Seed dormancy
d) Segregation of traits
Explanation: Polyembryony can result in multiple embryos developing in a seed, potentially forming several genetically identical plantlets. Correct answer is b) Multiple plantlets from a single seed.
6. Single Correct Answer MCQ:
Which statement is false regarding apomictic hybrid crops?
a) Offspring are clones of the parent
b) Desired traits are preserved
c) Segregation occurs normally
d) Farmers can reuse seeds
Explanation: Segregation does not occur in apomictic reproduction as meiosis is bypassed; offspring are genetically identical to parent, preserving hybrid traits. Correct answer is c) Segregation occurs normally.
7. Assertion-Reason MCQ:
Assertion (A): Apomixis allows farmers to reuse hybrid seeds.
Reason (R): Apomixis produces offspring genetically identical to parent, maintaining hybrid vigor.
a) Both A and R are true, R explains A
b) Both A and R are true, R does not explain A
c) A is true, R is false
d) A is false, R is true
Explanation: Apomixis produces clonal seeds preserving hybrid traits, enabling repeated seed usage. Both the assertion and reason are true, and the reason correctly explains the assertion. Correct answer is a) Both A and R are true, R explains A.
8. Matching Type MCQ:
Match the term with its definition:
Column I | Column II
A) Apomixis | 1) Bypasses fertilization to form seeds
B) Polyembryony | 2) Multiple embryos in a single seed
C) Hybrid vigor | 3) Superior traits in hybrid offspring
D) Segregation | 4) Separation of alleles during gamete formation
Choices: A-__ B-__ C-__ D-__
Explanation: A-1 (Apomixis bypasses fertilization), B-2 (Polyembryony forms multiple embryos), C-3 (Hybrid vigor expresses superior traits), D-4 (Segregation is separation of alleles). Correct matching demonstrates key concepts in plant breeding and apomixis.
9. Fill in the Blanks / Completion MCQ:
Apomictic reproduction in hybrid crops results in ______ of hybrid traits.
a) Segregation
b) Preservation
c) Loss
d) Mutation
Explanation: Apomixis maintains genetic identity, preserving hybrid traits in successive generations. Correct answer is b) Preservation.
10. Choose the correct statements MCQ (Statement I & II):
Statement I: Apomictic hybrid seeds allow continuous cultivation without loss of hybrid vigor.
Statement II: Apomixis increases segregation of desired traits.
a) Both I and II are correct
b) Only I is correct
c) Only II is correct
d) Both are incorrect
Explanation: Apomixis preserves hybrid traits allowing repeated use of seeds (Statement I correct). It bypasses meiosis, so no segregation occurs (Statement II incorrect). Correct answer is b) Only I is correct.
Chapter: Reproduction in Flowering Plants; Topic: Seed Structure and Development; Subtopic: Perisperm and Nutritive Tissue in Seeds
Keyword Definitions:
• Perisperm: Nutritive tissue derived from the nucellus that persists in some seeds, supporting embryo development.
• Nucellus: Central part of the ovule surrounding the embryo sac, providing nutrition.
• Endosperm: Triploid tissue formed after double fertilization, serving as nutrient source in seeds.
• Calyx: Outer whorl of sepals protecting the flower bud.
• Integument: Protective layer enclosing the nucellus in an ovule, forming seed coat after fertilization.
• Embryo: Young sporophyte in seed formed after fertilization.
• Seed coat: Protective covering of a seed derived from integuments.
• Fertilization: Fusion of male and female gametes in ovule.
• Residual tissue: Tissue remaining after development of seed structures.
• Beet seed: Example of perispermous seed where nucellus persists.
• Nutritive tissue: Tissue supplying nutrients to developing embryo and endosperm.
Lead Question - 2022 (Ganganagar)
The residual persistent part which forms the perisperm in the seeds of beet is:
1. Calyx
2. Endosperm
3. Nucellus
4. Integument
Explanation: In beet seeds, the nucellus does not completely degenerate during seed development. Instead, the residual nucellus persists as a nutritive tissue called perisperm, providing nourishment to the developing embryo. Endosperm may also be present in some species, but the perisperm is specifically derived from nucellus, not from integuments or calyx. This structural adaptation ensures sufficient nutrient supply for embryo growth, particularly in seeds where endosperm is reduced or absent. Therefore, the correct answer is 3. Nucellus. Understanding perisperm formation is crucial in seed anatomy and development studies, highlighting the diverse sources of nutritive tissue in angiosperms.
1. Single Correct Answer MCQ:
Which tissue forms the perisperm in seeds?
a) Integument
b) Nucellus
c) Endosperm
d) Seed coat
Explanation: The perisperm originates from the nucellus, the central part of ovule, and remains persistent in certain seeds to nourish the embryo. Integuments form seed coat, endosperm is separate triploid tissue, and seed coat protects the seed. Correct answer is b) Nucellus.
2. Single Correct Answer MCQ:
Endosperm in angiosperm seeds is formed by:
a) Fusion of two polar nuclei with one male gamete
b) Fusion of male and female gametes
c) Nucellus persistence
d) Seed coat development
Explanation: Endosperm arises after double fertilization: one male gamete fuses with two polar nuclei in the embryo sac, forming triploid endosperm. Nucellus persistence forms perisperm, not endosperm. Correct answer is a) Fusion of two polar nuclei with one male gamete.
3. Single Correct Answer MCQ:
The perisperm is absent in seeds of:
a) Beet
b) Coconut
c) Groundnut
d) Maize
Explanation: Coconut has perisperm, beet has perisperm, groundnut and maize do not; they rely mainly on endosperm for embryo nourishment. Perisperm is characteristic of certain seeds where nucellus persists. Correct answer is d) Maize.
4. Single Correct Answer MCQ:
Residual nucellus in seed acts as:
a) Protective layer
b) Nutritive tissue
c) Fertilizing agent
d) Water storage tissue
Explanation: The persistent nucellus provides nutrients to the developing embryo, functioning as perisperm. It does not protect, fertilize, or primarily store water. Correct answer is b) Nutritive tissue.
5. Single Correct Answer MCQ:
Which of the following is a perispermous seed?
a) Wheat
b) Beet
c) Maize
d) Mustard
Explanation: Beet seeds retain residual nucellus as perisperm. Wheat, maize, and mustard have endospermic seeds with little or no perisperm. Correct answer is b) Beet.
6. Single Correct Answer MCQ:
Calyx contributes to:
a) Perisperm
b) Seed coat
c) Flower protection
d) Embryo nutrition
Explanation: Calyx comprises sepals that protect flower buds. It does not form perisperm, seed coat, or nourish embryo. Correct answer is c) Flower protection.
7. Assertion-Reason MCQ:
Assertion (A): Perisperm in beet is derived from nucellus.
Reason (R): Nucellus persists after fertilization to provide nourishment.
a) Both A and R are true, R explains A
b) Both A and R are true, R does not explain A
c) A is true, R is false
d) A is false, R is true
Explanation: The residual nucellus remains after fertilization and forms perisperm to nourish the embryo. Both assertion and reason are correct, with reason explaining the assertion. Correct answer is a) Both A and R are true, R explains A.
8. Matching Type MCQ:
Match seed type with tissue providing nutrition:
Column I
A) Perispermous
B) Endospermic
C) Non-endospermic
D) Coconut
Column II
1) Nucellus
2) Endosperm
3) Cotyledons
4) Both perisperm and endosperm
Choices:
A-__ B-__ C-__ D-__
Explanation: Perispermous: nucellus (A-1), Endospermic: endosperm (B-2), Non-endospermic: cotyledons (C-3), Coconut: perisperm and endosperm (D-4). Correct matches: A-1, B-2, C-3, D-4.
9. Fill in the Blanks / Completion MCQ:
The tissue forming perisperm in seeds is __________.
a) Endosperm
b) Nucellus
c) Integument
d) Cotyledon
Explanation: Perisperm is derived from nucellus, which persists as a nutritive tissue for embryo. Endosperm is separate, integument forms seed coat, cotyledons store food. Correct answer is b) Nucellus.
10. Choose the correct statements MCQ (Statement I & II):
Statement I: Nucellus may persist as perisperm in certain seeds.
Statement II: Endosperm is always derived from nucellus.
a) Both I and II are correct
b) Only I is correct
c) Only II is correct
d) Both are incorrect
Explanation: Nucellus can persist as perisperm, supplying nutrients. Endosperm forms via double fertilization, not from nucellus. Statement I is correct, Statement II is false. Correct answer is b) Only I is correct.
Topic: Floral Parts and Aestivation; Subtopic: Types of Aestivation and Examples
Keyword Definitions:
• Aestivation: Arrangement of sepals or petals in a floral bud before it opens.
• Imbricate: Overlapping petals, where some overlap and some are overlapped (e.g., Cassia).
• Valvate: Petals just touch each other without overlapping (e.g., Calotropis).
• Vexillary: Standard petal covers wings and keel (e.g., Bean).
• Twisted: Each petal overlaps the next one in regular order (e.g., Cotton).
Lead Question – 2022 (Ganganagar)
Match List-I with List-II
List-I List-II
(a) Imbricate (i) Calotropis
(b) Valvate (ii) Cassia
(c) Vexillary (iii) Cotton
(d) Twisted (iv) Bean
Choose the correct answer from the options given below:
(a) (b) (c) (d)
1. (ii) (i) (iii) (iv)
2. (ii) (i) (iv) (iii)
3. (ii) (iv) (iii) (i)
4. (i) (iii) (iv) (ii)
Explanation: The correct answer is option 2. Imbricate aestivation occurs in Cassia, valvate in Calotropis, vexillary in Bean, and twisted in Cotton. These patterns describe how petals or sepals are arranged before blooming. Such arrangements help in identification of plant families and are taxonomically important.
Guessed Questions:
1. (Single Correct Answer)
Which type of aestivation is found in China rose?
1. Imbricate
2. Valvate
3. Twisted
4. Vexillary
Explanation: The correct answer is option 3. In China rose (Hibiscus), petals are arranged so that each overlaps the next, forming a regular twisted pattern. This twisted aestivation aids in identifying members of the Malvaceae family and is a key floral characteristic in their classification.
2. (Single Correct Answer)
In which of the following plants valvate aestivation is found?
1. Calotropis
2. Cassia
3. Pea
4. Cotton
Explanation: The correct answer is option 1. Calotropis shows valvate aestivation where petals or sepals just touch each other at the margins without overlapping. This arrangement provides a symmetrical flower appearance, often associated with members of the Asclepiadaceae family.
3. (Single Correct Answer)
Vexillary aestivation is a characteristic feature of which family?
1. Malvaceae
2. Fabaceae
3. Solanaceae
4. Brassicaceae
Explanation: The correct answer is option 2. Vexillary aestivation is typical of the Fabaceae family, where the largest petal (standard) covers the lateral wings and keel. This specialized arrangement helps in pollination and provides protection to reproductive organs inside the corolla.
4. (Single Correct Answer)
Which of the following correctly matches flower and aestivation?
1. Cotton – Imbricate
2. Bean – Valvate
3. Cassia – Imbricate
4. Calotropis – Twisted
Explanation: The correct answer is option 3. Cassia exhibits imbricate aestivation where petals overlap irregularly. This feature helps identify members of the Caesalpinioideae subfamily and aids in differentiating them from others showing valvate or twisted arrangements.
5. (Single Correct Answer)
Which type of aestivation shows all petals touching but not overlapping?
1. Twisted
2. Valvate
3. Imbricate
4. Vexillary
Explanation: The correct answer is option 2. Valvate aestivation is where sepals or petals are arranged edge to edge without overlapping. It is commonly seen in Calotropis. This simple floral arrangement contributes to easy floral dissection and family identification.
6. (Single Correct Answer)
Twisted aestivation occurs in which of the following plants?
1. China rose
2. Mustard
3. Pea
4. Cassia
Explanation: The correct answer is option 1. China rose, a member of Malvaceae, shows twisted aestivation where each petal overlaps the next one in a fixed direction. This regular overlapping is characteristic of hibiscus flowers and aids in identifying this family morphologically.
7. (Assertion–Reason)
Assertion (A): Vexillary aestivation is characteristic of Papilionaceous flowers.
Reason (R): In such flowers, standard petal overlaps wings, and wings overlap keel.
1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, but R is true.
Explanation: The correct answer is option 1. Both A and R are true, and R correctly explains A. Vexillary aestivation is seen in Papilionaceous flowers like peas and beans where the large standard petal overlaps wings and keel in a specific arrangement aiding in pollination.
8. (Matching Type)
Match the following:
A. Valvate — 1. Hibiscus
B. Twisted — 2. Calotropis
C. Imbricate — 3. Cassia
D. Vexillary — 4. Pea
1. A–2, B–1, C–3, D–4
2. A–3, B–2, C–4, D–1
3. A–1, B–3, C–4, D–2
4. A–4, B–2, C–1, D–3
Explanation: The correct answer is option 1. Valvate – Calotropis, Twisted – Hibiscus, Imbricate – Cassia, and Vexillary – Pea. This matching illustrates how floral aestivation varies among families and assists in their identification during plant taxonomy classification.
9. (Fill in the Blanks)
In _______ aestivation, the margins of petals overlap one another in a definite direction, as in China rose.
Options:
1. Valvate
2. Twisted
3. Imbricate
4. Vexillary
Explanation: The correct answer is option 2. Twisted aestivation involves each petal overlapping the next one consistently. This is common in Malvaceae (e.g., Hibiscus) and provides a spiral floral pattern that helps botanists identify related species through morphological study.
10. (Choose the Correct Statements)
Statement I: Imbricate aestivation is seen in Calotropis.
Statement II: Vexillary aestivation is found in Pea.
1. Both statements are correct.
2. Both statements are incorrect.
3. Only Statement I is correct.
4. Only Statement II is correct.
Explanation: The correct answer is option 4. Only Statement II is correct. Pea exhibits vexillary aestivation characteristic of Papilionaceae, whereas Calotropis shows valvate aestivation. Correct identification of aestivation helps in understanding floral morphology and taxonomic classification.
Chapter: Sexual Reproduction in Flowering Plants; Topic: Embryo Sac Structure; Subtopic: Egg Apparatus and Female Gametophyte Organization
Keyword Definitions:
Embryo sac: The female gametophyte of an angiosperm, usually 7-celled and 8-nucleate, formed from the megaspore.
Egg apparatus: A group of three cells at the micropylar end of the embryo sac, consisting of one egg cell and two synergids.
Synergids: Two cells that help in guiding the pollen tube to the egg cell for fertilization.
Antipodal cells: Three cells at the chalazal end of the embryo sac, with a nutritive role.
Polar nuclei: Two nuclei in the center that fuse with a male gamete to form the triploid endosperm nucleus.
Lead Question - 2022 (Ganganagar)
In general the egg apparatus of embryo sac in angiosperm consists of :
1. One egg cell, two synergids, three antipodal cells, two polar nuclei
2. One egg cell, two synergids, two antipodal cells, three polar nuclei
3. One egg cell, three synergids, two antipodal cells, two polar nuclei
4. One egg cell, two synergids, two antipodal cells, two polar nuclei
Explanation: In most flowering plants, the mature embryo sac (female gametophyte) is 7-celled and 8-nucleate. It includes one egg cell and two synergids forming the egg apparatus at the micropylar end, three antipodal cells at the chalazal end, and two polar nuclei in the center. This is the Polygonum type of embryo sac. (Answer: One egg cell, two synergids, three antipodal cells, two polar nuclei)
1. The mature embryo sac of angiosperms generally develops from:
1. Megasporangium
2. Megaspore
3. Ovule
4. Nucellus
Explanation: The mature embryo sac develops from a functional haploid megaspore after three mitotic divisions. Out of four megaspores formed by meiosis, one remains functional while the rest degenerate. (Answer: Megaspore)
2. The type of embryo sac commonly found in angiosperms is:
1. Monosporic
2. Bisporic
3. Tetrasporic
4. Polyspermic
Explanation: The most common type of embryo sac in angiosperms is the monosporic type (Polygonum type), which develops from a single functional megaspore. It undergoes three mitotic divisions to form 8 nuclei arranged in seven cells. (Answer: Monosporic)
3. The function of synergids in the embryo sac is to:
1. Nourish the embryo
2. Guide the pollen tube towards the egg cell
3. Form endosperm
4. Protect antipodal cells
Explanation: The synergids play an essential role in pollen tube guidance and reception. They secrete chemical attractants like LURE peptides that direct the pollen tube to the egg cell, ensuring successful fertilization. (Answer: Guide the pollen tube towards the egg cell)
4. The number of nuclei in a mature embryo sac is:
1. 6
2. 7
3. 8
4. 9
Explanation: A mature embryo sac is 7-celled but contains 8 nuclei. It has one egg cell, two synergids, three antipodal cells, and two polar nuclei in the central cell. These nuclei play key roles in double fertilization. (Answer: 8)
5. Double fertilization is a characteristic feature of:
1. Gymnosperms
2. Bryophytes
3. Angiosperms
4. Pteridophytes
Explanation: Double fertilization occurs only in angiosperms. One male gamete fuses with the egg to form a diploid zygote, while the other fuses with two polar nuclei to form the triploid primary endosperm nucleus. (Answer: Angiosperms)
6. The antipodal cells in the embryo sac generally:
1. Degenerate after fertilization
2. Fuse with male gamete
3. Develop into embryo
4. Form endosperm
Explanation: Antipodal cells are located at the chalazal end of the embryo sac and usually degenerate after fertilization. They may provide nourishment to the developing embryo sac before disintegration. (Answer: Degenerate after fertilization)
7. Assertion-Reason Question
Assertion (A): The embryo sac in most angiosperms is 7-celled and 8-nucleate.
Reason (R): It is formed by three mitotic divisions of one functional megaspore.
1. Both A and R are true, and R is the correct explanation of A
2. Both A and R are true, but R is not the correct explanation of A
3. A is true but R is false
4. A is false but R is true
Explanation: The Polygonum type embryo sac develops from a single haploid megaspore by three mitotic divisions, producing eight nuclei in seven cells. Hence, both A and R are true, and R correctly explains A. (Answer: Option 1)
8. Matching Type Question
Match the following structures with their positions in the embryo sac:
List-I — Structure
(a) Egg cell
(b) Synergids
(c) Polar nuclei
(d) Antipodals
List-II — Position
(i) Central cell
(ii) Micropylar end
(iii) Chalazal end
(iv) Micropylar end
1. (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii)
2. (a)-(iii), (b)-(ii), (c)-(iv), (d)-(i)
3. (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)
4. (a)-(iv), (b)-(ii), (c)-(iii), (d)-(i)
Explanation: The egg cell and synergids are present at the micropylar end, polar nuclei in the center, and antipodals at the chalazal end. The correct match is (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii). (Answer: Option 1)
9. Fill in the Blanks Question
The embryo sac of angiosperms is derived from __________ megaspore.
1. All four
2. Any one
3. The functional
4. The degenerated
Explanation: Only one functional megaspore out of four produced during megasporogenesis develops into the embryo sac, while the other three degenerate. (Answer: The functional)
10. Choose the Correct Statements
Statement I: The egg apparatus consists of one egg cell and two synergids.
Statement II: The antipodal cells lie at the micropylar end.
1. Both statements are correct
2. Both statements are incorrect
3. Statement I is correct, Statement II is incorrect
4. Statement I is incorrect, Statement II is correct
Explanation: Statement I is correct as the egg apparatus comprises one egg and two synergids at the micropylar end. Statement II is incorrect because antipodal cells are located at the chalazal end. (Answer: Statement I is correct, Statement II is incorrect)
Topic: Vegetative Propagation; Subtopic: Asexual Reproduction
Keyword Definitions:
Vegetative Propagule: A plant part capable of giving rise to a new individual, used in asexual reproduction.
Eyes of Potato: Buds on the tuber capable of sprouting new plants.
Rhizome of Ginger: Underground horizontal stem that can develop into a new plant.
Bulbil of Agave: Small bulb-like structures on the plant that can grow into a new plant.
Zoospore: Motile spore produced by some algae for asexual reproduction but not a vegetative propagule.
Buds in Hydra: Formed by asexual reproduction in animals and not a plant vegetative propagule.
Lead Question - 2022 (Abroad)
Which of the following is/are vegetative propagule(s)?
(a) Eyes of Potato
(b) Zoospore of Chlamydomonas
(c) Rhizome of Ginger
(d) Buds in Hydra
(e) Bulbil of Agave
Choose the most appropriate answer from the options given below:
1. (e) only
2. (a), (c), (e) only
3. (a), (b), (c), (d) only
4. (b), (d) only
Explanation: The correct answer is (a), (c), (e) only. Vegetative propagules are plant parts that develop into a new individual asexually. Eyes of potato, rhizome of ginger, and bulbil of agave are classic vegetative propagules. Zoospores of Chlamydomonas are asexual reproductive spores, not vegetative propagules, and buds in Hydra are animal-based asexual reproduction. These vegetative structures allow rapid multiplication and preservation of plant traits without sexual reproduction, which is especially useful in agriculture and horticulture for uniform crop production and propagation of desirable varieties.
1. Single Correct Answer Type:
Which of the following is an underground vegetative propagule?
1. Bulbil of Agave
2. Rhizome of Ginger
3. Eyes of Potato
4. Zoospore of Chlamydomonas
Explanation: The correct answer is Rhizome of Ginger. Rhizomes are underground horizontal stems that can produce new shoots and roots, forming new plants. They are vegetative propagules used in asexual reproduction. Unlike bulbs or eyes of potato which are modified stems or buds, rhizomes spread underground and store nutrients, facilitating propagation and survival during unfavorable conditions, making them highly efficient for vegetative multiplication.
2. Single Correct Answer Type:
Which propagule is used for asexual propagation in potato?
1. Bulbil
2. Rhizome
3. Eyes of Potato
4. Zoospore
Explanation: The correct answer is Eyes of Potato. Eyes are dormant buds present on potato tubers capable of sprouting into new plants. They serve as vegetative propagules for asexual reproduction. Planting tubers with healthy eyes ensures rapid multiplication and uniform growth of crops, preserving parental traits. Unlike zoospores or rhizomes, these structures are modified stems specifically adapted for agricultural propagation of potatoes.
3. Single Correct Answer Type:
Bulbils are commonly found in which plant?
1. Potato
2. Ginger
3. Agave
4. Chlamydomonas
Explanation: The correct answer is Agave. Bulbils are small bulb-like structures produced on aerial parts of Agave. They detach and grow into new plants asexually. Bulbils act as vegetative propagules, ensuring rapid multiplication. Unlike eyes of potato or rhizomes of ginger, they form above ground, providing an effective natural method of propagation and maintaining genetic uniformity without sexual reproduction.
4. Single Correct Answer Type:
Which of the following is NOT a vegetative propagule?
1. Rhizome of Ginger
2. Eyes of Potato
3. Zoospore of Chlamydomonas
4. Bulbil of Agave
Explanation: The correct answer is Zoospore of Chlamydomonas. Zoospores are motile asexual spores produced by algae for reproduction, not vegetative propagation. Vegetative propagules are plant parts like rhizomes, eyes, or bulbils that give rise to a new individual. Zoospores differ because they are reproductive cells capable of dispersal and germination, rather than existing plant structures used for cloning.
5. Single Correct Answer Type:
Rhizome as a vegetative propagule is advantageous because:
1. It produces genetically variable offspring
2. It stores nutrients for sprouting
3. It requires pollination
4. It grows only above ground
Explanation: The correct answer is It stores nutrients for sprouting. Rhizomes store food materials, enabling new shoots and roots to emerge, ensuring survival and propagation. This vegetative propagule allows rapid, uniform multiplication without pollination, unlike sexual reproduction. Nutrient storage also helps plants withstand adverse conditions and ensures energy supply for growth of new plants from the rhizome.
6. Single Correct Answer Type:
Which propagule grows on the body of the parent plant?
1. Rhizome
2. Bulbil
3. Eyes of Potato
4. Zoospore
Explanation: The correct answer is Bulbil. Bulbils are formed on aerial parts of the parent plant and can detach to grow into new plants. Unlike underground rhizomes or eyes of potato, bulbils develop externally. They are vegetative propagules providing asexual reproduction, preserving genetic traits, and facilitating rapid plant multiplication without the need for seeds.
7. Assertion-Reason Type:
Assertion (A): Eyes of potato, rhizome of ginger, and bulbil of Agave are vegetative propagules.
Reason (R): They develop into new individuals without fertilization.
1. Both A and R are true, and R is the correct explanation of A
2. Both A and R are true, but R is not the correct explanation of A
3. A is true, R is false
4. A is false, R is true
Explanation: Both Assertion and Reason are correct. Eyes of potato, rhizomes of ginger, and bulbil of Agave are vegetative propagules because they give rise to new plants asexually. The reason explains the assertion accurately, as these structures bypass sexual reproduction and fertilization, allowing rapid multiplication and preservation of parental genetic traits, which is especially useful in agriculture and horticulture.
8. Matching Type:
Match the propagule with its type:
A. Eyes of Potato → (i) Aerial bud
B. Rhizome of Ginger → (ii) Underground stem
C. Bulbil of Agave → (iii) Aerial bulb-like structure
D. Zoospore → (iv) Motile spore
1. A-(i), B-(ii), C-(iii), D-(iv)
2. A-(ii), B-(i), C-(iv), D-(iii)
3. A-(iii), B-(iv), C-(i), D-(ii)
4. A-(iv), B-(iii), C-(ii), D-(i)
Explanation: Correct matching is A-(i), B-(ii), C-(iii), D-(iv). Eyes of potato are buds on tubers, rhizomes are underground stems, bulbils are aerial bulb-like propagules, and zoospores are motile spores in algae. Vegetative propagules like eyes, rhizomes, and bulbils enable asexual reproduction, whereas zoospores are reproductive but not vegetative, highlighting structural and functional differences.
9. Fill in the Blanks Type:
______ and ______ are examples of vegetative propagules used in agriculture.
1. Zoospore, Buds in Hydra
2. Eyes of Potato, Rhizome of Ginger
3. Zoospore, Bulbil of Agave
4. Buds in Hydra, Rhizome of Ginger
Explanation: The correct answer is Eyes of Potato, Rhizome of Ginger. Both are vegetative propagules, allowing asexual reproduction in plants. They produce new individuals identical to the parent and are widely used in agriculture for rapid, uniform crop propagation. Unlike zoospores or animal buds, these plant structures ensure trait preservation, nutrient storage, and consistent crop yield without sexual reproduction or fertilization.
10. Choose the Correct Statements Type:
Which of the following statements are correct regarding vegetative propagules?
1. Eyes of potato, rhizome, and bulbil are vegetative propagules
2. Zoospore and Hydra buds are vegetative propagules
3. Vegetative propagules reproduce sexually
4. Bulbils develop into new individuals asexually
Explanation: Correct statements are 1 and 4. Eyes of potato, rhizomes, and bulbils are vegetative propagules, reproducing asexually without fertilization. They enable rapid propagation and trait preservation. Zoospores and Hydra buds are asexual reproductive structures but not vegetative propagules. Vegetative propagation is essential in agriculture and horticulture for uniformity, high yield, and fast multiplication of desirable plant varieties.
Topic: Seed Structure and Function; Subtopic: Structure of Monocot and Dicot Seeds
Seed coat: The protective outer covering of a seed that prevents physical damage and dehydration.
Scutellum: A specialized cotyledon found in grass seeds (monocots) that absorbs nutrients from the endosperm.
Endosperm: The nutritive tissue in seed plants formed after fertilization, providing nourishment to the developing embryo.
Pericarp: The wall of a fruit developed from the ovary wall after fertilization, which may consist of exocarp, mesocarp, and endocarp.
Cotyledon: The embryonic leaf in seed-bearing plants, often storing food or aiding in nutrient absorption during germination.
Hypocotyl: The part of a germinating seedling below the cotyledons that develops into the stem.
Endocarp: The innermost layer of the pericarp, surrounding and protecting the seed within a fruit.
Microphyle: A small pore in the seed coat that allows water absorption and gas exchange during germination.
Coleoptile: The sheath protecting a young shoot tip in monocot seedlings as it grows upward.
Embryo: The young developing plant inside a seed, consisting of the embryonic root, shoot, and cotyledons.
Monocot seed: A seed containing one cotyledon, typically having a scutellum and a large endosperm (e.g., maize, wheat).
Lead Question - 2022 (Abroad)
Which of the following set represents the correct labelling of A, B, C and D with respect to the given diagram (outer to innermost)?
A- Seed Coat, B- Cotyledon, C- Endosperm, D - Hypocotyl
A- Seed Coat, B- Scutellum, C- Endocarp, D - Mesocarp
A- Seed Coat, B- Scutellum, C- Microphyle, D - Endocarp
A- Pericarp, B - Coleoptile
Explanation: The correct labelling sequence from outer to inner layers in a monocot seed (like maize) is: A-Seed Coat, B-Scutellum, C-Endosperm, D-Hypocotyl. The seed coat protects the seed, scutellum absorbs nutrients, endosperm stores food, and hypocotyl forms the lower stem region. Hence, option 1 is correct.
Q1: The single cotyledon present in the seed of maize is known as:
Radicle
Scutellum
Endosperm
Epicotyl
Explanation: In monocot seeds like maize, the single cotyledon is called the scutellum. It is a thin, shield-shaped structure that absorbs nutrients from the endosperm to feed the growing embryo. It is characteristic of all members of the grass family. Hence, the correct answer is scutellum.
Q2: The embryonic axis above the level of cotyledons is called:
Radicle
Epicotyl
Hypocotyl
Plumule
Explanation: The epicotyl is the portion of the embryonic axis above the cotyledons. It elongates to form the shoot and leaves after germination. The hypocotyl lies below the cotyledons and connects to the radicle. Hence, the correct answer is epicotyl.
Q3: The nutritive tissue of the seed that nourishes the embryo is:
Pericarp
Endosperm
Scutellum
Micropyle
Explanation: The endosperm is a triploid nutritive tissue formed after double fertilization in angiosperms. It supplies nutrients such as starch, proteins, and oils to the developing embryo during germination. Thus, the correct answer is endosperm.
Q4: The outer covering of the seed is derived from:
Ovary wall
Integuments of ovule
Embryo sac
Funicle
Explanation: The seed coat originates from the integuments of the ovule. The outer integument forms the testa, and the inner integument forms the tegmen. It serves as a protective barrier against desiccation and pathogens. Hence, the correct answer is integuments of ovule.
Q5: The micropyle in a seed helps in:
Food storage
Water absorption
Seed dispersal
Protection of embryo
Explanation: The micropyle is a small pore left in the seed coat through which water enters during germination. It also allows the exchange of gases and passage of pollen tube during fertilization. Hence, water absorption is its main role. Correct answer is water absorption.
Q6: Which of the following is not a part of the embryo?
Plumule
Radicle
Endosperm
Cotyledon
Explanation: The endosperm is not part of the embryo. It is a nutritive tissue that surrounds and nourishes the embryo. The embryo consists of plumule, radicle, and cotyledons. Hence, the correct answer is endosperm.
Q7 (Assertion-Reason): Assertion (A): Maize seed is albuminous. Reason (R): The endosperm persists and stores food even after seed maturation.
(A) is correct but (R) is not correct
(A) is not correct but (R) is correct
Both (A) and (R) are correct and (R) is the correct explanation of (A)
Both (A) and (R) are correct but (R) is not the correct explanation of (A)
Explanation: Maize seeds are albuminous because the endosperm remains persistent and provides nourishment during germination. Both the assertion and reason are correct, and the reason correctly explains the assertion. Therefore, the correct answer is both (A) and (R) are correct and (R) is the correct explanation of (A).
Q8 (Matching Type): Match the parts of a seed with their functions:
1. Scutellum A. Absorbs nutrients from endosperm
2. Micropyle B. Allows water entry
3. Endosperm C. Provides nourishment
4. Testa D. Protects the seed
1-A, 2-B, 3-C, 4-D
1-B, 2-A, 3-D, 4-C
1-C, 2-D, 3-B, 4-A
1-D, 2-C, 3-A, 4-B
Explanation: The scutellum absorbs nutrients from the endosperm (A), the micropyle allows water entry (B), the endosperm provides nourishment (C), and the testa protects the seed (D). Hence, the correct match is 1-A, 2-B, 3-C, 4-D.
Q9 (Fill in the Blank): The portion of the embryonic axis that gives rise to the root system is called ________.
Plumule
Hypocotyl
Radicle
Cotyledon
Explanation: The radicle is the first structure to emerge during germination, forming the primary root system. It ensures anchorage and absorption of water for the growing seedling. Hence, the correct answer is radicle.
Q10 (Choose the Correct Statements): Choose the correct statements:
In maize, the seed is endospermic.
The seed coat is fused with the pericarp.
Scutellum acts as a food-absorbing organ.
Monocot seeds possess two cotyledons.
Explanation: Statements 1, 2, and 3 are correct. Maize seed is endospermic with persistent endosperm; its seed coat fuses with pericarp, and the scutellum functions as an absorptive organ. The last statement is false because monocots have one cotyledon. Correct answer: 1, 2, and 3.
Subtopic: Placentation Types
Placentation: Arrangement of ovules within the ovary of a flower.
Ovule: Structure in seed plants that develops into a seed after fertilization.
Central Axis: The main axis of the ovary where ovules are attached in certain types of placentation.
Septa: Internal walls dividing the ovary into locules.
Axile Placentation: Ovules attached to central axis with septa dividing the ovary.
Free Central Placentation: Ovules attached to central axis without septa; ovary appears unilocular.
Marginal Placentation: Ovules attached along the suture of a single carpel.
Parietal Placentation: Ovules borne on inner ovary wall; ovary appears unilocular.
Flower Anatomy: Study of structural organization of flowers including ovary, ovules, and carpels.
Primrose: Example of free central placentation.
China-rose: Example of axile placentation.
Lead Question - 2022 (Abroad)
Which of the following plants possesses the placentation of ovules borne on central axis with no septa?
Lemon
Pea
China-rose
Primrose
Explanation: Primrose exhibits free central placentation where ovules are attached to a central axis without septa, making the ovary appear unilocular. Lemon and China-rose show axile placentation with septa, and pea has marginal placentation. This type ensures maximum ovule exposure for fertilization. Answer: Primrose. Answer: 4
Q1: In axile placentation, ovules are attached:
To the central axis with septa
Along ovary wall
On one side of carpel
At the base of ovary
Explanation: Axile placentation features ovules attached to the central axis with septa dividing the ovary into multiple locules. This arrangement allows organized ovule distribution and is seen in China-rose and tomato. Answer: To the central axis with septa. Answer: 1
Q2: Marginal placentation is characteristic of:
Pea
Lemon
Primrose
China-rose
Explanation: In marginal placentation, ovules are borne along the suture of a single carpel, typical of legumes like pea. The ovary is unilocular and lacks a central axis or septa. This arrangement ensures a simple linear ovule attachment. Answer: Pea. Answer: 1
Q3: Which type of placentation has ovules attached to inner ovary wall?
Axile
Parietal
Free central
Marginal
Explanation: Parietal placentation features ovules attached to the inner ovary wall in a unilocular ovary. Septa are absent. Examples include mustard and cucumber. It differs from axile and free central placentation. Answer: Parietal. Answer: 2
Q4: Free central placentation is seen in:
Tomato
Cucumber
Primrose
Pea
Explanation: Free central placentation has ovules attached to an unbranched central column without septa. Primrose is a classic example. It provides maximum space for ovules within a single locule, facilitating fertilization. Answer: Primrose. Answer: 3
Q5: The number of locules in free central placentation is usually:
One
Two
Three
Four
Explanation: Free central placentation results in a unilocular ovary because septa are absent. The central axis carries ovules freely, unlike axile placentation, where multiple locules are formed. This design allows efficient seed development. Answer: One. Answer: 1
Q6: Axile placentation differs from free central by:
Presence of septa
Unilocular ovary
Ovules attached along suture
Only one ovule per ovary
Explanation: Axile placentation differs from free central in having septa that divide the ovary into multiple locules, with ovules on the central axis. Free central has no septa and remains unilocular. Examples: China-rose (axile), Primrose (free central). Answer: Presence of septa. Answer: 1
Q7: Assertion (A): Free central placentation lacks septa.
Reason (R): Ovules are attached to a central axis without partitioning.
A is correct but R is not correct
A is not correct but R is correct
Both A and R are correct and R explains A
Both A and R are correct but R does not explain A
Explanation: In free central placentation, ovules are borne on an unbranched central column without septa, making the ovary unilocular. The reason correctly explains the assertion. Both statements are true and logically connected. Answer: Both A and R are correct and R explains A. Answer: 3
Q8: Match plant with its placentation type:
1. Pea A. Marginal
2. China-rose B. Axile
3. Primrose C. Free central
4. Lemon D. Axile
1-A, 2-B, 3-C, 4-D
1-B, 2-D, 3-A, 4-C
1-C, 2-B, 3-A, 4-D
1-D, 2-C, 3-B, 4-A
Explanation: Pea exhibits marginal placentation, China-rose and lemon show axile placentation, and Primrose has free central placentation. This matching clarifies placentation types for different plants. Answer: 1-A, 2-B, 3-C, 4-D. Answer: 1
Q9: In ______ placentation, ovules are attached to the ovary wall.
Axile
Parietal
Free central
Marginal
Explanation: Parietal placentation features ovules attached to the inner ovary wall in a unilocular ovary without septa. It differs from axile and free central placentation where ovules are on a central axis. Examples include mustard. Answer: Parietal. Answer: 2
Q10: Select correct statements regarding free central placentation:
Ovules attached to central axis
No septa present
Ovary is unilocular
Seen in Primrose
Explanation: Free central placentation has ovules on a central axis without septa, resulting in a unilocular ovary. Primrose is a classical example. All statements are correct and describe the characteristic features of free central placentation. Answer: All of the above. Answer: 1,2,3,4
Topic: Ploidy and Plant Life Cycle
Subtopic: Haploid and Diploid Structures
Haploid: A cell or structure containing a single set of chromosomes (n).
Diploid: A cell containing two sets of chromosomes (2n).
Microspore: Haploid spore produced by meiosis in microsporangia, gives rise to male gametophyte.
Microspore Mother Cell: Diploid cell in anther that undergoes meiosis to produce haploid microspores.
Endosperm: Tissue in seeds, usually triploid (3n) in dicots, formed by fusion of sperm with polar nuclei.
Protonemal Cell: Haploid filamentous stage of moss gametophyte developing from spore.
Primary Endospore Nucleus: Early nucleus formed in spores; ploidy depends on parent cell.
Dicot: Angiosperm plant with two cotyledons in seed.
Double Fertilization: Process where one sperm fertilizes egg forming zygote and another fertilizes central cell forming endosperm.
Gametophyte: Haploid phase of plant life cycle producing gametes.
Sporophyte: Diploid phase producing spores via meiosis.
Lead Question - 2022 (Abroad)
Which one of the following structures is haploid in its ploidy level?
Primary Endospore Nucleus
Microspore Mother cell
Protonemal cell of a moss
Primary endosperm nucleus in dicot
Explanation: Haploid cells contain one set of chromosomes (n). Protonemal cells of moss develop from haploid spores and are part of the gametophyte, thus haploid. Microspore mother cells are diploid (2n), endosperm nucleus is typically triploid (3n), and primary endospore nucleus ploidy depends on parent. Correct answer: Protonemal cell of a moss. Answer: 3
Q1: Which stage of plant life cycle is haploid?
Sporophyte
Gametophyte
Zygote
Endosperm
Explanation: Gametophyte stage in plants is haploid (n) and produces gametes via mitosis. Sporophyte is diploid (2n), zygote is diploid, and endosperm is usually triploid. Therefore, haploid stage is gametophyte. Answer: Gametophyte. Answer: 2
Q2: In angiosperms, microspores are produced by:
Mitosis of microspore mother cell
Meiosis of microspore mother cell
Fertilization of egg
Mitosis of gametophyte
Explanation: Microspores arise from meiosis of diploid microspore mother cells in anther. Each microspore is haploid (n) and develops into male gametophyte. Fertilization and mitosis of gametophyte produce zygote or gametes, not microspores. Answer: Meiosis of microspore mother cell. Answer: 2
Q3: Primary endosperm nucleus in dicots is:
Haploid
Diploid
Triploid
Tetraploid
Explanation: In dicots, primary endosperm nucleus forms by fusion of one sperm (n) with two polar nuclei (each n), giving triploid (3n) endosperm. Haploid or diploid options are incorrect. Answer: Triploid. Answer: 3
Q4: Protonemal cell arises from:
Diploid spore
Haploid spore
Endosperm
Zygote
Explanation: Moss spores are haploid, and they germinate to form protonemal filaments (haploid), which then produce gametophytes. Diploid spores, endosperm, or zygote do not form protonema. Answer: Haploid spore. Answer: 2
Q5: Which of the following structures is diploid?
Protonemal cell
Microspore
Microspore mother cell
Gamete
Explanation: Microspore mother cell is diploid (2n) and undergoes meiosis to produce haploid microspores. Protonema, microspore, and gametes are haploid. Answer: Microspore mother cell. Answer: 3
Q6: Which structure gives rise to male gametophyte in flowering plants?
Microspore
Megaspore
Sperm
Primary endosperm nucleus
Explanation: Microspores are haploid spores produced by meiosis in anther. Each develops into male gametophyte (pollen grain). Megaspore forms female gametophyte, sperm participates in fertilization, and primary endosperm nucleus forms endosperm. Answer: Microspore. Answer: 1
Q7: Assertion (A): Protonemal cells of moss are haploid.
Reason (R): Moss life cycle alternates between haploid gametophyte and diploid sporophyte.
A is correct but R is not correct
A is not correct but R is correct
Both A and R are correct and R explains A
Both A and R are correct but R does not explain A
Explanation: Protonemal cells arise from haploid spores and form gametophyte. Moss exhibits alternation of generations: haploid gametophyte and diploid sporophyte. Both assertion and reason are correct, and reason explains why protonemal cells are haploid. Answer: Both A and R are correct and R explains A. Answer: 3
Q8: Match plant structures with ploidy:
A. Zygote 1. n
B. Gamete 2. 2n
C. Endosperm (dicot) 3. 3n
A-2, B-1, C-3
A-1, B-2, C-3
A-2, B-2, C-1
A-3, B-1, C-2
Explanation: Zygote is diploid (2n), gamete is haploid (n), and dicot endosperm is triploid (3n). Correct matching: A-2, B-1, C-3. Answer: 1
Q9: The haploid filamentous stage in moss is called ______.
Protonema
Sporophyte
Gametophyte
Endosperm
Explanation: Protonema is the haploid filamentous stage of moss developing from spore. It forms gametophyte which produces gametes. Sporophyte is diploid, gametophyte is mature haploid plant, endosperm is triploid. Answer: Protonema. Answer: 1
Q10: Choose correct statements about haploid structures:
Protonemal cell is haploid
Microspore is haploid
Microspore mother cell is haploid
Gametophyte is haploid
Explanation: Protonemal cells, microspores, and gametophytes are haploid. Microspore mother cells are diploid. Correct statements: 1, 2, 4. Answer: 1, 2, 4
Topic: Ploidy and Endosperm Formation
Subtopic: Endosperm Ploidy
Ploidy: Number of sets of chromosomes in a cell or nucleus.
Endosperm: Tissue in seeds formed after fertilization, nourishing the embryo.
Tetraploid: Organism or cell having four sets of chromosomes (4n).
Fertilization: Fusion of male and female gametes forming zygote.
Triploid: Cell or organism with three sets of chromosomes (3n).
Pentaploid: Cell or organism with five sets of chromosomes (5n).
Hexaploid: Cell or organism with six sets of chromosomes (6n).
Double fertilization: Unique process in angiosperms where one sperm fertilizes egg and another sperm fertilizes central cell to form endosperm.
Central cell: Cell in female gametophyte containing two polar nuclei, fuses with sperm to form endosperm.
Embryo: Young sporophyte formed after fertilization of egg cell.
Seed: Mature ovule containing embryo, endosperm, and seed coat.
Lead Question - 2022 (Abroad)
What will be the ploidy of endosperm of a seed produced after crossing tetraploid female plant with tetraploid male plant?
Pentaploid
Hexaploid
Diploid
Triploid
Explanation: In angiosperms, endosperm is formed by double fertilization: one sperm fuses with two polar nuclei. Female tetraploid provides 2n + 2n = 4n polar nuclei, male tetraploid sperm contributes 4n. Endosperm ploidy = 4n (polar nuclei) + 4n (sperm) = 8n. Therefore, none of the given options matches; conceptually, hexaploid is often assumed in tetraploid × tetraploid cases if central cell is 2n, but strictly, ploidy is 6n. Answer: Hexaploid. Answer: 2
Q1: In double fertilization, one sperm fertilizes the egg to form zygote and the other fertilizes:
Egg cell
Central cell
Synergid
Antipodal cell
Explanation: In angiosperms, double fertilization involves one sperm fusing with egg to form zygote, while the second sperm fuses with central cell containing two polar nuclei to form endosperm. Synergids and antipodals assist but do not fuse with sperm. Answer: Central cell. Answer: 2
Q2: Ploidy of embryo formed after fertilization of tetraploid female and male plants will be:
Diploid
Triploid
Tetraploid
Hexaploid
Explanation: Embryo forms by fusion of egg and sperm. Tetraploid female egg (4n) fertilized by tetraploid male sperm (4n) results in embryo ploidy 4n + 4n = 8n. However, in most texts, the female egg is considered 2n (reduced gamete), resulting in tetraploid embryo. Answer: Tetraploid. Answer: 3
Q3: Which type of tissue nourishes developing embryo in seeds?
Endosperm
Embryo sac
Seed coat
Perisperm
Explanation: Endosperm is triploid or higher ploidy tissue formed by fusion of sperm with polar nuclei, serving as nutrient reserve for embryo. Embryo sac houses gametes, seed coat protects, and perisperm is maternal tissue in some seeds. Answer: Endosperm. Answer: 1
Q4: Central cell of angiosperm embryo sac typically contains how many polar nuclei?
One
Two
Three
Four
Explanation: The central cell contains two haploid polar nuclei, which fuse with a sperm to form endosperm. This is crucial for determining endosperm ploidy. Answer: Two. Answer: 2
Q5: Crossing tetraploid female with diploid male, endosperm ploidy becomes:
Triploid
Pentaploid
Hexaploid
Octaploid
Explanation: Female tetraploid central cell contributes 4n polar nuclei, male diploid sperm contributes 2n. Endosperm ploidy = 4n + 2n = 6n (hexaploid). Answer: Hexaploid. Answer: 3
Q6: Fusion of sperm with egg in double fertilization forms:
Endosperm
Zygote
Polar nuclei
Seed coat
Explanation: Sperm fusing with egg produces zygote, which develops into the embryo. Sperm with polar nuclei forms endosperm. Polar nuclei and seed coat are not products of fertilization fusion. Answer: Zygote. Answer: 2
Q7: Assertion (A): Endosperm ploidy depends on female and male gamete ploidy.
Reason (R): Endosperm is formed by fusion of one sperm with two polar nuclei.
A is correct but R is not correct
A is not correct but R is correct
Both A and R are correct and R explains A
Both A and R are correct but R does not explain A
Explanation: Endosperm ploidy results from fusion of sperm (male) with two polar nuclei (female). Therefore, the assertion is correct and reason correctly explains why endosperm ploidy depends on both gametes. Answer: Both A and R are correct and R explains A. Answer: 3
Q8: Match gametes with their ploidy in tetraploid plant:
A. Egg 1. 2n
B. Sperm 2. 2n
C. Polar nuclei 3. 2n
A-1, B-2, C-3
A-2, B-1, C-3
A-1, B-3, C-2
A-2, B-2, C-2
Explanation: In tetraploid plants, gametes are reduced to 2n. Egg is 2n, sperm is 2n, and each polar nucleus is 2n (combined 4n for endosperm). Correct match is A-2, B-2, C-2. Answer: A-2, B-2, C-2. Answer: 4
Q9: Tissue that provides nutrients to embryo is ______.
Endosperm
Embryo
Seed coat
Perisperm
Explanation: Endosperm provides food reserves for developing embryo, formed by double fertilization. Seed coat protects, perisperm is maternal tissue, and embryo develops into new plant. Answer: Endosperm. Answer: 1
Q10: Which of the following statements about endosperm are correct?
Formed by fusion of sperm with polar nuclei
Nourishes embryo
Ploidy depends on parent ploidy
Forms seed coat
Explanation: Endosperm forms by fertilization of polar nuclei by sperm, nourishes embryo, and its ploidy depends on parental gamete ploidy. Seed coat is maternal tissue, not endosperm. Correct statements are 1, 2, 3. Answer: 1, 2, 3
Topic: Floral Whorls
Subtopic: Androecium and its Variations
Keyword Definitions:
- Androecium: The male reproductive whorl of a flower consisting of stamens.
- Stamen: The male reproductive organ comprising anther and filament.
- Staminode: A sterile stamen that does not produce pollen.
- Epipetalous: Stamens attached to petals, common in Solanaceae and Asteraceae.
- Monadelphous: Stamens united by filaments into one bundle, as in China rose.
- Polyadelphous: Stamens united by filaments into many bundles, as in citrus.
- Diadelphous: Stamens united into two bundles, as in pea family (Fabaceae).
- Didynamous: Two pairs of stamens, one long and one short, as in mustard.
- Tetradynamous: Four long and two short stamens, typical of Brassicaceae (mustard).
- Filament: The slender stalk of the stamen supporting the anther.
Lead Question - 2022 (Abroad):
Identify the correct statements related to the androecium in the flower.
(a) The sterile stamens are called staminodes
(b) When stamens are attached to petals they are called epipetalous
(c) Monadelphy is seen in China-rose
(d) Polyadelphy is seen in Pea
(e) Variation in the length of anther filaments is seen in Mustard
1. (a), (c), (d) and (e) only
2. (a), (b), (c) and (e) only
3. (a), (b) and (c) only
4. (b), (c) and (d) only
Explanation: The correct answer is (2). Staminodes are sterile stamens, epipetalous stamens attach to petals, monadelphous stamens are found in China rose, and mustard shows didynamous condition with unequal stamens. Polyadelphy occurs in citrus, not pea, which has diadelphous stamens.
1. Which of the following plants shows monadelphous stamens?
(a) Pea
(b) Citrus
(c) Hibiscus
(d) Mustard
Explanation: The correct answer is (c). In Hibiscus (China rose), stamens are united by filaments into a single bundle forming a staminal tube around the style. This is called monadelphous condition and is characteristic of the Malvaceae family.
2. Polyadelphous stamens are found in:
(a) Citrus
(b) Pea
(c) Mustard
(d) Solanum
Explanation: The correct answer is (a). In Citrus, stamens are united into many groups by filaments, forming the polyadelphous condition. This structure provides support and enhances pollen release efficiency during pollination.
3. Didynamous condition of stamens is a feature of:
(a) Mustard
(b) Ocimum
(c) Pea
(d) Citrus
Explanation: The correct answer is (b). In Ocimum (Lamiaceae family), four stamens are arranged in two pairs of unequal length, known as didynamous condition, which aids in effective pollination through specialized flower structure.
4. Tetradynamous condition is seen in which family?
(a) Solanaceae
(b) Malvaceae
(c) Fabaceae
(d) Brassicaceae
Explanation: The correct answer is (d). In Brassicaceae (mustard family), six stamens are present, four long and two short, forming the tetradynamous condition, helping in pollen transfer through balanced arrangement.
5. Diadelphous stamens are a characteristic feature of:
(a) Fabaceae
(b) Malvaceae
(c) Asteraceae
(d) Brassicaceae
Explanation: The correct answer is (a). In Fabaceae, stamens are united into two bundles by their filaments forming the diadelphous condition, typically seen in pea, which aids in effective pollination by insects.
6. Stamens attached to petals are called:
(a) Epipetalous
(b) Epiphyllous
(c) Epiphyte
(d) Monadelphous
Explanation: The correct answer is (a). When stamens are fused with petals, they are termed epipetalous, a common feature in Solanaceae and Asteraceae families, ensuring proximity between anthers and pollinators for effective pollination.
7. Assertion-Reason:
Assertion (A): Stamens in pea are diadelphous.
Reason (R): All filaments are united into a single bundle.
(a) Both A and R are true, and R explains A
(b) Both A and R are true, but R does not explain A
(c) A is true, but R is false
(d) Both A and R are false
Explanation: The correct answer is (c). Stamens in pea are diadelphous where 9 stamens are united and 1 remains free. The reason is false since all filaments are not united into one bundle but into two.
8. Matching Type:
Match the plant with its stamen condition:
(a) Hibiscus - (i) Monadelphous
(b) Citrus - (ii) Polyadelphous
(c) Pea - (iii) Diadelphous
(d) Mustard - (iv) Tetradynamous
Options:
1. (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv)
2. (a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)
3. (a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)
4. (a)-(iv), (b)-(ii), (c)-(i), (d)-(iii)
Explanation: The correct answer is (1). Hibiscus is monadelphous, Citrus polyadelphous, Pea diadelphous, and Mustard tetradynamous. These stamen arrangements assist in diverse pollination mechanisms among angiosperms.
9. Fill in the Blank:
Stamens fused with the corolla are called ________.
(a) Epipetalous
(b) Epiphyllous
(c) Monadelphous
(d) Polyadelphous
Explanation: The correct answer is (a). Epipetalous stamens are fused with the corolla, ensuring better positioning of anthers for pollination, commonly seen in flowers of the Solanaceae family.
10. Choose the Correct Statements:
1. Epipetalous stamens attach to petals.
2. Monadelphous condition occurs in China rose.
3. Diadelphous stamens occur in Pea.
4. Polyadelphous stamens occur in Pea.
(a) 1, 2, and 3 only
(b) 1 and 3 only
(c) 2 and 4 only
(d) 1, 2, 3, and 4
Explanation: The correct answer is (a). Epipetalous stamens are attached to petals, China rose shows monadelphous stamens, and Pea shows diadelphous condition. Polyadelphous condition is seen in Citrus, not in Pea.
Topic: Flower Symmetry
Subtopic: Zygomorphic and Actinomorphic Flowers
Keyword Definitions:
Zygomorphic: Flowers that can be divided into equal halves in only one plane, showing bilateral symmetry.
Actinomorphic: Flowers that can be divided into equal halves along multiple planes, showing radial symmetry.
Mustard: A plant with actinomorphic flowers, family Brassicaceae.
Glumohar: Also called Delonix regia, tree with zygomorphic flowers.
Cassia: A genus of leguminous plants with zygomorphic flowers.
Datura: Genus with actinomorphic flowers, family Solanaceae.
Chilly: Capsicum species, flowers are actinomorphic.
Flower symmetry: The arrangement of floral parts and their ability to be divided into equal halves.
Bilateral symmetry: Same as zygomorphic symmetry, only one plane of division.
Radial symmetry: Same as actinomorphic symmetry, multiple planes of division.
Lead Question (2022)
The flowers are Zygomorphic in
(a) Mustard
(b) Glumohar
(c) Cassia
(d) Datura
(e) Chilly
Choose the correct answer from the options given below:
(1) (b), (c) only
(2) (d), (e) only
(3) (c), (d), (e) only
(4) (a), (b), (c) only
Explanation:
Zygomorphic flowers have bilateral symmetry, meaning they can be divided into equal halves in only one plane. Glumohar (b) and Cassia (c) exhibit this symmetry, whereas Mustard, Datura, and Chilly have actinomorphic flowers with radial symmetry. Therefore, the correct answer is (1).
1. Single Correct Answer MCQ:
Which flower exhibits radial symmetry?
(1) Glumohar
(2) Cassia
(3) Mustard
(4) None of these
Explanation:
Radial symmetry is shown by flowers that can be divided into equal halves along multiple planes. Mustard flowers are actinomorphic, exhibiting radial symmetry, while Glumohar and Cassia are zygomorphic. Correct answer is (3).
2. Single Correct Answer MCQ:
Bilateral symmetry in flowers is also called:
(1) Actinomorphic
(2) Zygomorphic
(3) Radial
(4) Asymmetrical
Explanation:
Bilateral symmetry means the flower can be divided into two equal halves along only one plane, called zygomorphic symmetry. Actinomorphic refers to radial symmetry. Correct answer is (2).
3. Single Correct Answer MCQ:
Which family is known for zygomorphic flowers?
(1) Fabaceae
(2) Brassicaceae
(3) Solanaceae
(4) Solanaceae and Brassicaceae
Explanation:
Fabaceae (legume family) often shows zygomorphic flowers, like Cassia. Brassicaceae (Mustard) and Solanaceae (Datura) generally have actinomorphic flowers. Therefore, Fabaceae is correct. Correct answer is (1).
4. Single Correct Answer MCQ:
Glumohar flowers are:
(1) Actinomorphic
(2) Zygomorphic
(3) Asymmetrical
(4) None of these
Explanation:
Glumohar (Delonix regia) flowers are bilateral and show zygomorphic symmetry, meaning they can be divided in only one plane into equal halves. Correct answer is (2).
5. Single Correct Answer MCQ:
Which of the following is actinomorphic?
(1) Cassia
(2) Glumohar
(3) Mustard
(4) None of these
Explanation:
Actinomorphic flowers have radial symmetry, which can be divided along multiple planes. Mustard shows actinomorphic flowers, whereas Cassia and Glumohar are zygomorphic. Correct answer is (3).
6. Single Correct Answer MCQ:
Which plant has bilateral flowers used in pollination studies?
(1) Glumohar
(2) Datura
(3) Chilly
(4) Mustard
Explanation:
Glumohar exhibits zygomorphic flowers and is often used to study bilateral flower-pollinator interactions. Datura, Chilly, and Mustard have radial flowers. Correct answer is (1).
7. Assertion-Reason MCQ:
Assertion (A): Cassia flowers are zygomorphic.
Reason (R): Zygomorphic flowers can be divided into equal halves in multiple planes.
Options:
(1) Both A and R correct, R explains A
(2) A correct, R incorrect
(3) A incorrect, R correct
(4) Both A and R incorrect
Explanation:
Cassia flowers are zygomorphic, but zygomorphic flowers are divided into equal halves in only one plane. Hence, A is correct, R is incorrect. Correct answer is (2).
8. Matching Type MCQ:
Match flower with symmetry:
A. Mustard — 1. Zygomorphic
B. Glumohar — 2. Actinomorphic
C. Cassia — 3. Zygomorphic
D. Datura — 4. Actinomorphic
Options:
(1) A–2, B–1, C–3, D–4
(2) A–1, B–2, C–3, D–4
(3) A–2, B–3, C–1, D–4
(4) A–4, B–1, C–2, D–3
Explanation:
Mustard (actinomorphic–2), Glumohar (zygomorphic–1), Cassia (zygomorphic–3), Datura (actinomorphic–4). This matches option (1).
9. Fill in the Blanks MCQ:
Zygomorphic flowers can be divided into equal halves in ________ plane.
(1) One
(2) Two
(3) Multiple
(4) None
Explanation:
Zygomorphic flowers exhibit bilateral symmetry, allowing division into two equal halves in only one plane. Correct answer is (1).
10. Choose the correct statements MCQ:
(a) Datura flowers are zygomorphic
(b) Cassia flowers are zygomorphic
(c) Mustard flowers are actinomorphic
(d) Glumohar flowers are zygomorphic
Options:
(1) a, b, c
(2) b, c, d
(3) a, c, d
(4) b, d only
Explanation:
Cassia and Glumohar show zygomorphic flowers, Mustard is actinomorphic, Datura is actinomorphic. Correct combination is (2).
Topic: Pollination
Subtopic: Types and Agents of Pollination
Keyword Definitions:
Pollination: Transfer of pollen grains from anther to stigma to enable fertilization.
Abiotic Pollination: Pollination not involving living organisms, typically by wind or water.
Biotic Pollination: Pollination involving living agents like insects, birds, or animals.
Moths: Nocturnal insects that pollinate flowers with pale colors and strong scent at night.
Butterflies: Diurnal insects pollinating bright, fragrant flowers during day.
Foul Odour: Unpleasant smell produced by some flowers to attract flies and beetles for pollination.
Water Pollination: Rare method of abiotic pollination, usually in aquatic plants.
Wind Pollination: Common abiotic pollination method, especially in grasses, cereals, and some trees.
Beetles: Insects attracted to strong-smelling or fruity flowers, aiding pollination.
Flower Agents: Organisms or environmental factors that facilitate transfer of pollen.
Lead Question (2022)
Identify the incorrect statement related to Pollination:
(1) Pollination by wind is more common amongst abiotic pollination
(2) Flowers produce foul odours to attract flies and beetles to get pollinated
(3) Moths and butterflies are the most dominant pollinating agents among insects
(4) Pollination by water is quite rare in flowering plants
Explanation:
Among insects, bees, not moths and butterflies, are the most dominant pollinators, making statement (3) incorrect. Wind pollination is common among abiotic agents, foul odours attract flies and beetles, and water pollination is rare. Correct answer is (3).
1. Single Correct Answer MCQ:
Which type of flower is usually pollinated by beetles?
(1) Odorless, small flowers
(2) Flowers with foul odor and strong color
(3) Wind-pollinated flowers
(4) Water-borne flowers
Explanation:
Beetles are attracted to flowers with foul odors, fruity scents, or strong colors. These features ensure effective pollination. Odorless, wind, or water-pollinated flowers are not suitable for beetle pollination. Correct answer is (2).
2. Single Correct Answer MCQ:
The most common abiotic pollination method is:
(1) Water
(2) Wind
(3) Insects
(4) Birds
Explanation:
Wind pollination is the predominant abiotic method, seen in grasses, cereals, and some trees. Water pollination is rare, and insects or birds are biotic pollinators. Correct answer is (2).
3. Single Correct Answer MCQ:
Which insect is most dominant in pollination?
(1) Butterfly
(2) Moth
(3) Bee
(4) Beetle
Explanation:
Bees are the most efficient and dominant insect pollinators due to their frequent flower visits, pollen-collecting behavior, and hairy body structure that carries pollen. Butterflies and moths also pollinate but are less dominant. Correct answer is (3).
4. Single Correct Answer MCQ:
Water pollination occurs mostly in:
(1) Terrestrial trees
(2) Aquatic plants
(3) Desert plants
(4) Wind-pollinated grasses
Explanation:
Water pollination (hydrophily) is a rare form of abiotic pollination occurring in aquatic plants where pollen floats on water to reach the stigma. Terrestrial and desert plants rely on wind or insects. Correct answer is (2).
5. Single Correct Answer MCQ:
Which type of flower typically produces foul odors to attract pollinators?
(1) Rose
(2) Rafflesia
(3) Sunflower
(4) Hibiscus
Explanation:
Flowers like Rafflesia produce foul odors to attract flies and beetles for pollination. Roses and hibiscus rely on color and fragrance, sunflower is wind-pollinated. Correct answer is (2).
6. Single Correct Answer MCQ:
Which agent does not participate in abiotic pollination?
(1) Wind
(2) Water
(3) Birds
(4) None of these
Explanation:
Abiotic pollination relies on non-living agents like wind and water. Birds are living pollinators and thus participate in biotic pollination. Correct answer is (3).
7. Assertion-Reason MCQ:
Assertion (A): Water pollination is rare among flowering plants.
Reason (R): Only aquatic plants have adaptations for hydrophily.
Options:
(1) Both A and R are correct, R explains A
(2) A correct, R incorrect
(3) A incorrect, R correct
(4) Both A and R incorrect
Explanation:
Water pollination occurs rarely because only aquatic plants have pollen adapted for dispersal on water surfaces. This explains why hydrophily is uncommon. Correct answer is (1).
8. Matching Type MCQ:
Match pollinator with the flower type:
A. Fly — 1. Foul smelling flowers
B. Butterfly — 2. Bright, fragrant flowers
C. Wind — 3. Odorless, small flowers
D. Beetle — 4. Strong scented, often large flowers
Options:
(1) A–1, B–2, C–3, D–4
(2) A–2, B–1, C–3, D–4
(3) A–3, B–2, C–1, D–4
(4) A–1, B–3, C–2, D–4
Explanation:
Flies are attracted to foul-smelling flowers, butterflies to bright, fragrant flowers, wind pollinates odorless, small flowers, and beetles prefer strong-scented or large flowers. Correct answer is (1).
9. Fill in the Blanks MCQ:
Pollination that occurs without the involvement of living agents is called ________.
(1) Biotic pollination
(2) Abiotic pollination
(3) Insect pollination
(4) Bird pollination
Explanation:
Abiotic pollination occurs without living agents, typically via wind or water. Biotic pollination involves animals like insects or birds. Correct answer is (2).
10. Choose the correct statements MCQ:
(a) Wind pollination is common in grasses
(b) Bees are dominant insect pollinators
(c) Water pollination is frequent in flowering plants
(d) Flowers producing foul odors are pollinated by flies
Options:
(1) a, b, d only
(2) a, b, c only
(3) b, c, d only
(4) a, c, d only
Explanation:
Wind pollination is common in grasses (a), bees dominate insect pollination (b), and flowers with foul odors attract flies (d). Water pollination is rare, not frequent. Correct answer is (1).
Topic: Floral Characters
Subtopic: Aestivation and Stamens
Keyword Definitions:
Vexillary Aestivation: Arrangement of five petals in papilionaceous flowers where one large petal (standard) overlaps two lateral petals (wings) and the wings overlap the two lower petals (keel).
Diadelphous Stamens: Stamens united by filaments into two bundles, common in Fabaceae family.
Pisum sativum: Common pea plant, papilionaceous flower with vexillary aestivation and diadelphous stamens.
Allium cepa: Onion plant with free stamens and imbricate aestivation.
Solanum nigrum: Nightshade, flower has free stamens and valvate or twisted aestivation.
Colchicum autumnale: Autumn crocus, flower has free stamens and imbricate aestivation.
Aestivation: The arrangement of petals or sepals in a flower bud.
Stamens: Male reproductive organ of flower, composed of filament and anther.
Papilionaceous Flower: Butterfly-shaped flower typical of Fabaceae family.
Keel: Two fused lower petals in papilionaceous flowers enclosing reproductive organs.
Lead Question (2022)
Which one of the following plants shows vexillary aestivation and diadelphous stamens?
(1) Pisum sativum
(2) Allium cepa
(3) Solanum nigrum
(4) Colchicum automnale
Explanation:
Pisum sativum exhibits papilionaceous flowers with vexillary aestivation where the large standard petal overlaps lateral wings and keel petals. Its ten stamens are diadelphous, nine fused and one free. Other plants listed do not show both features. Correct answer is (1).
1. Single Correct Answer MCQ:
In papilionaceous flowers, the keel petals enclose:
(1) Ovary only
(2) Stamens and pistil
(3) Nectar only
(4) Calyx
Explanation:
The two fused lower petals called keel enclose the reproductive organs: stamens and pistil. This protects them and facilitates pollination. Other options are incorrect. Correct answer is (2).
2. Single Correct Answer MCQ:
Diadelphous stamens are characteristic of which family?
(1) Solanaceae
(2) Fabaceae
(3) Liliaceae
(4) Colchicaceae
Explanation:
Diadelphous stamens, where stamens are united into two groups by filaments, are typical of the Fabaceae family. Other families listed have free stamens. Correct answer is (2).
3. Single Correct Answer MCQ:
The largest petal in a papilionaceous flower is called:
(1) Wing
(2) Standard
(3) Keel
(4) Sepal
Explanation:
The standard is the largest and uppermost petal in papilionaceous flowers, which protects inner petals and attracts pollinators. Wings are lateral, keel petals are lower, and sepals form calyx. Correct answer is (2).
4. Single Correct Answer MCQ:
Vexillary aestivation is an example of:
(1) Contorted
(2) Twisted
(3) Papilionaceous
(4) Imbricate
Explanation:
Vexillary aestivation is the arrangement of petals in papilionaceous flowers where the standard overlaps wings and keel petals. This type is characteristic of Fabaceae. Other options describe different petal arrangements. Correct answer is (3).
5. Single Correct Answer MCQ:
Number of stamens typically diadelphous in Pisum sativum is:
(1) 5
(2) 10
(3) 8
(4) 6
Explanation:
Pisum sativum has ten stamens, nine fused by filaments and one free, forming diadelphous stamens. This arrangement facilitates pollination. Other options are incorrect. Correct answer is (2).
6. Single Correct Answer MCQ:
The lateral petals of papilionaceous flower are called:
(1) Standard
(2) Wings
(3) Keel
(4) Sepals
Explanation:
Wings are the lateral petals of papilionaceous flowers, situated on both sides of the keel and standard. They aid in protecting reproductive organs and pollinator guidance. Correct answer is (2).
7. Assertion-Reason MCQ:
Assertion (A): Pisum sativum has diadelphous stamens.
Reason (R): Diadelphous stamens consist of two groups of stamens, one free and remaining fused.
Options:
(1) Both A and R are correct, R explains A
(2) A correct, R incorrect
(3) A incorrect, R correct
(4) Both A and R incorrect
Explanation:
Diadelphous stamens in Pisum sativum consist of nine stamens fused and one free. This description accurately explains the assertion. Correct answer is (1).
8. Matching Type MCQ:
Match plant with its floral character:
A. Pisum sativum — 1. Vexillary aestivation
B. Allium cepa — 2. Imbricate aestivation
C. Solanum nigrum — 3. Valvate aestivation
D. Colchicum autumnale — 4. Imbricate aestivation
Options:
(1) A–1, B–2, C–3, D–4
(2) A–2, B–1, C–4, D–3
(3) A–1, B–3, C–2, D–4
(4) A–3, B–2, C–1, D–4
Explanation:
Pisum sativum has vexillary aestivation. Allium cepa and Colchicum autumnale show imbricate aestivation. Solanum nigrum exhibits valvate aestivation. Correct answer is (1).
9. Fill in the Blanks MCQ:
The flower type with one large standard petal, two wings and two fused lower petals is called ________.
(1) Papilionaceous
(2) Solanaceous
(3) Cruciferous
(4) Liliaceous
Explanation:
Papilionaceous flowers are characteristic of Fabaceae, with one standard, two wings, and a fused keel of two petals. Other options refer to different families with unrelated floral structures. Correct answer is (1).
10. Choose the correct statements MCQ:
(a) Pisum sativum shows vexillary aestivation
(b) Diadelphous stamens are found in Fabaceae
(c) Allium cepa has diadelphous stamens
(d) Keel petals enclose reproductive organs
Options:
(1) a, b, d only
(2) a, c, d only
(3) b, c only
(4) a, b, c, d
Explanation:
Pisum sativum shows vexillary aestivation (a), diadelphous stamens are typical of Fabaceae (b), and keel petals enclose reproductive organs (d). Allium cepa does not have diadelphous stamens. Correct answer is (1).
Subtopic: Cleistogamy and Autogamy
Keyword Definitions:
Cleistogamous flowers: Flowers that do not open and self-pollinate within the closed bud.
Autogamous: Self-pollination occurring within the same flower, ensuring seed formation.
Cross-pollination: Transfer of pollen between different flowers or plants, increasing genetic diversity.
Advantage of cleistogamy: Ensures reproduction even in absence of pollinators.
Disadvantage of cleistogamy: Lack of genetic variation due to absence of cross-pollination.
Lead Question (2022)
Given below are two statements:
Statement I: Cleistogamous flowers are invariably autogamous
Statement II: Cleistogamy is disadvantageous as there is no chance for cross-pollination
Options:
(1) Both statement I and statement II are incorrect
(2) Statement I is correct but statement II is incorrect
(3) Statement I is incorrect but statement II is correct
(4) Both statement I and statement II are correct
Explanation:
Cleistogamous flowers always self-pollinate and are therefore autogamous, making Statement I correct. However, cleistogamy is not entirely disadvantageous; it guarantees seed set even without pollinators, so Statement II is incorrect. Correct answer is (2). Cleistogamy ensures reproduction but limits genetic diversity, not a strict disadvantage.
1. Which type of flowers remain closed and self-pollinate?
(1) Chasmogamous
(2) Cleistogamous
(3) Bisexual
(4) Unisexual
Explanation:
Cleistogamous flowers never open and always self-pollinate within the bud, ensuring reproduction without external pollinators. Chasmogamous flowers open and may undergo cross-pollination. Correct answer is (2).
2. Cleistogamy is advantageous because:
(1) It ensures seed formation without pollinators
(2) It allows maximum genetic diversity
(3) It promotes cross-pollination
(4) Flowers bloom in all seasons
Explanation:
Cleistogamous flowers self-pollinate inside closed buds, ensuring seed formation even in absence of pollinators or adverse conditions. It does not promote genetic diversity or cross-pollination. Correct answer is (1).
3. Autogamy refers to:
(1) Self-pollination within a flower
(2) Pollination between two flowers
(3) Pollination by insects
(4) Seed dispersal mechanism
Explanation:
Autogamy is self-pollination occurring within the same flower, leading to seed formation without need for pollen transfer. Correct answer is (1).
4. Disadvantage of cleistogamy includes:
(1) No seed formation
(2) Limited genetic diversity
(3) Requires pollinators
(4) Flowers remain open
Explanation:
Since cleistogamous flowers always self-pollinate, cross-pollination does not occur, leading to limited genetic diversity. Seed formation is ensured, and pollinators are not required. Correct answer is (2).
5. Cleistogamous flowers are commonly found in:
(1) Viola and Oxalis
(2) Hibiscus and Rose
(3) Sunflower and Mustard
(4) Maize and Wheat
Explanation:
Plants like Viola and Oxalis produce cleistogamous flowers that self-pollinate inside closed buds. Hibiscus, rose, sunflower, and mustard mainly produce chasmogamous flowers. Correct answer is (1).
6. Single Correct Answer MCQ:
Which is true for cleistogamous flowers?
(1) Always cross-pollinated
(2) Always autogamous
(3) Only produce male gametes
(4) Require insect pollinators
Explanation:
Cleistogamous flowers never open and always self-pollinate, making them autogamous. They do not rely on pollinators or cross-pollination. Correct answer is (2).
7. Assertion-Reason MCQ:
Assertion (A): Cleistogamy ensures reproduction without pollinators
Reason (R): It increases genetic diversity
Options:
(1) Both A and R correct, R explains A
(2) A correct, R incorrect
(3) A incorrect, R correct
(4) Both A and R incorrect
Explanation:
Cleistogamy ensures seed formation without pollinators, but it does not enhance genetic diversity due to self-pollination. Hence, Assertion is correct, Reason is incorrect. Correct answer is (2).
8. Matching Type MCQ:
Match flowers with pollination type:
A. Cleistogamous — 1. Self-pollination
B. Chasmogamous — 2. Cross-pollination
Options:
(1) A–1, B–2
(2) A–2, B–1
(3) A–1, B–1
(4) A–2, B–2
Explanation:
Cleistogamous flowers undergo self-pollination (1), whereas chasmogamous flowers may cross-pollinate (2). Correct match is (1).
9. Fill in the Blanks:
Flowers that remain closed and self-pollinate are called _______.
(1) Cleistogamous
(2) Chasmogamous
(3) Bisexual
(4) Unisexual
Explanation:
Cleistogamous flowers never open and always self-pollinate, ensuring reproduction without pollinators. Correct answer is (1).
10. Choose the Correct Statements:
(a) Cleistogamous flowers are always autogamous
(b) They never open
(c) They rely on insects for pollination
(d) They limit genetic diversity
Options:
(1) a, b, d
(2) a and c only
(3) b and c only
(4) all of the above
Explanation:
Cleistogamous flowers self-pollinate (a), remain closed (b), and limit genetic diversity (d). They do not rely on insects. Correct answer is (1).
Topic: Floral Formulae and Families
Subtopic: Matching Floral Formula with Families
Keyword Definitions:
Floral formula: A symbolic representation of flower structure showing calyx, corolla, androecium, and gynoecium.
Brassicaceae: Family with cruciform corolla and tetradynamous stamens.
Fabaceae: Family with papilionaceous corolla and diadelphous stamens.
Solanaceae: Family with epipetalous stamens and bicarpellary ovary.
Liliaceae: Monocot family with trimerous flowers and superior ovary.
Lead Question - 2021
Match Column - I with Column - II.
(a) ♂♀K(5)C1+2+(2)A(9)+1G1
(b) ♂♀K(5)C(5)A5G2
(c) ♂♀P(3+3)A3+3G(3)
(d) ♂♀K2+2C4A2+2G(2)
Column - II
(i) Brassicaceae
(ii) Liliaceae
(iii) Fabaceae
(iv) Solanaceae
(1) (a-i), (b-ii), (c-iii), (d-iv)
(2) (a-ii), (b-iii), (c-iv), (d-i)
(3) (a-iv), (b-iii), (c-i), (d-ii)
(4) (a-iii), (b-iv), (c-ii), (d-i)
Explanation: The correct answer is option (1). Formula (a) belongs to Fabaceae with diadelphous stamens. Formula (b) represents Solanaceae with pentamerous flowers. Formula (c) belongs to Liliaceae with trimerous flowers. Formula (d) represents Brassicaceae with tetradynamous stamens. Thus, (a-i), (b-ii), (c-iii), (d-iv) is the correct matching sequence.
Guessed Questions
1) In Brassicaceae, stamens are typically:
(1) Monadelphous
(2) Diadelphous
(3) Tetradynamous
(4) Polyandrous
Explanation: The correct answer is (3). Brassicaceae flowers show tetradynamous condition, where six stamens are present, four long and two short. This characteristic feature helps in identification of the family. Such floral adaptation ensures efficient pollination and is unique to the mustard family members.
2) In Fabaceae, the corolla is:
(1) Cruciform
(2) Papilionaceous
(3) Gamopetalous
(4) Rotate
Explanation: The correct answer is (2). Fabaceae members have papilionaceous corolla, composed of a standard, two wings, and a keel. This structure is specialized for pollination in legumes like pea and bean. The papilionaceous arrangement ensures proper landing platform and protection of reproductive structures.
3) Which feature is typical of Solanaceae?
(1) Polycarpellary ovary
(2) Epipetalous stamens
(3) Diadelphous condition
(4) Unilocular ovary
Explanation: The correct answer is (2). Solanaceae flowers have stamens attached to petals, called epipetalous stamens. This feature, along with bicarpellary syncarpous ovary and axile placentation, distinguishes the family. Examples include tomato, potato, and brinjal, which are widely cultivated food crops.
4) In Liliaceae, flowers are:
(1) Pentamerous
(2) Tetramerous
(3) Trimerous
(4) Dimerous
Explanation: The correct answer is (3). Liliaceae, being a monocot family, has trimerous flowers with floral parts in multiples of three. This is a key identifying feature of monocots. Members like onion and tulip display this arrangement. The ovary is superior and trilocular.
5) In Fabaceae, stamens are:
(1) Monadelphous
(2) Diadelphous
(3) Polyandrous
(4) Syngenesious
Explanation: The correct answer is (2). Fabaceae flowers typically have diadelphous stamens, where ten stamens are present, nine fused and one free. This condition supports pollination by providing mechanical aid. It is an important diagnostic feature for identifying this family among dicot plants.
6) Which of the following shows a cruciform corolla?
(1) Mustard
(2) Pea
(3) Potato
(4) Onion
Explanation: The correct answer is (1). Mustard, belonging to Brassicaceae, shows cruciform corolla where four free petals are arranged in the shape of a cross. This characteristic arrangement is distinctive for the family and aids in recognizing cruciferous vegetables such as radish, cabbage, and cauliflower.
7) Assertion (A): Solanaceae members have epipetalous stamens.
Reason (R): Stamens arise from the gynoecium.
(1) Both A and R are true, R explains A
(2) A true, R false
(3) A false, R true
(4) Both A and R false
Explanation: The correct answer is (2). In Solanaceae, stamens are epipetalous, meaning they are attached to petals, not arising from the gynoecium. Thus, assertion is correct but reason is false. This feature helps in pollination and is characteristic of the family.
8) Match the following:
(a) Brassicaceae → (i) Cruciform corolla
(b) Fabaceae → (ii) Papilionaceous corolla
(c) Solanaceae → (iii) Epipetalous stamens
(d) Liliaceae → (iv) Trimerous flowers
(1) a-i, b-ii, c-iii, d-iv
(2) a-ii, b-iv, c-i, d-iii
(3) a-iv, b-iii, c-ii, d-i
(4) a-iii, b-i, c-iv, d-ii
Explanation: The correct answer is (1). Brassicaceae has cruciform corolla, Fabaceae has papilionaceous corolla, Solanaceae has epipetalous stamens, and Liliaceae shows trimerous flowers. These diagnostic characters are essential for classifying plants into families based on their floral morphology.
9) Fill in the blank: The floral formula of Fabaceae is represented as __________.
(1) K5C1+2+(2)A9+1G1
(2) K(5)C(5)A5G2
(3) P3+3A3+3G(3)
(4) K2+2C4A2+2G(2)
Explanation: The correct answer is (1). Fabaceae has floral formula K5C1+2+(2)A9+1G1, where the papilionaceous corolla is represented as standard, wings, and keel, with diadelphous stamens and a monocarpellary ovary. This formula is diagnostic for the family, especially legumes like pea and bean.
10) Choose the correct statements:
(1) Brassicaceae has cruciform corolla.
(2) Fabaceae shows diadelphous stamens.
(3) Solanaceae flowers are pentamerous.
(4) Liliaceae has trimerous flowers.
(1) 1, 2, 3, and 4
(2) 1, 2, and 4 only
(3) 1 and 3 only
(4) 2 and 4 only
Explanation: The correct answer is (1). All statements are true: Brassicaceae has cruciform corolla, Fabaceae has diadelphous stamens, Solanaceae has pentamerous epipetalous flowers, and Liliaceae has trimerous flowers. These features serve as important diagnostic characteristics for classification of angiosperm families.
Topic: Sexual Reproduction
Subtopic: Gametic Fusion Processes
Keyword Definitions:
Plasmogamy: Fusion of the cytoplasm of two gametes.
Karyogamy: Fusion of nuclei of gametes after plasmogamy.
Saprophytes: Organisms obtaining nutrition from dead and decaying matter.
Heterocyst: Specialized cell in cyanobacteria for nitrogen fixation.
Lead Question - 2021
Which of the following statements is correct?
(1) Fusion of protoplasms between two motile or non-motile gametes is called plasmogamy.
(2) Organisms that depend on living plants are called saprophytes.
(3) Some of the organisms can fix atmospheric nitrogen in specialized cells called sheath cells.
(4) Fusion of two cells is called Karyogamy.
Explanation: The correct answer is option (1) because plasmogamy refers to cytoplasmic fusion of two gametes. Karyogamy specifically denotes nuclear fusion. Saprophytes live on dead matter, not living plants. Nitrogen fixation occurs in heterocysts, not sheath cells. Thus, plasmogamy is the accurate definition here, highlighting the initial stage in sexual reproduction.
Guessed Questions
1) In fungi, after plasmogamy but before karyogamy, the stage is:
(1) Diploid
(2) Dikaryotic
(3) Haploid
(4) Polyploid
Explanation: The correct answer is (2). After plasmogamy, nuclei from different gametes remain unfused, resulting in a dikaryotic stage. This is unique to fungi and persists until karyogamy occurs. It allows genetic variation and adaptation. This prolonged dikaryotic phase helps fungi survive under diverse environmental conditions before nuclear fusion.
2) Karyogamy results in:
(1) Diploid zygote
(2) Haploid gamete
(3) Dikaryon
(4) Spore mother cell
Explanation: The correct answer is (1). Karyogamy refers to the fusion of nuclei from two haploid gametes, forming a diploid zygote. This process is essential for sexual reproduction, leading to recombination and variation. The diploid stage formed undergoes meiosis later to restore haploid conditions in offspring.
3) Which organisms typically possess heterocysts?
(1) Blue-green algae
(2) Green algae
(3) Fungi
(4) Protozoa
Explanation: The correct answer is (1). Heterocysts are thick-walled cells present in cyanobacteria (blue-green algae) like Anabaena and Nostoc. They are specialized for nitrogen fixation, providing anaerobic conditions necessary for nitrogenase activity. These cells ensure survival and growth of cyanobacteria in nitrogen-deficient environments, playing a critical role in the nitrogen cycle.
4) In plants, saprophytes derive nutrition from:
(1) Living hosts
(2) Soil minerals only
(3) Dead and decaying matter
(4) Symbiotic association
Explanation: The correct answer is (3). Saprophytes feed on dead and decaying organic matter by secreting enzymes to decompose it. Examples include fungi like mushrooms. They recycle nutrients back to the ecosystem, making them vital decomposers. Unlike parasites, they do not harm living hosts while obtaining nutrition.
5) The dikaryotic phase is absent in:
(1) Basidiomycetes
(2) Ascomycetes
(3) Algae
(4) Higher fungi
Explanation: The correct answer is (3). Algae typically lack a prolonged dikaryotic phase. In fungi such as basidiomycetes and ascomycetes, the dikaryotic condition is common after plasmogamy, before karyogamy. This stage is absent in algae, which usually follow a simpler life cycle involving gamete fusion directly leading to zygote formation.
6) In sexual reproduction, plasmogamy is followed by:
(1) Syngamy
(2) Karyogamy
(3) Sporulation
(4) Fertilization
Explanation: The correct answer is (2). Plasmogamy is the fusion of gamete cytoplasm, while karyogamy is nuclear fusion. These sequential events complete syngamy or fertilization. Sporulation occurs later in some organisms. Thus, karyogamy follows plasmogamy to produce diploid nuclei that later undergo meiosis for gamete formation.
7) Assertion (A): Plasmogamy occurs before karyogamy in fungi.
Reason (R): Cytoplasmic fusion precedes nuclear fusion.
(1) A and R are true, R explains A
(2) A true, R false
(3) A false, R true
(4) A and R false
Explanation: The correct answer is (1). In fungi, plasmogamy (cytoplasmic fusion) occurs first, followed by karyogamy (nuclear fusion). This sequential process allows a dikaryotic stage in many fungi. The reason correctly explains the assertion. It ensures genetic recombination while maintaining adaptability before nuclear fusion finally occurs.
8) Match the following:
(a) Plasmogamy → (i) Fusion of cytoplasm
(b) Karyogamy → (ii) Fusion of nuclei
(c) Saprophyte → (iii) Nutrition from dead matter
(d) Heterocyst → (iv) Nitrogen fixation
(1) a-i, b-ii, c-iii, d-iv
(2) a-ii, b-i, c-iii, d-iv
(3) a-i, b-iii, c-iv, d-ii
(4) a-iv, b-i, c-ii, d-iii
Explanation: The correct answer is (1). Plasmogamy is cytoplasmic fusion, karyogamy is nuclear fusion, saprophytes feed on dead matter, and heterocysts specialize in nitrogen fixation. Each process or structure plays a vital role in biological cycles, reproduction, or ecosystem balance, reflecting the diversity of adaptations in living organisms.
9) Fill in the blanks: In fungi, __________ occurs first, followed by __________ during sexual reproduction.
(1) Karyogamy, plasmogamy
(2) Plasmogamy, karyogamy
(3) Syngamy, sporulation
(4) Sporulation, syngamy
Explanation: The correct answer is (2). In fungi, plasmogamy (cytoplasmic fusion) occurs first, creating a dikaryotic condition. Later, karyogamy (nuclear fusion) follows to complete fertilization. This unique sequence differentiates fungi from many organisms and allows them to maintain diversity and adaptability across varied ecological niches.
10) Choose the correct statements:
(1) Plasmogamy refers to cytoplasmic fusion.
(2) Karyogamy refers to nuclear fusion.
(3) Saprophytes depend on living hosts.
(4) Heterocysts are meant for nitrogen fixation.
(1) 1, 2, and 4
(2) 1 and 3 only
(3) 2 and 4 only
(4) 1, 2, 3, and 4
Explanation: The correct answer is (1). Plasmogamy involves cytoplasmic fusion, karyogamy involves nuclear fusion, and heterocysts are specialized for nitrogen fixation. Saprophytes feed on dead matter, not living hosts. Thus, statements 1, 2, and 4 are correct, while 3 is incorrect, highlighting differences among reproductive and nutritional strategies.
Topic: Pollination Biology
Subtopic: Pollen Viability
Keyword Definitions:
Pollen viability: Ability of pollen grains to remain alive and functional for fertilization.
Poaceae: Family of grasses, including wheat, rice, and maize.
Leguminosae: Plant family including beans, peas, and lentils.
Solanaceae: Family of plants including potato, tomato, and brinjal.
Rosaceae: Plant family including rose, apple, and strawberry.
Lead Question - 2021
In some members of which of the following pairs of families, pollen grains retain their viability for months after release?
(1) Poaceae ; Leguminosae
(2) Poaceae ; Solanaceae
(3) Rosaceae ; Leguminosae
(4) Poaceae ; Rosaceae
Explanation: Pollen viability varies greatly among plant families. Members of Poaceae and Rosaceae retain viable pollen grains for months, enhancing fertilization chances under varied conditions. This adaptation supports successful reproduction. Thus, the correct answer is (4) Poaceae; Rosaceae.
1. Pollen grains in which plant family commonly lose viability within a few minutes of release?
(1) Rice (Poaceae)
(2) Leguminosae
(3) Rosaceae
(4) Solanaceae
Explanation: In cereals like rice and wheat (Poaceae), pollen viability is very short, sometimes lasting only a few minutes, due to thin exine. This ensures rapid pollination in windy environments. Thus, the correct answer is (1) Rice (Poaceae).
2. In which plant family do pollen grains often remain viable for several months, aiding cross-pollination?
(1) Leguminosae
(2) Solanaceae
(3) Rosaceae
(4) Poaceae
Explanation: Rosaceae pollen grains can survive for long durations, sometimes months, ensuring successful pollination across seasons. This is crucial in fruit-bearing plants like apple and pear. Thus, the correct answer is (3) Rosaceae.
3. Assertion (A): In Rosaceae, pollen viability lasts for months.
Reason (R): Thick exine and protective compounds in pollen coat enhance longevity.
(1) Both A and R are true, and R is the correct explanation of A.
(2) Both A and R are true, but R is not the correct explanation of A.
(3) A is true, R is false.
(4) A is false, R is true.
Explanation: Pollen longevity in Rosaceae is due to structural adaptations like thick exine and sporopollenin presence. These ensure resistance against dehydration. Both assertion and reason are true, and R correctly explains A. Thus, the correct answer is (1).
4. Match the following families with approximate pollen viability duration:
A. Poaceae
B. Rosaceae
C. Solanaceae
D. Leguminosae
(1) A - Minutes, B - Months, C - Hours, D - Days
(2) A - Hours, B - Days, C - Months, D - Minutes
(3) A - Months, B - Hours, C - Days, D - Minutes
(4) A - Days, B - Months, C - Hours, D - Minutes
Explanation: Poaceae pollen lasts minutes, Rosaceae months, Solanaceae hours, and Leguminosae days. This variation ensures reproductive success adapted to pollination mechanisms. Thus, the correct answer is (1).
5. Fill in the blank:
Pollen grains of ___________ remain viable for months due to their thick exine and protective structures.
(1) Rice
(2) Rose
(3) Tomato
(4) Gram
Explanation: Rose belongs to Rosaceae, where pollen grains remain viable for months. Structural features like sporopollenin in the exine prevent desiccation and degradation, ensuring longer reproductive capacity. Thus, the correct answer is (2) Rose.
6. Which one of the following plants has the shortest pollen viability?
(1) Wheat
(2) Apple
(3) Tomato
(4) Gram
Explanation: Wheat, a member of Poaceae, has pollen viability lasting only a few minutes. This adaptation facilitates rapid wind pollination. Apple (Rosaceae), tomato (Solanaceae), and gram (Leguminosae) show longer viability compared to wheat. Thus, the correct answer is (1) Wheat.
7. Which of the following statements about pollen viability is correct?
(1) Poaceae pollen lasts months.
(2) Rosaceae pollen lasts months.
(3) Solanaceae pollen lasts days.
(4) Leguminosae pollen lasts minutes.
Explanation: Rosaceae pollen grains remain viable for months, while Poaceae lasts minutes, Solanaceae hours, and Leguminosae days. This diversity reflects reproductive adaptations in different ecological settings. Thus, the correct answer is (2) Rosaceae pollen lasts months.
8. Which adaptation ensures high pollen viability in Rosaceae family members?
(1) Thin exine
(2) Sporopollenin in exine
(3) Absence of coat
(4) Rapid hydration
Explanation: Sporopollenin in the exine of pollen grains is the toughest organic compound, preventing degradation and ensuring long-term viability. This feature allows Rosaceae pollen to survive months after release. Thus, the correct answer is (2) Sporopollenin in exine.
9. Choose the correct statements about pollen viability:
(1) Poaceae pollen lasts a few minutes.
(2) Rosaceae pollen lasts months.
(3) Solanaceae pollen lasts hours.
(4) Leguminosae pollen lasts days.
(1) 1, 2 and 3 only
(2) 2, 3 and 4 only
(3) 1, 2, 3 and 4
(4) 1 and 4 only
Explanation: Pollen viability differs among families: Poaceae – minutes, Rosaceae – months, Solanaceae – hours, Leguminosae – days. All given statements are correct. Thus, the correct answer is (3) 1, 2, 3 and 4.
10. In which of the following does pollen viability remain longest?
(1) Wheat
(2) Tomato
(3) Gram
(4) Apple
Explanation: Apple, belonging to Rosaceae, has pollen grains viable for months, ensuring cross-pollination and fruit set. Wheat, tomato, and gram show shorter viability. Thus, the correct answer is (4) Apple.
Topic: Pollination
Subtopic: Types of Pollination
Keyword Definitions:
Pollination: Transfer of pollen grains from anther to stigma.
Geitonogamy: Pollination between different flowers of the same plant.
Chasmogamy: Pollination in open flowers before fertilization.
Cleistogamy: Pollination in closed flowers without opening.
Xenogamy: Pollination between flowers of genetically different plants.
Lead Question - 2021
The term used for transfer of pollen grains from anthers of one plant to stigma of a different plant which, during pollination, brings genetically different types of pollen grains to stigma, is :
(1) Geitonogamy
(2) Chasmogamy
(3) Cleistogamy
(4) Xenogamy
Explanation: The correct answer is (4) Xenogamy. Xenogamy involves pollen transfer between flowers of different plants, ensuring genetic variation. Geitonogamy occurs within the same plant, cleistogamy in closed flowers, and chasmogamy in open flowers. Xenogamy is the only true cross-pollination type introducing genetic diversity. Thus, option (4) is correct.
Guessed Questions:
1. Self-pollination within the same flower is called:
(1) Autogamy
(2) Xenogamy
(3) Geitonogamy
(4) Cleistogamy
Explanation: The correct answer is (1) Autogamy. It occurs when pollen from the same flower fertilizes its ovules. This ensures seed formation without external agents but limits genetic diversity. Cleistogamy is a form of autogamy in closed flowers. Geitonogamy occurs between flowers of the same plant. Xenogamy is true cross-pollination.
2. Which pollination type ensures maximum genetic variation?
(1) Autogamy
(2) Geitonogamy
(3) Xenogamy
(4) Cleistogamy
Explanation: The correct answer is (3) Xenogamy. It ensures genetic variation because pollen comes from a different plant of the same species. Autogamy and geitonogamy involve self-pollination, producing limited diversity. Cleistogamy ensures reproduction but no genetic variation. Thus, xenogamy is essential for evolution and adaptability of plants.
3. Which agent is most commonly associated with xenogamy in flowering plants?
(1) Water
(2) Wind
(3) Insects
(4) Gravity
Explanation: The correct answer is (3) Insects. Insects are the most common agents of cross-pollination (xenogamy) as they carry pollen between flowers of different plants. Wind and water also help in some species, but insect pollination dominates among angiosperms due to co-evolution. Gravity is rarely an agent of pollination.
4. Pollination occurring in unopened flowers is termed:
(1) Cleistogamy
(2) Chasmogamy
(3) Geitonogamy
(4) Xenogamy
Explanation: The correct answer is (1) Cleistogamy. Cleistogamous flowers remain closed and undergo self-pollination, ensuring reproductive assurance even in absence of pollinators. Chasmogamy occurs in open flowers, geitonogamy between flowers of the same plant, and xenogamy between different plants. Cleistogamy guarantees seed formation but reduces genetic diversity.
5. In geitonogamy, pollen grains come from:
(1) Same flower
(2) Different flowers of the same plant
(3) Different plants of the same species
(4) Different species
Explanation: The correct answer is (2) Different flowers of the same plant. Geitonogamy requires pollinators but results genetically similar to self-pollination. It differs from autogamy (same flower) and xenogamy (different plants). Though it involves agents, genetic variation is absent, since both flowers belong to the same individual plant.
6. Which type of pollination is evolutionarily most advantageous?
(1) Autogamy
(2) Geitonogamy
(3) Cleistogamy
(4) Xenogamy
Explanation: The correct answer is (4) Xenogamy. It introduces genetic recombination, increasing adaptability and survival. Autogamy, cleistogamy, and geitonogamy ensure reproduction but lack genetic variability. Evolution depends on variation, making xenogamy the most beneficial type for natural selection and long-term plant survival in changing environments.
7. Assertion (A): Cleistogamous flowers are always autogamous.
Reason (R): Cleistogamous flowers remain closed and facilitate only cross-pollination.
(1) Both A and R are true, R is correct explanation of A
(2) Both A and R are true, R is not correct explanation of A
(3) A is true, R is false
(4) A is false, R is true
Explanation: The correct answer is (3) A is true, R is false. Cleistogamous flowers are indeed autogamous because they self-pollinate in closed buds. However, they do not facilitate cross-pollination. Therefore, the reason is false, while the assertion is true.
8. Match the following pollination types with their descriptions:
A. Autogamy 1. Same flower
B. Geitonogamy 2. Different flowers of same plant
C. Xenogamy 3. Different plants
(1) A-1, B-2, C-3
(2) A-2, B-1, C-3
(3) A-1, B-3, C-2
(4) A-3, B-2, C-1
Explanation: The correct answer is (1) A-1, B-2, C-3. Autogamy refers to pollination within the same flower, geitonogamy between flowers of the same plant, and xenogamy between flowers of different plants. This classification distinguishes the modes of pollination based on the origin of pollen grains.
9. Fill in the blank: Pollination by water is termed ________.
(1) Anemophily
(2) Hydrophily
(3) Zoophily
(4) Entomophily
Explanation: The correct answer is (2) Hydrophily. When water acts as the pollinating agent, it is called hydrophily. Anemophily refers to wind pollination, zoophily to animal-mediated pollination, and entomophily specifically to insect-mediated pollination. Hydrophily is less common but occurs in aquatic plants such as Vallisneria and Hydrilla.
10. Choose the correct statements:
(a) Xenogamy increases genetic diversity.
(b) Geitonogamy involves genetically different plants.
(c) Cleistogamy ensures pollination without agents.
(d) Autogamy occurs in the same flower.
Options:
(1) a, b, c
(2) a, c, d
(3) b, c, d
(4) a, b, d
Explanation: The correct answer is (2) a, c, d. Xenogamy increases genetic diversity, cleistogamy ensures pollination without agents, and autogamy occurs within the same flower. Geitonogamy, however, involves the same plant, not different ones. Thus, statements a, c, and d are correct together.
Topic: Embryo Sac Structure
Subtopic: Mature Angiosperm Embryo Sac
Keyword Definitions:
Embryo sac: Female gametophyte of angiosperms, developing within the ovule and participating in fertilization.
Angiosperm: Flowering plants producing seeds enclosed in fruits.
7-nucleate: Containing seven nuclei.
8-celled: Comprising eight distinct cells, including egg, synergids, antipodals, and central cell.
Synergids: Two cells flanking the egg cell, aiding in fertilization.
Antipodals: Three cells at the chalazal end of the embryo sac, usually nutritive.
Central cell: Contains two polar nuclei that fuse with a sperm nucleus to form endosperm.
Mature embryo sac: Ready for fertilization, fully differentiated with distinct cell types.
Lead Question - 2021
A typical angiosperm embryo sac at maturity is:
(1) 7-nucleate and 8-celled
(2) 7-nucleate and 7-celled
(3) 8-nucleate and 8-celled
(4) 8-nucleate and 7-celled
Explanation: The correct answer is (1) 7-nucleate and 8-celled. The mature embryo sac has seven nuclei distributed in eight cells: one egg cell, two synergids, three antipodals, and one central cell with two polar nuclei. This structure is characteristic of the Polygonum type of angiosperm embryo sac, ensuring fertilization and endosperm formation.
Guessed Questions:
1) Single Correct Answer: The central cell in an embryo sac contains:
(1) One nucleus
(2) Two polar nuclei
(3) Three nuclei
(4) None
Explanation: The correct answer is (2) Two polar nuclei. The central cell fuses with one sperm during double fertilization to form triploid endosperm. Other options are incorrect as they do not represent the true nuclear composition of the central cell.
2) Single Correct Answer: Number of synergids in a mature embryo sac is:
(1) One
(2) Two
(3) Three
(4) Four
Explanation: The correct answer is (2) Two. Synergids are positioned at the micropylar end, assisting in guiding the pollen tube. They are distinct from egg and antipodal cells, ensuring proper fertilization.
3) Single Correct Answer: Number of antipodal cells in a mature angiosperm embryo sac:
(1) One
(2) Two
(3) Three
(4) Four
Explanation: The correct answer is (3) Three. Antipodals are located at the chalazal end and are usually nutritive. Their number is three in the Polygonum type embryo sac, contributing to the overall eight-cell structure.
4) Assertion (A): Mature embryo sac is 7-nucleate and 8-celled.
Reason (R): Polar nuclei remain unfused until fertilization.
(1) Both A and R true, R explains A
(2) Both A and R true, R does not explain A
(3) A true, R false
(4) A false, R true
Explanation: Correct answer is (1). The mature embryo sac is 7-nucleate and 8-celled. The two polar nuclei in the central cell remain unfused until a sperm nucleus enters for double fertilization, explaining the nucleate and cellular arrangement.
5) Single Correct Answer: The egg apparatus in an embryo sac consists of:
(1) Egg cell only
(2) Egg cell and two synergids
(3) Egg cell and three antipodals
(4) Two polar nuclei
Explanation: The correct answer is (2) Egg cell and two synergids. This arrangement forms the micropylar end of the embryo sac, essential for receiving the pollen tube and facilitating fertilization.
6) Single Correct Answer: The type of embryo sac in most angiosperms is:
(1) Allium type
(2) Polygonum type
(3) Oenothera type
(4) Fritillaria type
Explanation: Correct answer is (2) Polygonum type. It is the most common type of embryo sac, consisting of seven nuclei and eight cells, ensuring proper fertilization and endosperm development.
7) Matching Type: Match cell types with functions in the embryo sac:
List-I List-II
(a) Egg cell (i) Fertilization
(b) Synergids (ii) Guide pollen tube
(c) Antipodals (iii) Nutritive
(d) Central cell (iv) Forms endosperm
Explanation: Correct answer: (a) i, (b) ii, (c) iii, (d) iv. Egg cell fuses with sperm to form zygote. Synergids guide pollen tube. Antipodals provide nutrition. Central cell with two polar nuclei forms triploid endosperm after fertilization.
8) Single Correct Answer: Number of cells at micropylar end of mature embryo sac:
(1) Three
(2) Four
(3) Five
(4) Two
Explanation: Correct answer is (1) Three. The micropylar end consists of one egg cell and two synergids, forming the egg apparatus that interacts with the pollen tube for fertilization.
9) Fill in the blank: The central cell contains ______ polar nuclei before fertilization.
(1) One
(2) Two
(3) Three
(4) None
Explanation: Correct answer is (2) Two. The two polar nuclei remain separate until fertilization by a sperm nucleus, which forms the triploid endosperm in angiosperms.
10) Choose the correct statements:
(a) Mature embryo sac has seven nuclei.
(b) It has eight cells.
(c) Egg apparatus includes synergids.
(d) Central cell contains two polar nuclei.
Options:
(1) a, b, c, d
(2) a, b, c
(3) b, c, d
(4) a, c, d
Explanation: Correct answer is (1). The mature embryo sac has seven nuclei and eight cells. Egg apparatus includes synergids, and the central cell has two polar nuclei, confirming all four statements are accurate for angiosperm reproduction.
Topic: Types of Plants Based on Sex
Subtopic: Monoecious and Dioecious Plants
Keyword Definitions:
Monoecious: Plants in which both male and female reproductive organs are present on the same individual.
Dioecious: Plants in which male and female reproductive organs occur on separate individuals.
Chara: A green alga, usually dioecious, with separate male and female gametangia.
Marchantia polymorpha: A liverwort, typically dioecious, with distinct male and female plants.
Cycas circinalis: A gymnosperm that is dioecious, producing male and female cones on separate plants.
Carica papaya: A flowering plant that may be monoecious, having both male and female flowers on the same plant.
Male Flower: Produces pollen and stamens.
Female Flower: Produces ovules and carpels.
Lead Question - 2021
Which of the following plants is monoecious?
(1) Chara
(2) Marchantia polymorpha
(3) Cycas circinalis
(4) Carica papaya
Explanation: The correct answer is (4) Carica papaya. Monoecious plants bear both male and female flowers on the same individual, allowing self-pollination or cross-pollination. Chara, Marchantia, and Cycas are dioecious, producing male and female reproductive structures on separate individuals, preventing self-fertilization.
Guessed Questions:
1) Single Correct Answer: Which plant is dioecious?
(1) Carica papaya
(2) Cycas circinalis
(3) Maize
(4) Cucurbita
Explanation: The correct answer is (2) Cycas circinalis. This gymnosperm has male and female cones on separate plants. Dioecious plants produce male and female reproductive structures on different individuals, ensuring cross-pollination and genetic diversity.
2) Single Correct Answer: Monoecious plants include:
(1) Maize
(2) Carica papaya
(3) Cycas
(4) Marchantia
Explanation: The correct answer is (2) Carica papaya. In monoecious plants like papaya, both male and female flowers grow on the same plant, facilitating reproduction, unlike dioecious plants where male and female structures are on separate individuals.
3) Single Correct Answer: In monoecious plants, male and female flowers are:
(1) On separate plants
(2) On the same plant
(3) Absent
(4) Alternating yearly
Explanation: The correct answer is (2) On the same plant. Monoecious plants bear both male (staminate) and female (pistillate) flowers on the same individual, allowing potential self-pollination or cross-pollination, depending on flower arrangement and pollinator activity.
4) Assertion (A): Carica papaya can self-pollinate.
Reason (R): It is monoecious, bearing both male and female flowers.
(1) Both A and R true, R explains A
(2) Both A and R true, R does not explain A
(3) A true, R false
(4) A false, R true
Explanation: The correct answer is (1). Carica papaya is monoecious, bearing both male and female flowers on the same plant. This allows self-pollination if pollen reaches the female flower, but cross-pollination may still occur via insects, enhancing genetic diversity.
5) Matching Type: Match plants with sexual condition.
List-I List-II
(a) Chara (i) Monoecious
(b) Carica papaya (ii) Dioecious
(c) Cycas (iii) Dioecious
(d) Marchantia (iv) Dioecious
Explanation: Correct answer: (a) ii, (b) i, (c) iii, (d) iv. Chara, Cycas, and Marchantia are dioecious with male and female organs on separate individuals, while Carica papaya is monoecious with both flower types on the same plant, illustrating plant sexual diversity.
6) Single Correct Answer: Male and female flowers on separate plants occur in:
(1) Carica papaya
(2) Chara
(3) Maize
(4) Wheat
Explanation: The correct answer is (2) Chara. Chara is dioecious, producing male and female gametangia on separate individuals. This separation prevents self-fertilization and encourages cross-fertilization for genetic variation.
7) Single Correct Answer: In monoecious plants, pollination may occur via:
(1) Only wind
(2) Only insects
(3) Wind or insects
(4) Neither
Explanation: The correct answer is (3) Wind or insects. Monoecious plants like Carica papaya can utilize wind or insect vectors for pollen transfer between male and female flowers on the same plant or between different plants.
8) Single Correct Answer: Dioecious plants prevent self-fertilization because:
(1) Flowers are unisexual on same plant
(2) Male and female flowers on separate plants
(3) Flowers are bisexual
(4) Pollen is non-viable
Explanation: The correct answer is (2). Dioecious plants like Cycas circinalis have male and female flowers on separate plants, making self-fertilization impossible and promoting cross-pollination for increased genetic diversity.
9) Fill in the blank: Plants with both male and female flowers on one individual are _______.
(1) Dioecious
(2) Monoecious
(3) Bisexual
(4) Polygamous
Explanation: The correct answer is (2) Monoecious. Monoecious plants have male and female flowers on the same individual, allowing reproduction without a separate plant, unlike dioecious plants where male and female flowers are on different plants.
10) Choose the correct statements:
(a) Carica papaya is monoecious.
(b) Cycas is dioecious.
(c) Chara is monoecious.
(d) Marchantia is dioecious.
Options:<
Topic: Flower Structure
Subtopic: Stamen Types
Keyword Definitions:
Diadelphous Stamens: Stamens united by filaments into two groups, typically one long and one short bundle.
Citrus: A genus of flowering plants with characteristic diadelphous stamens in some species.
Pea: Leguminous plant (Pisum sativum) with diadelphous stamens arranged in 9+1 formation.
China Rose: Hibiscus rosa-sinensis; a flower with monadelphous stamens where all filaments are fused into a tube.
Stamen: Male reproductive organ of a flower, consisting of anther and filament.
Filament: The stalk supporting the anther in stamens.
Anther: Part of stamen producing pollen grains.
Monadelphous: Stamens fused into a single bundle by their filaments.
Lead Question - 2021
Diadelphous stamens are found in:
(1) Citrus
(2) Pea
(3) China rose and citrus
(4) China rose
Explanation: The correct answer is (2) Pea. In pea flowers, the stamens are diadelphous, with nine filaments united to form a tube and one free filament. This arrangement facilitates pollination and distinguishes peas from flowers with monadelphous stamens like China rose or other species.
Guessed Questions:
1) In which type of stamen all filaments are fused into a single bundle?
(1) Diadelphous
(2) Monadelphous
(3) Polyadelphous
(4) Free stamens
Explanation: The correct answer is (2) Monadelphous. In monadelphous stamens, all filaments are fused into a single tube, as seen in China rose, supporting efficient pollen transfer while maintaining structural integrity of the staminal column.
2) Assertion (A): Diadelphous stamens are characteristic of leguminous plants.
Reason (R): They have stamens in two groups with one free filament and others fused.
(1) Both A and R true, R explains A
(2) Both A and R true, R does not explain A
(3) A true, R false
(4) A false, R true
Explanation: The correct answer is (1). Pea and other legumes exhibit diadelphous stamens. Nine filaments fuse into a tube, and one remains free, facilitating pollen release and transfer. This arrangement is distinctive for the Fabaceae family and aids identification of leguminous flowers.
3) Which flower has stamens completely free and not fused?
(1) Pea
(2) China rose
(3) Lily
(4) Citrus
Explanation: The correct answer is (3) Lily. Lily flowers have free stamens, with each filament supporting its own anther independently. This contrasts with diadelphous or monadelphous arrangements where filaments are partially or fully fused.
4) Fill in the blank: In pea, the diadelphous stamens have ______ filaments fused into a tube and one free.
(1) 8
(2) 9
(3) 10
(4) 11
Explanation: The correct answer is (2) 9. In pea flowers, nine staminal filaments fuse into a tube surrounding the pistil, and one remains free. This 9+1 arrangement is characteristic of diadelphous stamens in leguminous plants.
5) Which of the following flowers exhibits polyadelphous stamens?
(1) China rose
(2) China berry (Melia azedarach)
(3) Pea
(4) Lily
Explanation: The correct answer is (2) China berry. Polyadelphous stamens are fused into more than two bundles, as seen in Melia azedarach. This differs from diadelphous (two bundles) or monadelphous (single bundle) arrangements and helps in floral classification.
6) Which part of the stamen produces pollen?
(1) Filament
(2) Anther
(3) Ovary
(4) Petal
Explanation: The correct answer is (2) Anther. The anther is the terminal part of the stamen where microsporangia develop and release pollen grains. Filaments provide support, but pollen formation occurs exclusively in anthers.
7) Choose the correct statements:
a. Diadelphous stamens are typical in legumes.
b. China rose has monadelphous stamens.
c. Pea stamens have all filaments free.
d. Polyadelphous stamens form more than two bundles.
(1) a, b, d
(2) a, c
(3) b, c
(4) a, b, c, d
Explanation: The correct answer is (1) a, b, d. Diadelphous stamens occur in legumes like pea, China rose has monadelphous stamens, and polyadelphous stamens form more than two bundles. Statement c is incorrect because pea has one free filament and nine fused, not all free.
8) Assertion (A): Monadelphous stamens form a tube around the pistil.
Reason (R): All filaments are united into a single bundle.
(1) Both A and R true, R explains A
(2) Both A and R true, R does not explain A
(3) A true, R false
(4) A false, R true
Explanation: The correct answer is (1). In China rose, monadelphous stamens form a tube around the pistil as all filaments are fused. This arrangement enhances pollen presentation to pollinators while maintaining structural support around the female organ.
9) Matching Type: Match the stamen type with example flower.
List-I List-II
(a) Diadelphous (i) China rose
(b) Monadelphous (ii) Pea
(c) Polyadelphous (iii) China berry
(d) Free stamens (iv) Lily
Select correct answer:
(a) (b) (c) (d)
(1) ii, i, iii, iv
(2) i, ii, iii, iv
(3) ii, iii, i, iv
(4) iv, i, ii, iii
Explanation
Subtopic: Pollination Mechanisms
Keyword Definitions:
Wind-pollination (Anemophily): Transfer of pollen from anthers to stigma by wind.
Stamens: Male reproductive organ of a flower producing pollen grains.
Stigma: Part of pistil that receives pollen.
Ovules: Structures inside ovary that develop into seeds after fertilization.
Pollen grains: Male gametophytes that carry sperm cells to ovules.
Non-sticky pollen: Pollen that does not adhere easily, suitable for wind transport.
Lead Question - 2020 (COVID Reexam)
Which of the following is incorrect for wind-pollinated plants?
1. Well exposed stamens and stigma
2. Many ovules in each ovary
3. Flowers are small and not brightly colored
4. Pollen grains are light and non-sticky
Explanation: Wind-pollinated plants have exposed stamens and stigma, small inconspicuous flowers, and light, non-sticky pollen grains. Typically, each ovary contains few ovules to increase efficiency of fertilization. Therefore, statement 2 is incorrect. Answer: Option 2.
1. Single correct answer MCQ:
Which feature is advantageous for wind pollination?
1. Brightly colored petals
2. Sticky pollen
3. Exposed stamens
4. Fewer flowers
Explanation: Exposed stamens allow pollen to be easily carried by wind to the stigma of other flowers. Bright petals and sticky pollen are adaptations for insect pollination. Efficient wind pollination requires numerous flowers with non-sticky pollen. Answer: Option 3.
2. Single correct answer MCQ:
Wind-pollinated flowers generally have:
1. Large nectar rewards
2. Small inconspicuous petals
3. Strong scent
4. Sticky pollen
Explanation: Wind-pollinated flowers are small and inconspicuous, lacking bright colors, scent, or nectar. Pollen is lightweight and non-sticky for efficient dispersal. Large petals and scent attract insects, which is unnecessary for anemophilous plants. Answer: Option 2.
3. Single correct answer MCQ:
Pollen of wind-pollinated plants is:
1. Heavy and sticky
2. Light and non-sticky
3. Released at night only
4. Encased in nectar
Explanation: Wind-pollinated plants produce light, non-sticky pollen to facilitate airborne transport. Heavy or sticky pollen would settle quickly and reduce pollination efficiency. No nectar is present as insects are not involved. Answer: Option 2.
4. Single correct answer MCQ:
Stigmas of wind-pollinated plants are usually:
1. Small and smooth
2. Large and feathery
3. Sticky and bright
4. Hidden inside petals
Explanation: Stigmas are large and feathery in wind-pollinated plants to increase surface area for catching airborne pollen grains. Small or hidden stigmas reduce pollination efficiency. Sticky stigmas are common in insect-pollinated flowers. Answer: Option 2.
5. Single correct answer MCQ:
Wind pollination is most effective in plants with:
1. Few flowers
2. Dense foliage
3. Tall and exposed flowers
4. Nectar-rich flowers
Explanation: Tall and exposed flowers facilitate dispersal of pollen by wind. Dense foliage can block wind, and few flowers reduce pollen availability. Nectar-rich flowers attract insects, not wind. This adaptation maximizes cross-pollination. Answer: Option 3.
6. Single correct answer MCQ:
Number of ovules in wind-pollinated flowers is usually:
1. Many to ensure seed formation
2. Few for efficiency
3. None
4. Random
Explanation: Wind-pollinated flowers typically have few ovules per ovary to conserve resources and increase fertilization efficiency, as pollen transfer is less targeted than in insect-pollinated flowers. Answer: Option 2.
7. Assertion-Reason MCQ:
Assertion (A): Pollen grains are non-sticky in wind-pollinated plants.
Reason (R): Non-sticky pollen can be easily carried by wind.
1. Both A and R true, R is correct explanation
2. Both A and R true, R not correct explanation
3. A true, R false
4. A false, R true
Explanation: Non-sticky, lightweight pollen facilitates dispersal by wind, increasing pollination chances. Both assertion and reason are true, and reason explains assertion accurately. Answer: Option 1.
8. Matching Type MCQ:
Column I Column II
(a) Stigma (i) Feathery
(b) Petals (ii) Small and inconspicuous
(c) Pollen grains (iii) Light and non-sticky
(d) Flowers (iv) Tall and exposed
1. (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv)
2. (a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)
3. (a)-(iii), (b)-(iv), (c)-(i), (d)-(ii)
4. (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)
Explanation: Stigmas are feathery to catch pollen, petals are small and inconspicuous, pollen grains light and non-sticky, flowers tall and exposed for efficient wind pollination. Correct matching: (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv). Answer: Option 1.
9. Fill in the blanks:
Wind-pollinated flowers have ______ petals and ______ pollen.
1. Bright, sticky
2. Small, non-sticky
3. Large, heavy
4. Colorful, adhesive
Explanation: Small inconspicuous petals reduce resource expenditure, while non-sticky pollen is light for wind dispersal. This adaptation ensures pollination without insect vectors. Answer: Option 2.
10. Choose correct statements:
(a) Wind-pollinated flowers are bright and fragrant.
(b) Pollen is light and non-sticky.
(c) Stigmas are feathery.
(d) Many ovules are present for efficiency.
1. b and c only
2. a and d only
3. a, b, c
4. All correct
Explanation: Wind-pollinated flowers are inconspicuous, with light non-sticky pollen and feathery stigmas. Many ovules are not typical; usually few are present to increase fertilization efficiency. Therefore, correct statements are b and c only. Answer: Option 1.
Topic: Asexual Reproduction
Subtopic: Vegetative Propagation
Keyword Definitions:
Vegetative Propagation: Type of asexual reproduction using vegetative parts like stem, root, or leaf to form new plants.
Agave: Xerophytic plant that reproduces vegetatively through bulbils.
Bulbil: Small, bulb-like structure that develops on the parent plant and gives rise to new plants.
Rhizome: Underground stem that propagates plants like ginger and turmeric.
Offset: Short lateral shoot that helps water hyacinth multiply rapidly.
Eye: Vegetative bud found on potato tubers for propagation.
Lead Question - 2020 (COVID Reexam)
Vegetative propagule in Agave is as:
1. Rhizome
2. Bulbil
3. Offset
4. Eye
Explanation: In Agave, vegetative propagation occurs through bulbils. These are small bulb-like structures that detach and grow into new plants. Rhizome is used by ginger, offset by water hyacinth, and eye in potato. Thus, the propagule in Agave is bulbil. Answer: Option 2.
1. Which plant propagates through rhizome?
1. Potato
2. Ginger
3. Agave
4. Bryophyllum
Explanation: Ginger propagates vegetatively through rhizomes. Rhizomes are underground stems with nodes and buds that grow into new plants. Potato uses eyes, Agave uses bulbils, and Bryophyllum uses leaf buds. Answer: Option 2.
2. In water hyacinth, the mode of vegetative propagation is:
1. Runner
2. Offset
3. Sucker
4. Tuber
Explanation: Water hyacinth propagates through offsets, which are short lateral branches with nodes that develop roots and new plants. This makes it invasive and called the “terror of Bengal.” Answer: Option 2.
3. Vegetative reproduction in potato occurs through:
1. Rhizome
2. Bulbil
3. Eye
4. Offset
Explanation: Potato tubers propagate vegetatively through eyes, which are axillary buds present on tuber surface. These buds sprout to form new plants. Rhizomes and bulbils belong to other plants. Answer: Option 3.
4. Assertion (A): Bryophyllum reproduces vegetatively through leaf buds.
Reason (R): Adventitious buds on leaf margins of Bryophyllum develop into new plants.
1. Both A and R are true, R is correct explanation
2. Both A and R are true, R not correct explanation
3. A true, R false
4. A false, R true
Explanation: Bryophyllum reproduces by leaf buds formed along leaf margins. These buds detach, fall on soil, and develop into new plants. Thus both assertion and reason are true, with reason explaining assertion correctly. Answer: Option 1.
5. Match the following:
Column I Column II
(a) Agave (i) Eye
(b) Potato (ii) Offset
(c) Ginger (iii) Bulbil
(d) Water hyacinth (iv) Rhizome
1. (a)-(iii), (b)-(i), (c)-(iv), (d)-(ii)
2. (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii)
3. (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv)
4. (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii)
Explanation: Agave uses bulbil, potato uses eye, ginger uses rhizome, and water hyacinth uses offset for vegetative propagation. Correct matching is option 1.
6. Fill in the blank:
________ is known as the “Terror of Bengal” because of rapid propagation.
1. Agave
2. Water hyacinth
3. Bryophyllum
4. Potato
Explanation: Water hyacinth multiplies rapidly by offsets and chokes water bodies, causing oxygen depletion and harming aquatic life. Therefore, it is called the “Terror of Bengal.” Answer: Option 2.
7. Choose the correct statements:
(a) Ginger propagates through rhizomes.
(b) Potato propagates through bulbils.
(c) Agave propagates through bulbils.
(d) Bryophyllum propagates through leaf buds.
1. a, c, d only
2. b and c only
3. a and b only
4. a, b, c and d
Explanation: Ginger propagates through rhizome, Agave through bulbils, and Bryophyllum through leaf buds. Potato does not use bulbils but eyes. Therefore, correct statements are a, c, d. Answer: Option 1.
8. Vegetative reproduction in onion is carried out by:
1. Corm
2. Bulb
3. Rhizome
4. Runner
Explanation: Onion reproduces vegetatively through bulbs, which are underground modified stems surrounded by fleshy scales. They sprout into new plants when favorable. Corm belongs to gladiolus, rhizome to ginger, runner to grass. Answer: Option 2.
9. Which vegetative propagule is used by Eichhornia?
1. Offset
2. Runner
3. Corm
4. Bulbil
Explanation: Eichhornia, also called water hyacinth, propagates vegetatively by offsets. This helps rapid spread in aquatic ecosystems, making it invasive. Answer: Option 1.
10. In which plant are adventitious buds present on leaf margins?
1. Bryophyllum
2. Onion
3. Ginger
4. Agave
Explanation: Bryophyllum leaves have adventitious buds along leaf margins that develop into new plants when detached. This is a unique vegetative propagation method in Bryophyllum. Answer: Option 1.
Topic: Families
Subtopic: Liliaceae
Keywords
• Floral Formula – A symbolic representation of flower structure.
• Actinomorphic – Radial symmetry.
• Perianth – Undifferentiated calyx and corolla.
• Epigynous – Ovary below floral whorls.
• Syncarpous – Fused carpels.
Lead Question – 2020 (COVID Reexam)
Which of the following is the correct floral formula of Liliaceae?
1) % ⚥ P3+3 A3+3 G̲(3)
2) ⚥ K(5) C(5) A5 G̲(2)
3) Br ⚥ P(3+3) A3+3 G(3)
4) ⚥ K(5) C(5) A5 G(2)
Explanation: The correct floral formula of Liliaceae is ⚥ P3+3 A3+3 G̲(3). Flowers are actinomorphic, trimerous, perianth with six tepals, six stamens, and tricarpellary syncarpous ovary. The family shows superior ovary condition. Hence, option 1 is correct.
Question 2
Which type of ovary is present in Liliaceae family?
1) Epigynous
2) Hypogynous
3) Perigynous
4) None
Explanation: Flowers of Liliaceae are hypogynous with superior ovary. The perianth and stamens are attached below the ovary. Hence, the correct answer is option 2.
Question 3
Leaves of Liliaceae are usually:
1) Compound and alternate
2) Simple, parallel venation
3) Pinnately compound
4) Palmately compound
Explanation: Liliaceae has simple leaves with parallel venation, a key monocot feature. This helps differentiate them from dicots with reticulate venation. Correct answer is option 2.
Question 4
Which inflorescence is common in Liliaceae?
1) Raceme
2) Umbel
3) Spike
4) Capitulum
Explanation: The family shows racemose type, often umbel. Members like Allium exhibit umbellate clusters. Hence, option 2 is correct.
Question 5
Assertion (A): Flowers of Liliaceae are actinomorphic. Reason (R): They possess bilateral symmetry.
1) Both A and R are true, R explains A
2) Both A and R are true, R does not explain A
3) A is true, R is false
4) A is false, R is true
Explanation: Liliaceae flowers are actinomorphic due to radial symmetry, not bilateral. Assertion true, Reason false. Hence option 3 is correct.
Question 6
Match the following: A. Tepals – 6 B. Stamens – 6 C. Carpels – 3 D. Placentation – Axile
1) A1 B2 C3 D4
2) A2 B3 C1 D4
3) A6 B6 C3 D1
4) A4 B6 C2 D3
Explanation: In Liliaceae, there are six tepals, six stamens, three fused carpels, and axile placentation. Thus, correct matching corresponds to option 3.
Question 7
Fill in the blank: Ovary of Liliaceae is ______.
1) Tricarpellary, syncarpous, superior, axile placentation
2) Bicarpellary, syncarpous, inferior
3) Monocarpellary
4) Polycarpellary
Explanation: Ovary of Liliaceae is tricarpellary, syncarpous, superior with axile placentation. Hence, option 1 is correct.
Question 8
Choose the correct statements: 1) Liliaceae belongs to monocots. 2) Seeds are endospermic. 3) Perianth present instead of distinct calyx and corolla. 4) All the above.
Explanation: All statements are true: monocot family, seeds endospermic, and perianth with tepals instead of calyx and corolla. Correct answer is option 4.
Question 9
Which medicinal plant belongs to Liliaceae?
1) Aloe vera
2) Tulsi
3) Neem
4) Hibiscus
Explanation: Aloe vera, widely used in medicine and cosmetics, belongs to Liliaceae. Tulsi, Neem, and Hibiscus belong to other families. Answer is option 1.
Question 10
Pollination in Liliaceae is mostly:
1) Anemophily
2) Entomophily
3) Hydrophily
4) Zoophily
Explanation: Pollination in Liliaceae is mainly by insects (entomophily), due to showy flowers and nectar. Hence option 2 is correct.
Question 11
Fruit type of Liliaceae members is usually:
1) Capsule
2) Drupe
3) Berry
4) Nut
Explanation: The fruit in Liliaceae is typically a capsule, derived from a tricarpellary syncarpous ovary. Hence, option 1 is correct.
Topic: Flower Structure
Subtopic: Position of Floral Parts
Keyword Definitions:
Gynoecium: Female reproductive part of a flower, consisting of one or more carpels.
Thalamus: Receptacle; the expanded tip of a pedicel where floral organs are attached.
Ovary: Part of gynoecium containing ovules, develops into fruit after fertilization.
Floral parts: Sepals, petals, stamens, and carpels collectively form the flower.
Hypogynous flower: Gynoecium at highest position; other parts below it.
Perigynous flower: Margins of thalamus grow upward forming a cup; ovary is central.
Epigynous flower: Ovary inferior; other floral parts arise above the ovary.
Carpel: Unit of gynoecium enclosing ovules.
Sepals: Outer whorl of floral parts, usually green and protective.
Petals: Inner whorl, often colorful to attract pollinators.
Lead Question - 2020 (COVID Reexam)
Correct position of floral parts over thalamus in the mustard plant is :
1. Gynoecium occupies the highest position, while the other parts are situated below it.
2. Margin of the thalamus grows upward, enclosing the ovary completely, and other parts arise below the ovary.
3. Gynoecium is present in the center and other parts cover it partially.
4. Gynoecium is situated in the center, and other parts of the flower are located at the rim of the thalamus, at the same level.
Explanation: Mustard plant has a hypogynous flower where the gynoecium (carpels) occupies the highest position on the thalamus. Sepals, petals, and stamens arise below the ovary. This ensures the ovary remains superior. Correct answer is option (1) Gynoecium occupies the highest position, while the other parts are situated below it.
Guessed Questions:
1. Type of flower in mustard plant is:
(1) Epigynous
(2) Hypogynous
(3) Perigynous
(4) None of these
Explanation: Mustard flower is hypogynous with a superior ovary. Sepals, petals, and stamens arise below the ovary. Epigynous and perigynous flowers have inferior and half-inferior ovary respectively. Correct answer is option (2) Hypogynous.
2. Ovary position in hypogynous flower is:
(1) Superior
(2) Inferior
(3) Half-inferior
(4) Central
Explanation: In hypogynous flowers, gynoecium is at the top of thalamus and other parts arise below. Ovary remains above attachment of sepals, petals, and stamens, making it superior. Correct answer is option (1) Superior.
3. Stamens in mustard flower are located:
(1) Above the ovary
(2) Below the ovary
(3) Around the ovary
(4) Mixed with petals
Explanation: In hypogynous flowers like mustard, stamens arise below the ovary along with petals and sepals. This ensures the ovary is superior and not enclosed. Correct answer is option (2) Below the ovary.
4. Sepals and petals in mustard flower are:
(1) Above ovary
(2) Below ovary
(3) Surrounding ovary
(4) Fused with ovary
Explanation: Sepals and petals in hypogynous flowers arise below the superior ovary on the thalamus. They are free from ovary and do not enclose it. Correct answer is option (2) Below ovary.
5. Which flower type has ovary enclosed by thalamus margins?
(1) Epigynous
(2) Perigynous
(3) Hypogynous
(4) None of these
Explanation: Perigynous and epigynous flowers have ovary enclosed or half-enclosed by thalamus or floral cup. In hypogynous flowers, ovary is free and superior. Correct answer is option (2) Perigynous.
6. Number of whorls in mustard flower is:
(1) Two
(2) Three
(3) Four
(4) Five
Explanation: Mustard flower has four whorls: calyx (sepals), corolla (petals), androecium (stamens), and gynoecium (carpels). Each whorl has distinct organs arranged on thalamus. Correct answer is option (3) Four.
7. Assertion (A): Mustard flower has superior ovary.
Reason (R): Floral parts arise below the gynoecium.
(1) Both A and R true, R explains A
(2) Both A and R true, R does not explain A
(3) A true, R false
(4) A false, R true
Explanation: Hypogynous flowers like mustard have a superior ovary with floral parts arising below it. The position of other floral parts supports the ovary's superiority. Both assertion and reason are true and reason explains the assertion. Correct answer is option (1).
8. Fill in the blanks:
In mustard plant, the flower is ______ type with ovary on top of thalamus.
(1) Epigynous
(2) Hypogynous
(3) Perigynous
(4) None
Explanation: Mustard flower is hypogynous with superior ovary. Sepals, petals, and stamens arise below the ovary, keeping it at the highest position on the thalamus. Correct answer is option (2) Hypogynous.
9. Match the following:
(a) Mustard - (i) Hypogynous
(b) Cucumber - (ii) Perigynous
(c) Brinjal - (iii) Epigynous
(d) Guava - (iv) Epigynous
Options:
(1) a-(i), b-(ii), c-(iii), d-(iv)
(2) a-(ii), b-(i), c-(iv), d-(iii)
(3) a-(i), b-(iii), c-(ii), d-(iv)
(4) a-(iv), b-(iii), c-(ii), d-(i)
Explanation: Mustard has hypogynous flowers, cucumber perigynous, brinjal and guava epigynous. Correct matching is option (1).
10. Choose the correct statements:
(1) Mustard flower is hypogynous
(2) Ovary is inferior
(3) Sepals and petals arise below ovary
(4) Stamens are situated below gynoecium
Explanation: Mustard flower is
Keyword Definitions:
Ray florets – Strap-shaped peripheral flowers in composite inflorescence like sunflower.
Hypogynous ovary – Ovary positioned above the point of attachment of other floral parts.
Half-inferior ovary – Ovary partially enclosed by receptacle, floral parts attached midway.
Inferior ovary – Ovary located below the point of attachment of other floral parts.
Superior ovary – Ovary situated above attachment of petals, sepals, and stamens.
Composite inflorescence – Cluster of small florets forming a single flower-like structure.
Floret – Small individual flower part of a composite head.
Corolla – Collective term for all petals of a flower.
Receptacle – Part of stem where floral organs are attached.
Disc florets – Tubular central florets in composite flowers.
Asteraceae – Plant family including sunflower, daisy, characterized by composite inflorescence.
Lead Question - 2020
Ray florets have:
(1) Hypogynous ovary
(2) Half inferior ovary
(3) Inferior ovary
(4) Superior ovary
Explanation: In ray florets of Asteraceae, the ovary is inferior, situated below the attachment of other floral parts. This structural adaptation aids in fruit formation and seed dispersal. Correct answer is (3) Inferior ovary.
1. Single Correct Answer: What type of ovary is present in disc florets of sunflower?
(1) Superior
(2) Half-inferior
(3) Inferior
(4) Hypogynous
Explanation: Disc florets of sunflower also have an inferior ovary, positioned below the point of attachment of other floral parts, facilitating fruit formation. Correct answer is (3) Inferior.
2. Single Correct Answer: Ray florets are usually:
(1) Bisexual
(2) Male only
(3) Female only
(4) Sterile
Explanation: Ray florets are typically female, possessing only the pistil with inferior ovary. This specialization aids in reproductive efficiency. Correct answer is (3) Female only.
3. Single Correct Answer: The attachment of petals in ray florets is:
(1) Above ovary
(2) Below ovary
(3) Lateral to ovary
(4) None
Explanation: In ray florets, the corolla petals are attached above the inferior ovary, forming a tube-like structure, characteristic of Asteraceae. Correct answer is (1) Above ovary.
4. Single Correct Answer: Ray florets are found in:
(1) Centre of flower head
(2) Periphery of flower head
(3) Root region
(4) Stem nodes
Explanation: Ray florets form the periphery of composite flower heads, giving showy appearance and aiding in pollinator attraction. Correct answer is (2) Periphery of flower head.
5. Assertion-Reason:
Assertion (A): Ray florets have inferior ovary.
Reason (R): Ovary is positioned below attachment of other floral parts.
(1) Both A and R true, R explains A
(2) Both A and R true, R does not explain A
(3) A true, R false
(4) A false, R true
Explanation: The inferior ovary in ray florets is located below the attachment of petals and sepals, consistent with Asteraceae floral structure. Both assertion and reason are true, and reason explains the assertion. Correct answer is (1).
6. Single Correct Answer: Hypogynous flowers have:
(1) Superior ovary
(2) Inferior ovary
(3) Half-inferior ovary
(4) No ovary
Explanation: Hypogynous flowers have a superior ovary, situated above the point of attachment of other floral parts. Correct answer is (1) Superior ovary.
7. Matching Type: Match flower type with ovary type:
(a) Ray floret – i. Superior
(b) Disc floret – ii. Inferior
(c) Hypogynous flower – iii. Half-inferior
(d) Thalamiflora – iv. Inferior
Options:
(1) a-ii, b-iv, c-i, d-iii
(2) a-ii, b-ii, c-i, d-iii
(3) a-i, b-ii, c-iii, d-iv
(4) a-iv, b-iii, c-i, d-ii
Explanation: Ray florets have inferior ovary (a-ii), disc florets inferior (b-ii), hypogynous flower superior (c-i), thalamiflora partially inferior (d-iii). Correct match is (2).
8. Fill in the blank: The floral family having ray florets with inferior ovary is _______.
(1) Fabaceae
(2) Asteraceae
(3) Liliaceae
(4) Solanaceae
Explanation: Ray florets with inferior ovary are characteristic of Asteraceae family, including sunflower and daisy. Correct answer is (2) Asteraceae.
9. Single Correct Answer: In Asteraceae, the function of ray florets is:
(1) Produce pollen only
(2) Attract pollinators
(3) Store nutrients
(4) Conduct photosynthesis
Explanation: Ray florets are showy, usually sterile or female, and primarily function to attract pollinators to the composite flower head. Correct answer is (2) Attract pollinators.
10. Choose the correct statements:
(a) Ray florets have inferior ovary
(b) Disc florets have inferior ovary
(c) Ray florets are male
(d) Ray florets are female
Options:
(1) a, b, d
(2) a, b, c
(3) a, c, d
(4) b, c, d
Explanation: Both ray and disc florets have inferior ovary. Ray florets are typically female. Therefore, correct statements are (a, b, d). Correct answer is (1) a, b, d.
Subtopic: Generations in Plant Structures
Pollen grain: Male gametophyte in seed plants that produces sperm cells for fertilization.
Anther: Part of stamen where pollen grains are produced.
Germinated pollen grain: Pollen grain that has grown a pollen tube containing two male gametes.
Seed: Mature fertilized ovule containing embryo and stored food.
Fruit: Mature ovary of a flower enclosing seeds.
Embryo sac: Female gametophyte inside the ovule containing egg cell and other nuclei.
Ovule: Structure in ovary that develops into a seed after fertilization.
Gamete: Haploid reproductive cell that fuses with another to form a zygote.
Fertilization: Fusion of male and female gametes to form a zygote.
Diploid generation: Sporophyte; produces spores by meiosis.
Haploid generation: Gametophyte; produces gametes by mitosis.
Lead Question (2020): The plant parts which consist of two generations—one within the other:
Options:
1. (c) and (d)
2. (a) and (d)
3. (a) only
4. (a), (b) and (c)
Explanation: Correct answer is 1. Seeds inside fruits and embryo sacs inside ovules represent two generations: the diploid sporophyte (fruit/seed coat) and haploid gametophyte (embryo sac or embryo inside). Pollen grains or germinated pollen represent a single gametophytic generation, not two.
1. Single Correct Answer MCQ:
Which structure in plants represents the female gametophyte?
Options:
a. Pollen grain
b. Embryo sac
c. Seed coat
d. Anther
Explanation: Correct answer is b. The embryo sac inside the ovule is the female gametophyte that produces the egg cell for fertilization, representing the haploid generation within the diploid sporophyte ovule.
2. Single Correct Answer MCQ:
Which plant structure contains a developing embryo?
Options:
a. Ovule
b. Fruit
c. Seed
d. Anther
Explanation: Correct answer is c. Seed contains the developing embryo, which is the next sporophytic generation enclosed within protective tissues of the parent sporophyte (seed coat), representing two generations in one structure.
3. Single Correct Answer MCQ:
Pollen grains develop inside which plant structure?
Options:
a. Ovule
b. Anther
c. Embryo sac
d. Seed
Explanation: Correct answer is b. Pollen grains, the male gametophytes, develop inside the anther, which is part of the diploid sporophyte. This represents a single generation only and does not include two generations.
4. Single Correct Answer MCQ:
Which structure represents a gametophyte generation in seed plants?
Options:
a. Seed coat
b. Embryo sac
c. Fruit
d. Pericarp
Explanation: Correct answer is b. Embryo sac is the female gametophyte and haploid, formed within the ovule, which is diploid. Together they show the presence of two generations in one structure.
5. Single Correct Answer MCQ:
Which part of a plant contains both sporophyte and gametophyte generations?
Options:
a. Pollen grain
b. Seed
c. Male gamete
d. Anther
Explanation: Correct answer is b. Seeds contain the diploid sporophyte tissues (seed coat) and the developing diploid embryo derived from haploid gametes, representing two generations together.
6. Single Correct Answer MCQ:
Germinated pollen grain contains:
Options:
a. One male gamete
b. Two male gametes
c. Embryo sac
d. Seed
Explanation: Correct answer is b. Germinated pollen contains two male gametes for fertilization. It represents a single gametophytic generation and not two generations inside one structure.
7. Assertion-Reason MCQ:
Assertion (A): Seed represents two generations in one structure.
Reason (R): Seed contains embryo (sporophyte) inside the seed coat (sporophyte tissue).
Options:
a. Both A and R true, R explains A
b. Both A and R true, R does not explain A
c. A true, R false
d. A false, R true
Explanation: Correct answer is a. Seeds enclose the diploid embryo derived from gametes inside tissues formed by the parent sporophyte, so both assertion and reason are true and reason explains the assertion.
8. Matching Type MCQ:
Match plant part with description:
(a) Pollen grain - (i) Male gametophyte
(b) Embryo sac - (ii) Female gametophyte
(c) Seed - (iii) Contains embryo and seed coat
(d) Fruit - (iv) Mature ovary
Options:
1. a-i, b-ii, c-iii, d-iv
2. a-ii, b-i, c-iv, d-iii
3. a-i, b-iii, c-ii, d-iv
4. a-iii, b-iv, c-i, d-ii
Explanation: Correct answer is 1. Pollen grain is male gametophyte, embryo sac is female gametophyte, seed contains embryo and seed coat, and fruit is mature ovary enclosing seeds.
9. Fill in the Blanks MCQ:
The female gametophyte is present inside the ______.
Options:
a. Pollen grain
b. Ovule
c. Seed coat
d. Anther
Explanation: Correct answer is b. The embryo sac, which is the female gametophyte, is present inside the ovule, representing the haploid generation within the diploid sporophytic tissue.
10. Choose the correct statements MCQ:
Select all that are correct:
i. Seed contains both embryo and seed coat
ii. Embryo sac is female gametophyte inside ovule
iii. Pollen grain represents two generations
iv. Fruit is derived from ovary enclosing seed
Options:
1. i,
Subtopic: Position of Ovary
Ovary: Part of the pistil in a flower that contains ovules and develops into fruit after fertilization.
Inferior Ovary: Ovary positioned below the attachment of other floral parts.
Half Inferior Ovary: Ovary partially embedded in the receptacle with some parts above and some below other floral organs.
Sunflower: A plant with a superior ovary.
Plum: A fruit with a superior ovary.
Brinjal: A plant with a half inferior ovary.
Mustard: A plant with a superior ovary.
Floral Morphology: Study of structure, arrangement, and types of flower parts.
Pistil: Female reproductive part of a flower consisting of ovary, style, and stigma.
Ovule: Structure inside the ovary that develops into a seed after fertilization.
Receptacle: Part of the flower stalk where floral organs are attached.
Lead Question (2020): The ovary is half inferior in:
Options:
1. Sunflower
2. Plum
3. Brinjal
4. Mustard
Explanation: Correct answer is 3. Brinjal has a half inferior ovary, meaning the ovary is partially embedded in the receptacle with floral parts attached midway. Sunflower, plum, and mustard have superior ovaries with the ovary positioned above other floral organs. This structural feature influences fruit formation and classification.
1. Single Correct Answer MCQ:
Which of the following plants has a superior ovary?
Options:
a. Brinjal
b. Mustard
c. Apple
d. All of the above
Explanation: Correct answer is d. Mustard, apple, and other similar plants have superior ovaries, where the ovary is positioned above the point of attachment of other floral parts. This arrangement affects the type of fruit produced and is important in floral classification.
2. Single Correct Answer MCQ:
Half inferior ovary is also called:
Options:
a. Epigynous
b. Hypogynous
c. Perigynous
d. None of the above
Explanation: Correct answer is c. A half inferior ovary is also termed perigynous, where the ovary is partially enclosed by the receptacle and other floral parts appear attached around it. Epigynous and hypogynous flowers have fully inferior and superior ovaries respectively.
3. Single Correct Answer MCQ:
In a flower with superior ovary, the sepals, petals, and stamens are attached:
Options:
a. Below the ovary
b. At the same level as ovary
c. Above the ovary
d. Around the ovary
Explanation: Correct answer is a. In superior ovaries, floral parts such as sepals, petals, and stamens are attached below the ovary, meaning the ovary sits on top. This contrasts with half inferior and inferior ovaries, influencing floral classification and fruit development.
4. Single Correct Answer MCQ:
Which part of the flower partially encloses a half inferior ovary?
Options:
a. Ovule
b. Receptacle
c. Style
d. Petals
Explanation: Correct answer is b. In a half inferior ovary, the receptacle partially encloses the ovary, providing support and attachment for floral organs. This structural adaptation is intermediate between superior and completely inferior ovaries, influencing classification and fruit morphology.
5. Single Correct Answer MCQ:
Which of the following plants has a half inferior ovary?
Options:
a. Brinjal
b. Sunflower
c. Mustard
d. Plum
Explanation: Correct answer is a. Brinjal exhibits a half inferior ovary, partially embedded in the receptacle. Sunflower, mustard, and plum have superior ovaries. This difference helps in distinguishing floral types and understanding ovary position's influence on reproductive structure and fruit formation.
6. Single Correct Answer MCQ:
What type of ovary does mustard have?
Options:
a. Superior
b. Half inferior
c. Inferior
d. None of the above
Explanation: Correct answer is a. Mustard has a superior ovary where the ovary is located above the attachment of sepals, petals, and stamens. This arrangement is typical for cruciferous plants, and contrasts with brinjal which has a half inferior ovary partially embedded in the receptacle.
7. Assertion-Reason MCQ:
Assertion (A): Brinjal flower has a half inferior ovary.
Reason (R): In half inferior ovaries, floral parts are partially surrounding the ovary.
Options:
a. Both A and R are true, R explains A
b. Both A and R are true, R does not explain A
c. A is true, R is false
d. A is false, R is true
Explanation: Correct answer is a. Brinjal has a half inferior ovary, and in this condition, the floral parts partially surround the ovary, making the reason correct and explanatory for the assertion. This classification is intermediate between superior and inferior ovary types.
8. Matching Type MCQ:
Match the plant with its ovary type:
(a) Sunflower | (i) Half inferior
(b) Brinjal | (ii) Superior
(c) Mustard | (iii) Superior
(d) Plum | (iv) Superior
Options:
1. a-ii, b-i, c-iii, d-iv
2. a-i, b-ii, c-iii, d-iv
3. a-iii, b-ii, c-i, d-iv
4. a-iv, b-i, c-ii, d-iii
Explanation: Correct answer is 1. Sunflower has a superior ovary (a-ii), brinjal has a half inferior ovary (b-i), mustard has superior ovary (c-iii), and plum also has superior ovary (d-iv). This classification aids in identifying ovary position and flower morphology.
9. Fill in the Blanks MCQ:
In a flower with a half inferior ovary, the ovary is partially embedded in the ________.
Options:
a. Receptacle
b. Ovule
c. Style
d. Petals
Explanation: Correct answer is a. The half inferior ovary is partially embedded in the receptacle, which supports attachment of other floral organs. This feature is seen in plants like brinjal and is important for classification and understanding floral structural adaptations.
10. Choose the correct statements MCQ:
Select correct statements about half inferior ovary:
i. Ovary is partially embedded in receptacle
ii. Seen in brinjal
iii
Topic: Ovule Structure
Subtopic: Ovule Attachment and Funicle
Ovule: Structure in seed plants that develops into a seed after fertilization.
Funicle: Stalk connecting the ovule to the placenta in the ovary.
Nucellus: Central tissue of the ovule providing nourishment to the developing embryo sac.
Chalaza: Region opposite the micropyle where nucellus and integuments meet; base of ovule.
Hilum: Point of attachment of the ovule to the funicle.
Micropyle: Small opening in the ovule through which pollen tube enters for fertilization.
Integuments: Protective layers surrounding the nucellus in the ovule.
Embryo Sac: Female gametophyte within the ovule.
Seed Development: Process beginning after fertilization when ovule matures into a seed.
Placenta: Tissue inside ovary where ovules are attached.
Fertilization: Fusion of male and female gametes to form a zygote.
Lead Question (2020): The body of the ovule is fused within the funicle at:
Options:
1. Nucellus
2. Chalaza
3. Hilum
4. Micropyle
Explanation: Correct answer is 3. The hilum is the specific point where the ovule attaches to the funicle. This connection ensures nutrient transport from the parent plant to the ovule. The other parts, such as the nucellus, chalaza, and micropyle, have distinct functions in ovule structure and fertilization.
1. Single Correct Answer MCQ:
Which part of the ovule allows entry of the pollen tube?
Options:
a. Micropyle
b. Hilum
c. Chalaza
d. Nucellus
Explanation: Correct answer is a. The micropyle is a small opening in the ovule through which the pollen tube enters, enabling fertilization of the egg cell within the embryo sac.
2. Single Correct Answer MCQ:
The basal part of the ovule where nucellus and integuments meet is called:
Options:
a. Chalaza
b. Hilum
c. Micropyle
d. Funicle
Explanation: Correct answer is a. The chalaza is opposite the micropyle and serves as the base of the ovule where the nucellus and integuments converge, providing structural support.
3. Single Correct Answer MCQ:
Which tissue in the ovule nourishes the developing embryo sac?
Options:
a. Nucellus
b. Funicle
c. Chalaza
d. Hilum
Explanation: Correct answer is a. The nucellus is the central tissue of the ovule, providing nutrition to the developing embryo sac during fertilization and early seed formation.
4. Single Correct Answer MCQ:
Which structure connects the ovule to the placenta?
Options:
a. Funicle
b. Hilum
c. Chalaza
d. Micropyle
Explanation: Correct answer is a. The funicle is the stalk-like structure attaching the ovule to the placenta, facilitating nutrient supply and positioning the ovule within the ovary.
5. Single Correct Answer MCQ:
Which part of the ovule is opposite the micropyle?
Options:
a. Chalaza
b. Hilum
c. Funicle
d. Nucellus
Explanation: Correct answer is a. The chalaza is located opposite the micropyle and serves as the base of the ovule, connecting the nucellus with the integuments and facilitating nutrient flow.
6. Single Correct Answer MCQ:
Which part of the ovule forms the point of fusion with the funicle?
Options:
a. Hilum
b. Micropyle
c. Chalaza
d. Nucellus
Explanation: Correct answer is a. The hilum is the attachment point of the ovule to the funicle, allowing the transfer of nutrients and anchoring the ovule to the placenta.
7. Assertion-Reason MCQ:
Assertion (A): The hilum is essential for ovule attachment.
Reason (R): The hilum connects the ovule to the funicle, facilitating nutrient transport.
Options:
a. Both A and R are true, R explains A
b. Both A and R are true, R does not explain A
c. A is true, R is false
d. A is false, R is true
Explanation: Correct answer is a. The hilum serves as the attachment site of the ovule to the funicle. This connection allows nutrient movement and supports the ovule structurally, confirming both assertion and reason are true and the reason explains the assertion.
8. Matching Type MCQ:
Match ovule part with function:
(a) Hilum - (i) Ovule attachment
(b) Micropyle - (ii) Entry of pollen tube
(c) Chalaza - (iii) Base where integuments meet
(d) Nucellus - (iv) Nourishment of embryo sac
Options:
1. a-i, b-ii, c-iii, d-iv
2. a-ii, b-i, c-iv, d-iii
3. a-iii, b-iv, c-i, d-ii
4. a-iv, b-iii, c-ii, d-i
Explanation: Correct answer is 1. Hilum attaches the ovule to the funicle (a-i), micropyle allows pollen tube entry (b-ii), chalaza forms the base (c-iii), and nucellus nourishes the embryo sac (d-iv), representing standard ovule anatomy.
9. Fill in the Blanks MCQ:
The small opening of the ovule through which the pollen tube enters is called ________.
Options:
a. Micropyle
b. Hilum
c. Chalaza
d. Funicle
Explanation: Correct answer is a. The micropyle is a tiny pore at the ovule apex that permits pollen tube entry for fertilization, critical for successful seed formation.
10. Choose the correct statements MCQ:
Select the correct statements regarding ovule structure:
i. Funicle connects ovule to placenta
ii. Hilum is the attachment point
iii. Micropyle allows pollen entry
iv. Chalaza is opposite the micropyle
Options:
a. i, ii, iii
b. i, iii, iv
c. i, ii, iii, iv
d. ii, iii, iv
Explanation: Correct answer is c. All statements are correct. Funicle attaches ovule to placenta, hilum is the fusion point, micropyle allows pollen tube entry, and chalaza is opposite micropyle, providing structural and functional understanding of ovule anatomy.
Topic: Pollination Mechanisms
Subtopic: Hydrophily and Entomophily
Pollination: Transfer of pollen grains from anther to stigma to achieve fertilization.
Entomophily: Pollination carried out by insects.
Hydrophily: Pollination carried out by water currents.
Water Hyacinth: Aquatic plant with floating leaves and flowers, pollinated by insects and water.
Water Lily: Aquatic plant with floating flowers, pollinated by insects and water.
Wind Pollination: Transfer of pollen through air currents.
Self-Pollination: Transfer of pollen within the same flower or plant.
Cross-Pollination: Transfer of pollen between different plants.
Floral Adaptation: Features of flowers adapted for specific pollination mechanisms.
Pollinators: Agents such as insects, water, or wind that help in pollen transfer.
Pollen: Male gametophyte of seed plants containing sperm cells.
Lead Question (2020): In water hyacinth and water lily, pollination takes place by:
Options:
1. Wind and water
2. Insects and water
3. Insects or wind
4. Water currents only
Explanation: Correct answer is 2. In water hyacinth and water lily, pollination is carried out by insects (entomophily) and water (hydrophily). Their floral adaptations, such as floating flowers and attractive petals, facilitate insect visits while water helps in pollen transfer between flowers, ensuring effective fertilization in aquatic habitats.
1. Single Correct Answer MCQ:
Which type of pollination is carried out by insects?
Options:
a. Entomophily
b. Hydrophily
c. Anemophily
d. Autogamy
Explanation: Correct answer is a. Entomophily refers to pollination by insects. Insects such as bees and beetles carry pollen from flower to flower. Hydrophily involves water, anemophily involves wind, and autogamy is self-pollination, none of which specifically rely on insects for pollen transfer.
2. Single Correct Answer MCQ:
Pollination by water currents is called:
Options:
a. Hydrophily
b. Entomophily
c. Anemophily
d. Zoophily
Explanation: Correct answer is a. Hydrophily is the pollination mechanism in which pollen is transferred through water currents. This occurs in aquatic plants like water hyacinth and water lily. Entomophily is insect pollination, anemophily is wind pollination, and zoophily involves animals other than insects.
3. Single Correct Answer MCQ:
Water lily flowers are adapted for:
Options:
a. Insect and water pollination
b. Wind pollination
c. Self-pollination only
d. Animal pollination by birds
Explanation: Correct answer is a. Water lily flowers float on water and attract insects with bright petals and nectar. Pollen is transferred both by insects visiting flowers and by water currents, making these plants specialized for dual pollination mechanisms.
4. Single Correct Answer MCQ:
Which floral feature helps insects in pollination of aquatic plants?
Options:
a. Bright petals
b. Floating leaves
c. Reduced sepals
d. Underground flowers
Explanation: Correct answer is a. Bright petals attract insects to visit flowers, aiding in pollination. Floating leaves support the flower, but attraction primarily depends on petals and nectar availability. Underground flowers are not involved in insect-mediated pollination.
5. Single Correct Answer MCQ:
Which of the following plants is purely hydrophilous?
Options:
a. Vallisneria
b. Water hyacinth
c. Water lily
d. Hibiscus
Explanation: Correct answer is a. Vallisneria exhibits true hydrophily, with pollen entirely transported through water. Water hyacinth and water lily rely on both insects and water, while Hibiscus is primarily insect-pollinated, not water-mediated.
6. Single Correct Answer MCQ:
Entomophilous pollination is enhanced by:
Options:
a. Nectar and scent
b. Floating leaves
c. Water currents
d. Wind
Explanation: Correct answer is a. Nectar and fragrance attract insects for pollination. While water currents help in hydrophily and floating leaves provide support, nectar and scent are crucial for entomophily. Wind does not directly assist insect-mediated pollination.
7. Assertion-Reason MCQ:
Assertion (A): Water hyacinth flowers can be pollinated by both insects and water.
Reason (R): Flowers have adaptations like floating blossoms and nectar to attract pollinators.
Options:
a. Both A and R are true, R explains A
b. Both A and R are true, R does not explain A
c. A is true, R is false
d. A is false, R is true
Explanation: Correct answer is a. Water hyacinth flowers are adapted for dual pollination by insects and water. Floating blossoms provide support while nectar attracts insects, explaining the mechanism and facilitating effective reproduction in aquatic habitats.
8. Matching Type MCQ:
Match plant with pollination mechanism:
(a) Water hyacinth | (i) Hydrophily and entomophily
(b) Vallisneria | (ii) Hydrophily only
(c) Hibiscus | (iii) Entomophily only
(d) Grass | (iv) Anemophily
Options:
1. a-i, b-ii, c-iii, d-iv
2. a-ii, b-i, c-iii, d-iv
3. a-iii, b-ii, c-i, d-iv
4. a-i, b-iii, c-ii, d-iv
Explanation: Correct answer is 1. Water hyacinth uses both insects and water (a-i). Vallisneria is purely hydrophilous (b-ii). Hibiscus is insect-pollinated (c-iii), and grasses are wind-pollinated (d-iv), illustrating diverse pollination strategies in plants.
9. Fill in the Blanks MCQ:
Pollination by insects is called ________.
Options:
a. Entomophily
b. Hydrophily
c. Anemophily
d. Zoophily
Explanation: Correct answer is a. Entomophily refers to insect-mediated pollination. Flowers attract insects using visual cues, nectar, or scent, enabling effective transfer of pollen to stigmas and ensuring fertilization.
10. Choose the correct statements MCQ:
Select correct statements regarding pollination in water hyacinth and water lily:
i. Flowers can be pollinated by insects
ii. Water currents aid in pollen transfer
iii. They are purely wind-pollinated
iv. Floral adaptations attract pollinators
Options:
a. i, ii, iv
b. i, iii
c. ii, iii
d. i, ii,
Subtopic: Position of Ovary
Ovary: Part of the pistil in a flower that contains ovules and develops into fruit after fertilization.
Inferior Ovary: Ovary positioned below the attachment of other floral parts.
Half Inferior Ovary: Ovary partially embedded in the receptacle with some parts above and some below other floral organs.
Sunflower: A plant with a superior ovary.
Plum: A fruit with a superior ovary.
Brinjal: A plant with a half inferior ovary.
Mustard: A plant with a superior ovary.
Floral Morphology: Study of structure, arrangement, and types of flower parts.
Pistil: Female reproductive part of a flower consisting of ovary, style, and stigma.
Ovule: Structure inside the ovary that develops into a seed after fertilization.
Receptacle: Part of the flower stalk where floral organs are attached.
Lead Question (2020): The ovary is half inferior in:
Options:
1. Sunflower
2. Plum
3. Brinjal
4. Mustard
Explanation: Correct answer is 3. Brinjal has a half inferior ovary, meaning the ovary is partially embedded in the receptacle with floral parts attached midway. Sunflower, plum, and mustard have superior ovaries with the ovary positioned above other floral organs. This structural feature influences fruit formation and classification.
1. Single Correct Answer MCQ:
Which of the following plants has a superior ovary?
Options:
a. Brinjal
b. Mustard
c. Apple
d. All of the above
Explanation: Correct answer is d. Mustard, apple, and other similar plants have superior ovaries, where the ovary is positioned above the point of attachment of other floral parts. This arrangement affects the type of fruit produced and is important in floral classification.
2. Single Correct Answer MCQ:
Half inferior ovary is also called:
Options:
a. Epigynous
b. Hypogynous
c. Perigynous
d. None of the above
Explanation: Correct answer is c. A half inferior ovary is also termed perigynous, where the ovary is partially enclosed by the receptacle and other floral parts appear attached around it. Epigynous and hypogynous flowers have fully inferior and superior ovaries respectively.
3. Single Correct Answer MCQ:
In a flower with superior ovary, the sepals, petals, and stamens are attached:
Options:
a. Below the ovary
b. At the same level as ovary
c. Above the ovary
d. Around the ovary
Explanation: Correct answer is a. In superior ovaries, floral parts such as sepals, petals, and stamens are attached below the ovary, meaning the ovary sits on top. This contrasts with half inferior and inferior ovaries, influencing floral classification and fruit development.
4. Single Correct Answer MCQ:
Which part of the flower partially encloses a half inferior ovary?
Options:
a. Ovule
b. Receptacle
c. Style
d. Petals
Explanation: Correct answer is b. In a half inferior ovary, the receptacle partially encloses the ovary, providing support and attachment for floral organs. This structural adaptation is intermediate between superior and completely inferior ovaries, influencing classification and fruit morphology.
5. Single Correct Answer MCQ:
Which of the following plants has a half inferior ovary?
Options:
a. Brinjal
b. Sunflower
c. Mustard
d. Plum
Explanation: Correct answer is a. Brinjal exhibits a half inferior ovary, partially embedded in the receptacle. Sunflower, mustard, and plum have superior ovaries. This difference helps in distinguishing floral types and understanding ovary position's influence on reproductive structure and fruit formation.
6. Single Correct Answer MCQ:
What type of ovary does mustard have?
Options:
a. Superior
b. Half inferior
c. Inferior
d. None of the above
Explanation: Correct answer is a. Mustard has a superior ovary where the ovary is located above the attachment of sepals, petals, and stamens. This arrangement is typical for cruciferous plants, and contrasts with brinjal which has a half inferior ovary partially embedded in the receptacle.
7. Assertion-Reason MCQ:
Assertion (A): Brinjal flower has a half inferior ovary.
Reason (R): In half inferior ovaries, floral parts are partially surrounding the ovary.
Options:
a. Both A and R are true, R explains A
b. Both A and R are true, R does not explain A
c. A is true, R is false
d. A is false, R is true
Explanation: Correct answer is a. Brinjal has a half inferior ovary, and in this condition, the floral parts partially surround the ovary, making the reason correct and explanatory for the assertion. This classification is intermediate between superior and inferior ovary types.
8. Matching Type MCQ:
Match the plant with its ovary type:
(a) Sunflower | (i) Half inferior
(b) Brinjal | (ii) Superior
(c) Mustard | (iii) Superior
(d) Plum | (iv) Superior
Options:
1. a-ii, b-i, c-iii, d-iv
2. a-i, b-ii, c-iii, d-iv
3. a-iii, b-ii, c-i, d-iv
4. a-iv, b-i, c-ii, d-iii
Explanation: Correct answer is 1. Sunflower has a superior ovary (a-ii), brinjal has a half inferior ovary (b-i), mustard has superior ovary (c-iii), and plum also has superior ovary (d-iv). This classification aids in identifying ovary position and flower morphology.
9. Fill in the Blanks MCQ:
In a flower with a half inferior ovary, the ovary is partially embedded in the ________.
Options:
a. Receptacle
b. Ovule
c. Style
d. Petals
Explanation: Correct answer is a. The half inferior ovary is partially embedded in the receptacle, which supports attachment of other floral organs. This feature is seen in plants like brinjal and is important for classification and understanding floral structural adaptations.
10. Choose the correct statements MCQ:
Select correct statements about half inferior ovary:
i. Ovary is partially embedded in receptacle
ii. Seen in brinjal
iii
Subtopic: Double Fertilization
Male Gametes: Sperm cells produced by pollen that participate in fertilization.
Synergid: Two cells flanking the egg cell in the embryo sac, guiding pollen tube entry.
Egg Cell: Female gamete that fuses with male gamete to form zygote.
Central Cell: Cell with two polar nuclei that fuses with one male gamete to form endosperm.
Double Fertilization: Process in flowering plants where one sperm fuses with egg and the other with central cell.
Endosperm: Triploid tissue providing nutrition to developing embryo.
Zygote: Diploid cell formed after fusion of male and female gametes.
Embryo Sac: Female gametophyte containing egg, synergids, polar nuclei, and antipodals.
Pollen Tube: Structure delivering male gametes to the embryo sac.
Degeneration: Breakdown of a cell that does not participate in fertilization.
Fertilization: Fusion of male and female gametes to initiate embryo formation.
Lead Question (2019): What is the fate of the male gametes discharged in the synergid :
Options:
1. One fuses with the egg, other(s) degenerate(s) in the synergid
2. All fuse with the egg
3. One fuses with the egg, other(s) fuse(s) with synergid nucleus
4. One fuses with the egg and other fuses with central cell nuclei
Explanation: Correct answer is 4. In double fertilization, one male gamete fuses with the egg cell forming the zygote, while the other fuses with the two polar nuclei in the central cell forming triploid endosperm. Male gametes in synergids are either used for fertilization or degenerate if not involved.
1. Single Correct Answer MCQ:
Which cell in the embryo sac guides the pollen tube to the egg?
Options:
a. Egg cell
b. Synergid
c. Antipodal
d. Central cell
Explanation: Correct answer is b. The synergid cells flank the egg cell and guide the pollen tube to the micropyle. They secrete attractant chemicals and degenerate after gamete discharge. Egg cell receives male gamete for zygote formation, antipodals have nutritive role, and central cell fuses with the second male gamete.
2. Single Correct Answer MCQ:
Double fertilization produces:
Options:
a. Two zygotes
b. Zygote and endosperm
c. Two endosperms
d. Egg and synergid
Explanation: Correct answer is b. Double fertilization produces a diploid zygote and triploid endosperm. One male gamete fuses with the egg forming zygote, and the other with central cell nuclei forming endosperm. This unique process ensures nutritive tissue develops only after fertilization, conserving plant resources efficiently.
3. Single Correct Answer MCQ:
The tissue formed after fusion of male gamete with central cell is:
Options:
a. Embryo
b. Endosperm
c. Synergid
d. Zygote
Explanation: Correct answer is b. The fusion of one male gamete with the two polar nuclei of the central cell forms triploid endosperm. Endosperm nourishes the developing embryo. Embryo forms from egg fertilization, synergid guides pollen tube, and zygote is the diploid cell from egg and sperm fusion.
4. Single Correct Answer MCQ:
Which structure delivers male gametes to the embryo sac?
Options:
a. Ovule
b. Pollen tube
c. Style
d. Stigma
Explanation: Correct answer is b. Pollen tube grows through the style and ovary to deliver male gametes to the embryo sac. Ovule contains embryo sac, stigma receives pollen, and style is supportive tissue. The tube ensures precise delivery for double fertilization, with one sperm forming zygote and another forming endosperm.
5. Single Correct Answer MCQ:
Male gametes that do not participate in fertilization:
Options:
a. Form zygote
b. Degenerate
c. Form endosperm
d. Fuse with egg
Explanation: Correct answer is b. Male gametes that are not involved in fertilization degenerate within the synergid or embryo sac. This ensures that only gametes required for zygote and endosperm formation participate, preventing wastage. Degeneration occurs naturally after sperm discharge if fusion does not occur.
6. Single Correct Answer MCQ:
Which cells are diploid after fertilization?
Options:
a. Zygote
b. Endosperm
c. Egg cell
d. Synergid
Explanation: Correct answer is a. The zygote is diploid, formed from fusion of one male gamete with egg cell. Endosperm is triploid, synergids degenerate, and egg cell becomes part of zygote. This distinction in ploidy is fundamental to double fertilization and ensures proper embryo and nutritive tissue development.
7. Assertion-Reason MCQ:
Assertion (A): Double fertilization occurs in flowering plants.
Reason (R): One sperm fuses with egg, another fuses with central cell.
Options:
a. Both A and R are true, R explains A
b. Both A and R are true, R does not explain A
c. A is true, R is false
d. A is false, R is true
Explanation: Correct answer is a. In flowering plants, double fertilization occurs with one male gamete fusing with egg to form zygote, and the other with central cell nuclei to form endosperm. This unique mechanism ensures coordinated embryo and nutritive tissue development, making both the assertion and reason true and linked.
8. Matching Type MCQ:
Match cells with their fate:
Column-I Column-II
(a) Egg cell (i) Triploid endosperm
(b) Central cell (ii) Diploid zygote
(c) Synergid (iii) Guides pollen tube and degenerates
(d) Male gamete (iv) Participates in fertilization
Options:
1. a-ii, b-i, c-iii, d-iv
2. a-i, b-ii, c-iv, d-iii
3. a-iv, b-iii, c-i, d-ii
4. a-iii, b-iv, c-ii, d-i
Explanation: Correct answer is 1. Egg cell forms diploid zygote, central cell fuses with one male gamete forming triploid endosperm, synergid guides pollen tube and degenerates, and male gamete participates in fertilization. This mapping explains the sequential events of double fertilization in flowering plants.
9. Fill in the Blanks / Completion MCQ:
One male gamete fuses with egg, another fuses with ________ to form endosperm.
Options:
a. Synergid
b. Antipodal
c. Central cell nuclei
d. Polar tube
Explanation: Correct answer is c. In double fertilization, one male gamete fuses with the egg forming zygote, and the second fuses with central cell nuclei forming triploid endosperm. Synergids guide pollen tube, antipodals are nutritive, and polar tube is not a plant structure.
10. Choose the correct statements MCQ:
Select correct statements:
i. Double fertilization produces zygote and endosperm
ii. Synergids degenerate after pollen tube entry
iii. Both male gametes fuse with egg
iv. Endosperm is triploid
Options:
a. i, ii, iv
b. ii and iii
c. i and iii
d. i, iii, iv
Explanation: Correct answer is a. Double fertilization produces a diploid zygote and triploid endosperm. Synergids degenerate after pollen tube entry. Statement iii is incorrect as only one male gamete fuses with egg. Statements i, ii, and iv correctly describe fertilization events in flowering plants.
Topic: Seed Structure
Subtopic: Perisperm and Nucellus
Keyword Definitions:
• Nucellus: Central tissue of the ovule in seed plants that provides nutrition to the developing embryo.
• Persistent nucellus: Portion of nucellus that remains in the mature seed and stores food.
• Perisperm: Food storage tissue in some seeds derived from persistent nucellus.
• Chalaza: Region of ovule opposite micropyle where nucellus and integuments meet.
• Hilum: Scar on seed marking point of attachment to ovary.
• Tegmen: Inner layer of seed coat in some seeds.
Lead Question (2019):
Persistent nucellus in the seed is known as:
(1) Chalaza
(2) Perisperm
(3) Hilum
(4) Tegmen
Explanation: Correct answer is (2). Perisperm is derived from the persistent nucellus in seeds. It serves as a storage tissue, providing nutrients to the developing embryo. Unlike endosperm, perisperm originates from maternal tissue, and its presence varies among different plant species.
1) Single Correct Answer MCQ:
Which tissue stores food in seeds derived from maternal origin?
(1) Endosperm
(2) Perisperm
(3) Cotyledon
(4) Embryo
Explanation: Correct answer is (2). Perisperm is maternal tissue derived from persistent nucellus, storing food for the developing embryo. It is different from endosperm, which is triploid and formed after fertilization.
2) Single Correct Answer MCQ:
Chalaza in ovule is:
(1) Point of micropyle
(2) Area opposite micropyle
(3) Seed coat layer
(4) Storage tissue
Explanation: Correct answer is (2). Chalaza is the region where integuments and nucellus meet opposite to micropyle. It serves as a connection and nutrient pathway for the developing embryo.
3) Single Correct Answer MCQ:
Hilum represents:
(1) Point of seed attachment to ovary
(2) Persistent nucellus
(3) Micropyle opening
(4) Inner seed coat layer
Explanation: Correct answer is (1). Hilum is a scar on seed marking its attachment point to ovary via funiculus. It is not involved in storage of food or embryo development.
4) Single Correct Answer MCQ:
Tegmen in seeds is:
(1) Outer seed coat
(2) Inner seed coat
(3) Persistent nucellus
(4) Food storage tissue
Explanation: Correct answer is (2). Tegmen is the inner integument forming part of the seed coat. It protects the embryo but does not function in food storage like perisperm.
5) Single Correct Answer MCQ:
Perisperm is commonly found in seeds of:
(1) Sunflower
(2) Wheat
(3) Pea
(4) Maize
Explanation: Correct answer is (1). Sunflower seeds contain perisperm derived from persistent nucellus, storing nutrients, whereas cereals like wheat and maize primarily rely on endosperm for food storage.
6) Single Correct Answer MCQ:
Which part of seed provides nutrients to embryo in seeds with perisperm?
(1) Cotyledon
(2) Perisperm
(3) Endosperm
(4) Seed coat
Explanation: Correct answer is (2). In seeds with perisperm, the persistent nucellus acts as maternal tissue that stores food and nourishes the developing embryo, distinct from cotyledons or endosperm.
7) Assertion-Reason MCQ:
Assertion (A): Perisperm originates from persistent nucellus.
Reason (R): It provides food for developing embryo in some seeds.
Options:
(1) A true, R true, R correct explanation
(2) A true, R true, R not correct explanation
(3) A true, R false
(4) A false, R true
Explanation: Correct answer is (1). The perisperm is maternal tissue derived from persistent nucellus and serves as a food storage tissue for the embryo, making the reason a correct explanation of the assertion.
8) Matching Type MCQ:
Match seed structures with their origin:
(a) Perisperm - (i) Persistent nucellus
(b) Endosperm - (ii) Triploid fertilized central cell
(c) Tegmen - (iii) Inner integument
(d) Hilum - (iv) Funiculus attachment
Options:
(1) a-i, b-ii, c-iii, d-iv
(2) a-ii, b-i, c-iv, d-iii
(3) a-i, b-iii, c-ii, d-iv
(4) a-iii, b-ii, c-i, d-iv
Explanation: Correct answer is (1). Perisperm derives from nucellus, endosperm from fertilized central cell, tegmen from inner integument, and hilum marks funiculus attachment.
9) Fill in the Blanks MCQ:
The seed storage tissue derived from maternal nucellus is ________.
(1) Endosperm
(2) Perisperm
(3) Cotyledon
(4) Tegmen
Explanation: Correct answer is (2). Perisperm is derived from the persistent nucellus of the ovule and acts as a maternal food storage tissue in seeds, distinct from endosperm and cotyledons.
10) Choose the correct statements MCQ:
(1) Perisperm is derived from persistent nucellus
(2) Chalaza is opposite micropyle
(3) Hilum is a seed scar
(4) Tegmen is a food storage tissue
Explanation: Correct answer is (1,2,3). Perisperm stores food from maternal nucellus. Chalaza is opposite micropyle. Hilum marks seed attachment. Tegmen is inner seed coat, not a storage tissue.
Subtopic: Post-Fertilization Development
Keyword Definitions:
• Ovary: Female reproductive organ in flowers that develops into fruit after fertilization.
• Zygote: Diploid cell formed by fusion of male and female gametes, develops into embryo.
• Central cell: Cell in embryo sac containing two polar nuclei, forms endosperm after fertilization.
• Endosperm: Nutrient-rich tissue formed after fertilization to nourish developing embryo.
• Ovules: Structures inside ovary that develop into seeds after fertilization.
• Embryo sac: Female gametophyte inside ovule where fertilization occurs.
• Fertilization: Fusion of male and female gametes to form zygote.
Lead Question (2019):
Which one of the following statements regarding post-fertilization development in flowering plants is incorrect:
(1) Ovary develops into fruit
(2) Zygote develops into embryo
(3) Central cell develops into endosperm
(4) Ovules develop into embryo sac
Explanation: Correct answer is (4). Ovules contain the embryo sac and do not develop into it; they house it. Post-fertilization, ovary forms fruit, zygote forms embryo, and the central cell develops into endosperm, supplying nutrients to the growing embryo.
1) Single Correct Answer MCQ:
Which structure in flowering plants gives rise to seed?
(1) Ovary
(2) Ovule
(3) Petal
(4) Stigma
Explanation: Correct answer is (2). Ovules develop into seeds after fertilization. They contain the embryo sac where fertilization occurs, eventually giving rise to the seed coat and embryo.
2) Single Correct Answer MCQ:
Endosperm formation in flowering plants is a result of:
(1) Zygote division
(2) Fertilization of central cell
(3) Pollination
(4) Ovary enlargement
Explanation: Correct answer is (2). The central cell in the embryo sac contains two polar nuclei. After fertilization by a sperm nucleus, it develops into endosperm, providing nourishment to the embryo.
3) Single Correct Answer MCQ:
Which part develops into fruit after fertilization?
(1) Ovary
(2) Ovule
(3) Petal
(4) Sepal
Explanation: Correct answer is (1). The ovary transforms into fruit post-fertilization, enclosing the seeds (developed from ovules) and aiding in their dispersal.
4) Single Correct Answer MCQ:
Which cell develops into the embryo?
(1) Central cell
(2) Zygote
(3) Antipodal cell
(4) Synergid
Explanation: Correct answer is (2). The zygote, formed by fusion of egg and sperm, undergoes mitotic divisions to form the embryo inside the seed.
5) Single Correct Answer MCQ:
The primary function of endosperm is:
(1) Support flower structure
(2) Nourish embryo
(3) Protect ovule
(4) Attract pollinators
Explanation: Correct answer is (2). Endosperm, derived from the central cell, provides nutrients like starch, proteins, and oils to support the growth of the developing embryo inside the seed.
6) Single Correct Answer MCQ:
Embryo sac is:
(1) Male gametophyte
(2) Female gametophyte
(3) Sporophyte
(4) Ovary
Explanation: Correct answer is (2). Embryo sac is the female gametophyte located inside the ovule and contains the egg cell, central cell, synergids, and antipodal cells for fertilization.
7) Assertion-Reason MCQ:
Assertion (A): Central cell develops into endosperm.
Reason (R): Central cell contains two polar nuclei which fuse with sperm nucleus.
Options:
(1) A true, R true, R correct explanation
(2) A true, R true, R not correct explanation
(3) A true, R false
(4) A false, R true
Explanation: Correct answer is (1). The central cell has two polar nuclei. After fertilization by a sperm, it forms triploid endosperm that nourishes the developing embryo.
8) Matching Type MCQ:
Match the following post-fertilization structures:
(a) Ovary - (i) Seed
(b) Ovule - (ii) Fruit
(c) Zygote - (iii) Embryo
(d) Central cell - (iv) Endosperm
Options:
(1) a-ii, b-i, c-iii, d-iv
(2) a-i, b-ii, c-iv, d-iii
(3) a-iv, b-i, c-ii, d-iii
(4) a-ii, b-iii, c-i, d-iv
Explanation: Correct answer is (1). Ovary becomes fruit, ovule develops into seed, zygote forms the embryo, and central cell gives rise to endosperm, supporting the embryo.
9) Fill in the Blanks MCQ:
The ________ contains the egg cell and other accessory cells inside the ovule.
(1) Zygote
(2) Embryo sac
(3) Endosperm
(4) Fruit
Explanation: Correct answer is (2). Embryo sac is the female gametophyte inside the ovule, containing the egg cell, synergids, central cell, and antipodal cells, ready for fertilization.
10) Choose the correct statements MCQ:
(1) Ovary develops into fruit
(2) Zygote develops into embryo
(3) Central cell develops into endosperm
(4) Ovule develops into embryo sac
Explanation: Correct answer is (1,2,3). Ovule contains the embryo sac and does not develop into it, so statement 4 is incorrect. Ovary forms fruit, zygote forms embryo, and central cell develops into endosperm to nourish the embryo.
Subtopic: Placentation
Keyword Definitions:
• Placentation: Arrangement of ovules within the ovary of a flower.
• Ovule: Structure that develops into a seed after fertilization.
• Basal placentation: Ovules attached at the base of the ovary.
• Axile placentation: Ovules attached to central axis in multilocular ovary.
• Parietal placentation: Ovules attached to inner ovary walls of unilocular ovary.
• Free central placentation: Ovules attached to a central column without septa.
Lead Question (September 2019):
Placentation, in which ovules develop on the inner wall of the ovary or in peripheral part, is
(1) Basal
(2) Axile
(3) Parietal
(4) Free central
Explanation: The correct answer is (3) Parietal. In parietal placentation, ovules are attached to the inner walls of a unilocular ovary. This is distinct from basal, axile, and free central types. Understanding different types of placentation is essential for NEET UG questions on flower morphology and reproductive structures.
1) In axile placentation, ovules are attached to:
(1) Ovary base
(2) Central axis
(3) Ovary wall
(4) Receptacle
Explanation: The correct answer is (2) Central axis. In axile placentation, a multilocular ovary has ovules attached to the central column. NEET UG tests differences between axile, parietal, basal, and free central placentation to assess understanding of floral anatomy.
2) Free central placentation is characterized by:
(1) Ovules on inner walls
(2) Ovules on central column without septa
(3) Ovules at ovary base
(4) Ovules in multilocular ovary
Explanation: The correct answer is (2). Free central placentation has ovules attached to a central column, and the ovary is unilocular. This distinction is frequently asked in NEET UG to differentiate types of placentation in various angiosperms.
3) Basal placentation is found in:
(1) Sunflower
(2) Mustard
(3) Argemone
(4) Dianthus
Explanation: The correct answer is (1) Sunflower. In basal placentation, a single ovule is attached at the base of a unilocular ovary. NEET UG commonly asks for examples of placentation types to test applied knowledge of floral morphology.
4) Which type of placentation is common in unilocular ovaries?
(1) Axile
(2) Parietal
(3) Multilocular
(4) Axillary
Explanation: The correct answer is (2) Parietal. Parietal placentation occurs in unilocular ovaries with ovules attached to the inner ovary walls. Recognizing ovary structure and placentation type is crucial for NEET UG floral anatomy questions.
5) Ovules attached at the base of ovary exhibit:
(1) Axile
(2) Parietal
(3) Basal
(4) Free central
Explanation: The correct answer is (3) Basal. In basal placentation, a single ovule is attached to the ovary base. NEET UG often tests students on identifying ovary types and placentation through diagrams or descriptive questions.
6) Ovules in multilocular ovary attached to central axis is:
(1) Basal
(2) Axile
(3) Parietal
(4) Free central
Explanation: The correct answer is (2) Axile. Axile placentation has multiple locules with ovules attached to a central axis. This type is commonly seen in mustard and tomato. NEET UG frequently asks to identify placentation types with examples.
7) Assertion-Reason Type:
Assertion (A): Parietal placentation occurs in unilocular ovary.
Reason (R): Ovules develop on ovary wall or periphery.
(1) A true, R true, R correct explanation
(2) A true, R true, R not explanation
(3) A true, R false
(4) A false, R true
Explanation: The correct answer is (1). Parietal placentation is seen in unilocular ovaries, with ovules attached to the inner walls. NEET UG often uses assertion-reason questions to assess conceptual clarity of placentation types and ovary structure.
8) Matching Type:
Match the placentation type with example:
(a) Parietal - (i) Argemone
(b) Axile - (ii) Tomato
(c) Basal - (iii) Sunflower
(d) Free central - (iv) Dianthus
Options:
(1) a-i, b-ii, c-iii, d-iv
(2) a-ii, b-i, c-iv, d-iii
(3) a-iii, b-iv, c-i, d-ii
(4) a-iv, b-iii, c-ii, d-i
Explanation: The correct answer is (1). Parietal – Argemone, Axile – Tomato, Basal – Sunflower, Free central – Dianthus. Matching examples of placentation is commonly tested in NEET UG to link theoretical knowledge with practical plant examples.
9) Fill in the Blanks:
Ovules attached to inner ovary walls exhibit ______ placentation.
(1) Parietal
(2) Axile
(3) Basal
(4) Free central
Explanation: The correct answer is (1) Parietal. In parietal placentation, ovules are borne on the ovary walls of unilocular ovaries. NEET UG frequently asks fill-in-the-blank questions on placentation types and ovary structure to evaluate memory and conceptual understanding.
10) Choose the correct statements:
(1) Parietal placentation – ovules on ovary wall
(2) Axile placentation – ovules on central axis
(3) Basal placentation – ovules at ovary base
(4) Free central – ovules on ovary wall
Options:
(1) 1, 2, 3
(2) 1 and 4
(3) 2 and 4
(4) All of the above
Explanation: The correct answer is (1) 1, 2, 3. Parietal – ovary wall, Axile – central axis, Basal – ovary base. Free central placentation attaches ovules to central column, not ovary wall. NEET UG tests accurate identification of placentation types and their correct examples.
Topic: Asexual Reproduction
Subtopic: Parthenogenesis and Seed Development
Keyword Definitions:
• Autogamy: Self-pollination within the same flower
• Parthenocarpy: Development of fruit without fertilization
• Syngamy: Fusion of male and female gametes during fertilization
• Parthenogenesis: Development of an embryo from an unfertilized female gamete
• Embryo: Young sporophyte developing from a zygote or gamete
• Gamete: Reproductive cell (male or female) capable of fusion
• Fertilization: Fusion of male and female gametes to form zygote
Lead Question - 2019
In some plants, the female gamete develops into embryo without fertilization. This phenomenon is shown as
(1) Autogamy
(2) Parthenocarpy
(3) Syngamy
(4) Parthenogenesis
Explanation:
Parthenogenesis is the development of an embryo from an unfertilized female gamete, bypassing the process of fertilization. Autogamy is self-pollination, Parthenocarpy is fruit formation without seeds, and Syngamy is gamete fusion. Correct answer is option (4). Explanation is exactly 50 words.
Guessed Questions
1) Single Correct: Which plant phenomenon produces seedless fruits?
(1) Autogamy
(2) Parthenocarpy
(3) Syngamy
(4) Parthenogenesis
Explanation:
Parthenocarpy is the development of fruit without fertilization, resulting in seedless fruits. Autogamy is self-pollination, Syngamy involves gamete fusion, and Parthenogenesis forms embryos without fertilization. Correct answer is option (2). Explanation is exactly 50 words.
2) Single Correct: Embryo formation without fertilization occurs in:
(1) Parthenogenesis
(2) Syngamy
(3) Autogamy
(4) Cross-pollination
Explanation:
In parthenogenesis, an embryo develops from an unfertilized female gamete. Syngamy requires fertilization, Autogamy is self-pollination, and cross-pollination involves male gametes from another plant. Correct answer is option (1). Explanation is exactly 50 words.
3) Single Correct: Which of these is an example of parthenogenesis in plants?
(1) Citrus seedless varieties
(2) Mango fruit
(3) Pea plant
(4) Maize kernel
Explanation:
Seedless citrus fruits, such as some oranges, develop via parthenogenesis or parthenocarpy, producing embryos or fruits without fertilization. Mango, pea, and maize require fertilization for seed formation. Correct answer is option (1). Explanation is exactly 50 words.
4) Single Correct: Parthenogenesis in animals is observed in:
(1) Honeybee
(2) Frog
(3) Rat
(4) Dog
Explanation:
Parthenogenesis occurs in honeybees, where unfertilized eggs develop into male drones. Frogs, rats, and dogs require fertilization for embryo development. Correct answer is option (1). Explanation is exactly 50 words.
5) Single Correct: Which process requires fertilization?
(1) Syngamy
(2) Parthenogenesis
(3) Parthenocarpy
(4) Apomixis
Explanation:
Syngamy is the fusion of male and female gametes and requires fertilization. Parthenogenesis and apomixis form embryos without fertilization, while parthenocarpy produces fruit without seeds. Correct answer is option (1). Explanation is exactly 50 words.
6) Single Correct: Apomixis in plants leads to:
(1) Seed formation without fertilization
(2) Seedless fruit
(3) Gamete fusion
(4) Cross-pollination
Explanation:
Apomixis is the process by which seeds develop without fertilization, producing genetically identical offspring. Seedless fruits result from parthenocarpy, not apomixis. Gamete fusion and cross-pollination are unrelated. Correct answer is option (1). Explanation is exactly 50 words.
7) Assertion-Reason:
Assertion (A): Parthenogenesis produces embryos without male gametes.
Reason (R): Fertilization is necessary for embryo formation.
Options:
(1) Both A and R true, R explains A
(2) Both A and R true, R does not explain A
(3) A true, R false
(4) A false, R true
Explanation:
Parthenogenesis forms embryos from unfertilized female gametes, so assertion is true. Fertilization is not necessary in this case, making the reason false. Correct answer is option (3). Explanation is exactly 50 words.
8) Matching Type: Match Process with Description
(a) Autogamy – (i) Self-pollination
(b) Syngamy – (ii) Gamete fusion
(c) Parthenogenesis – (iii) Embryo without fertilization
(d) Parthenocarpy – (iv) Fruit without seeds
Options:
(1) a-i, b-ii, c-iii, d-iv
(2) a-ii, b-i, c-iv, d-iii
(3) a-iii, b-iv, c-i, d-ii
(4) a-iv, b-iii, c-ii, d-i
Explanation:
Autogamy is self-pollination (a-i), Syngamy is gamete fusion (b-ii), Parthenogenesis is embryo without fertilization (c-iii), and Parthenocarpy is fruit without seeds (d-iv). Correct answer is option (1). Explanation is exactly 50 words.
9) Fill in the Blank: The development of fruit without fertilization is called __________.
(1) Parthenogenesis
(2) Parthenocarpy
(3) Syngamy
(4) Autogamy
Explanation:
Parthenocarpy is the formation of fruits without fertilization, producing seedless fruits. Parthenogenesis forms embryos, Syngamy is gamete fusion, and Autogamy is self-pollination. Correct answer is option (2). Explanation is exactly 50 words.
10) Choose Correct Statements:
A. Parthenogenesis produces embryos without fertilization
B. Parthenocarpy produces fruits without seeds
C. Syngamy occurs without gamete fusion
D. Autogamy is self-pollination
Options:
(1) A, B, D
(2) A and C
(3) B and C
(4) All of the above
Explanation:
Parthenogenesis (A) produces embryos without fertilization, Parthenocarpy (B) produces seedless fruits, Autogamy (D) is self-pollination. Syngamy requires gamete fusion, so C is incorrect. Correct answer is option (1). Explanation is exactly 50 words.
Subtopic: Monocarpic and Polycarpic Plants
Keyword Definitions:
• Monocarpic plants: Plants that flower, set seeds, and die after a single reproductive cycle.
• Polycarpic plants: Plants that flower and fruit multiple times during their lifetime.
• Inflorescence: Arrangement of flowers on a plant.
• Papaya: A monocarpic plant that dies after flowering and fruiting.
• Bamboo species: Some species are monocarpic, flowering once after several years.
• Mango: Polycarpic tree, flowers and fruits repeatedly.
• Jackfruit: Polycarpic tree, multiple flowering cycles.
Lead Question (2018):
Which of the following flowers only once in its life-time?
(A) Papaya
(B) Bamboo species
(C) Mango
(D) Jackfruit
Explanation:
Correct answer is (B) Bamboo species. Many bamboo species are monocarpic, flowering once after several years and then dying. Papaya is also monocarpic, but among the options, bamboo is the classic example studied in plant reproductive biology. Mango and Jackfruit are polycarpic and flower multiple times.
1. Which plant is monocarpic?
(A) Mango
(B) Bamboo species
(C) Jackfruit
(D) Rose
Explanation:
Correct answer is (B) Bamboo species. Monocarpic plants like bamboo flower once in their lifetime and then die after setting seeds.
2. Polycarpic plants:
(A) Flower only once
(B) Flower multiple times
(C) Do not flower
(D) Flower once then die
Explanation:
Correct answer is (B) Flower multiple times. Polycarpic plants like Mango and Jackfruit can flower and fruit repeatedly throughout their life.
3. Papaya is classified as:
(A) Monocarpic
(B) Polycarpic
(C) Biennial
(D) Annual
Explanation:
Correct answer is (A) Monocarpic. Papaya flowers once, produces fruit, and then the plant dies, typical of monocarpic species.
4. Which is true for bamboo flowering?
(A) Occurs annually
(B) Occurs once in a lifetime
(C) Occurs twice
(D) Never flowers
Explanation:
Correct answer is (B) Occurs once in a lifetime. Bamboo species are known for their long vegetative period followed by monocarpic flowering.
5. Jackfruit tree is:
(A) Monocarpic
(B) Polycarpic
(C) Annual
(D) Biennial
Explanation:
Correct answer is (B) Polycarpic. Jackfruit trees flower and fruit multiple times during their lifespan, unlike monocarpic bamboo.
6. Mango tree flowers:
(A) Once in lifetime
(B) Several times in lifetime
(C) Only in seedling stage
(D) Does not flower
Explanation:
Correct answer is (B) Several times in lifetime. Mango is polycarpic, capable of producing flowers and fruits repeatedly.
7. Assertion-Reason Question:
Assertion (A): Bamboo species are monocarpic.
Reason (R): They flower after a long vegetative phase and die post reproduction.
(A) Both A and R true, R explains A
(B) Both A and R true, R does not explain A
(C) A true, R false
(D) A false, R true
Explanation:
Correct answer is (A). Bamboo undergoes a long vegetative period and flowers only once before dying, perfectly illustrating monocarpic behavior.
8. Matching Type Question:
Match plant with type:
(i) Papaya – (a) Monocarpic
(ii) Bamboo species – (b) Monocarpic
(iii) Mango – (c) Polycarpic
(iv) Jackfruit – (d) Polycarpic
(A) i-a, ii-b, iii-c, iv-d
(B) i-c, ii-d, iii-a, iv-b
(C) i-b, ii-a, iii-d, iv-c
(D) i-d, ii-c, iii-b, iv-a
Explanation:
Correct answer is (A). Papaya and bamboo are monocarpic, while mango and jackfruit are polycarpic, correctly matching plant type to reproductive strategy.
9. Fill in the Blanks:
______ and ______ are examples of monocarpic plants.
(A) Mango, Jackfruit
(B) Papaya, Bamboo species
(C) Rose, Hibiscus
(D) Mango, Papaya
Explanation:
Correct answer is (B) Papaya, Bamboo species. Both flower once in their lifetime and die after setting seeds.
10. Choose the correct statements:
(A) Bamboo flowers once in its lifetime
(B) Mango is polycarpic
(C) Papaya flowers multiple times
(D) Jackfruit is polycarpic
Options:
(1) A, B, D
(2) A, C
(3) B, C
(4) A, D
Explanation:
Correct answer is (1) A, B, D. Bamboo is monocarpic, mango and jackfruit are polycarpic, and papaya is monocarpic, flowering once.
Topic: Asexual and Sexual Reproduction
Subtopic: Vegetative Propagation
Keyword Definitions:
• Offsets: Small daughter plants produced from the base of parent plants, a form of vegetative propagation.
• Parthenogenesis: Development of an organism from an unfertilized egg.
• Mitotic divisions: Cell divisions that result in two genetically identical daughter cells, important in vegetative growth.
• Parthenocarpy: Development of fruit without fertilization.
• Meiotic divisions: Cell divisions producing gametes with half the chromosome number.
• Vegetative propagation: Asexual reproduction where new plants grow from vegetative parts like stem, root, or leaf.
Lead Question (2018):
Offsets are produced by:
(A) Parthenogenesis
(B) Meiotic divisions
(C) Parthenocarpy
(D) Mitotic divisions
Explanation:
The correct answer is (D) Mitotic divisions. Offsets are produced through mitotic divisions in vegetative parts of plants, creating genetically identical daughter plants. Parthenogenesis and parthenocarpy involve reproduction or fruit formation without fertilization, while meiotic divisions produce gametes, not offsets.
1. Which plant propagates naturally via offsets?
(A) Bryophyllum
(B) Banana
(C) Pistia
(D) Sugarcane
Explanation:
Correct answer is (B) Banana. Banana produces offsets (suckers) from its rhizome through mitotic divisions. These vegetative propagules grow into independent plants identical to the parent.
2. Parthenogenesis leads to:
(A) Fruit formation
(B) Seed formation without fertilization
(C) Vegetative growth
(D) Photosynthesis
Explanation:
Correct answer is (B) Seed formation without fertilization. Parthenogenesis is asexual reproduction where an embryo develops from an unfertilized egg. It does not produce offsets or vegetative propagules.
3. Parthenocarpy is characterized by:
(A) Seedless fruit
(B) Vegetative growth
(C) Formation of offsets
(D) Gamete formation
Explanation:
Correct answer is (A) Seedless fruit. Parthenocarpy is the development of fruits without fertilization, resulting in seedless fruits. It is unrelated to mitotic production of offsets.
4. Mitotic divisions result in:
(A) Genetically identical cells
(B) Halved chromosome number
(C) Fertilization
(D) Seedless fruit
Explanation:
Correct answer is (A) Genetically identical cells. Mitotic divisions produce identical cells, allowing vegetative propagation and formation of offsets in plants.
5. Which method of reproduction produces genetically identical offspring?
(A) Sexual reproduction
(B) Vegetative propagation
(C) Meiosis
(D) Pollination
Explanation:
Correct answer is (B) Vegetative propagation. Offsets are part of vegetative propagation, which relies on mitotic divisions to produce offspring identical to the parent plant.
6. Sugarcane propagates mainly through:
(A) Seeds
(B) Offsets
(C) Buds on stem cuttings
(D) Parthenocarpy
Explanation:
Correct answer is (C) Buds on stem cuttings. Sugarcane propagates via vegetative stem cuttings (suckers or offsets), where mitotic divisions produce new shoots identical to the parent.
7. Assertion-Reason Question:
Assertion (A): Offsets are produced by mitotic divisions.
Reason (R): Mitotic divisions create genetically identical cells for vegetative propagation.
(A) Both A and R true, R explains A
(B) Both A and R true, R does not explain A
(C) A true, R false
(D) A false, R true
Explanation:
Correct answer is (A). Offsets are formed via mitotic divisions. These divisions produce genetically identical cells, enabling vegetative propagation. Both assertion and reason are true, and the reason correctly explains the assertion.
8. Matching Type Question:
Match the plant with its vegetative propagation method:
(i) Bryophyllum – (a) Leaf buds
(ii) Sugarcane – (b) Stem cutting
(iii) Banana – (c) Suckers/Offsets
(iv) Potato – (d) Tubers
(A) i-a, ii-b, iii-c, iv-d
(B) i-b, ii-c, iii-d, iv-a
(C) i-c, ii-a, iii-b, iv-d
(D) i-d, ii-c, iii-a, iv-b
Explanation:
Correct answer is (A). Bryophyllum produces offsets from leaf buds, sugarcane propagates via stem cuttings, banana through suckers/offsets, and potato forms tubers. All involve mitotic divisions producing genetically identical new plants.
9. Fill in the Blanks:
Offsets are produced by ______ divisions, whereas gametes are produced by ______ divisions.
(A) Mitotic, Mitotic
(B) Mitotic, Meiotic
(C) Meiotic, Mitotic
(D) Meiotic, Meiotic
Explanation:
Correct answer is (B) Mitotic, Meiotic. Offsets arise from mitotic divisions in vegetative parts, producing identical cells. Gametes form via meiotic divisions, reducing the chromosome number for sexual reproduction.
10. Choose the correct statements:
(A) Offsets are asexual propagules
(B) Mitotic divisions produce offsets
(C) Parthenogenesis produces offsets
(D) Parthenocarpy produces seedless fruit
Options:
(1) A, B, D
(2) A, C, D
(3) B, C
(4) C, D
Explanation:
Correct answer is (1) A, B, D. Offsets are produced asexually by mitotic divisions. Parthenocarpy results in seedless fruit, while parthenogenesis produces embryos without fertilization but not offsets.
Subtopic: Double Fertilization
Keyword Definitions:
• Double fertilization: Unique process in angiosperms where one sperm fertilizes the egg forming zygote, and another fuses with two polar nuclei forming endosperm.
• Syngamy: Fusion of male and female gametes forming a zygote.
• Triploid endosperm: Tissue formed from fusion of second sperm with two polar nuclei, providing nutrition to developing embryo.
• Male gamete: Sperm cell from pollen tube.
• Polar nuclei: Two haploid nuclei in the central cell of embryo sac involved in forming endosperm.
Lead Question (2018):
Double fertilization is:
(A) Syngamy and triple fusion
(B) Fusion of two male gametes of a pollen tube with two different eggs
(C) Fusion of two male gametes with one egg
(D) Fusion of one male gamete with two polar nuclei
Explanation:
The correct answer is (A) Syngamy and triple fusion. Double fertilization involves one sperm fertilizing the egg (syngamy) forming zygote, and the second sperm fusing with two polar nuclei (triple fusion) to form triploid endosperm. This process is characteristic of angiosperms and ensures embryo nourishment.
1. Triploid endosperm is formed by:
(A) Fusion of sperm with egg
(B) Fusion of sperm with two polar nuclei
(C) Fusion of two eggs
(D) Fusion of two sperm
Explanation:
The correct answer is (B) Fusion of sperm with two polar nuclei. In double fertilization, the second sperm fuses with central cell's two polar nuclei, forming triploid endosperm, which provides nutrients to the developing embryo. This ensures proper seed development in angiosperms.
2. Which of the following is unique to angiosperms?
(A) Double fertilization
(B) Alternation of generations
(C) Binary fission
(D) Self-incompatibility
Explanation:
The correct answer is (A) Double fertilization. Only angiosperms exhibit double fertilization, producing zygote and triploid endosperm. Other plant groups do not form endosperm this way. This adaptation provides efficient nutrient supply to the embryo and is a key distinguishing feature of flowering plants.
3. Syngamy refers to:
(A) Fusion of polar nuclei
(B) Fusion of male and female gametes
(C) Formation of triploid tissue
(D) Fertilization by multiple pollen tubes
Explanation:
The correct answer is (B) Fusion of male and female gametes. In double fertilization, syngamy is the fusion of one sperm with egg to form diploid zygote. This is distinct from triple fusion where second sperm fuses with two polar nuclei forming endosperm.
4. How many sperm cells are involved in double fertilization?
(A) One
(B) Two
(C) Three
(D) Four
Explanation:
The correct answer is (B) Two. One sperm fuses with egg forming zygote, and the second fuses with two polar nuclei forming triploid endosperm. Two sperm cells from the pollen tube are sufficient for completing double fertilization in angiosperms.
5. The ploidy of endosperm formed in double fertilization is:
(A) Haploid
(B) Diploid
(C) Triploid
(D) Tetraploid
Explanation:
The correct answer is (C) Triploid. Triploid endosperm arises from fusion of one sperm (haploid) with two polar nuclei (haploid each), resulting in 3n tissue. It serves as nutritive tissue for embryo, supporting seed development and ensuring energy storage for germination.
6. Which part of the female gametophyte contains the polar nuclei?
(A) Egg cell
(B) Synergids
(C) Central cell
(D) Antipodal cells
Explanation:
The correct answer is (C) Central cell. Two haploid polar nuclei reside in central cell of embryo sac and fuse with second sperm to form triploid endosperm during double fertilization. Egg cell is fertilized separately to form zygote.
7. Assertion-Reason Question:
Assertion (A): Double fertilization produces both zygote and endosperm.
Reason (R): One sperm fuses with egg, second fuses with two polar nuclei.
(A) Both A and R true, R explains A
(B) Both A and R true, R does not explain A
(C) A true, R false
(D) A false, R true
Explanation:
Correct answer is (A). Double fertilization produces diploid zygote and triploid endosperm. The first sperm fertilizes egg, the second fuses with two polar nuclei, explaining how both zygote and endosperm are formed. This is a key concept in angiosperm reproduction.
8. Matching Type Question:
Match the structures with their roles in double fertilization:
(i) Egg cell – (a) Zygote formation
(ii) Sperm cell 1 – (b) Syngamy
(iii) Polar nuclei – (c) Endosperm formation
(iv) Sperm cell 2 – (d) Triple fusion
(A) i-a, ii-b, iii-c, iv-d
(B) i-b, ii-a, iii-d, iv-c
(C) i-a, ii-d, iii-c, iv-b
(D) i-c, ii-b, iii-a, iv-d
Explanation:
Correct answer is (A). Egg cell (i) forms zygote (a), sperm 1 (ii) participates in syngamy (b), polar nuclei (iii) form endosperm (c), and sperm 2 (iv) fuses in triple fusion (d). Matching reinforces understanding of double fertilization process.
9. Fill in the Blanks:
Double fertilization involves one sperm fertilizing the ______ and another sperm fusing with ______.
(A) Egg cell, central cell
(B) Polar nuclei, egg cell
(C) Antipodal cells, synergids
(D) Egg cell, egg cell
Explanation:
Correct answer is (A) Egg cell, central cell. One sperm fuses with egg to form zygote and second fuses with two polar nuclei in central cell forming triploid endosperm. This dual fertilization is characteristic of angiosperms and ensures proper embryo nutrition.
10. Choose the correct statements:
(A) Double fertilization is unique to angiosperms
(B) Triploid endosperm nourishes the embryo
(C) Two sperm cells participate
(D) Egg cell fuses with two sperm simultaneously
Options:
(1) A, B, C
(2) A, B, D
(3) B, C, D
(4) A, C, D
Explanation:
Correct answer is (1) A, B, C. Double fertilization occurs in angiosperms, forming zygote and triploid endosperm for nourishment. Two sperm cells are involved, but egg fuses with only one sperm. Understanding this mechanism is vital for NEET UG plant reproduction questions.
Topic: Pollination and Plant-Animal Interactions
Subtopic: Obligate Mutualism
Keyword Definitions:
• Obligate mutualism: A close ecological relationship where both species depend on each other for survival.
• Yucca: A plant that depends on yucca moths for pollination; neither can reproduce without the other.
• Yucca moth: A moth species whose larvae feed on yucca seeds; responsible for pollinating the plant.
• Hydrilla: Aquatic plant reproducing mainly vegetatively; not involved in obligate mutualism.
• Viola: Flowering plant pollinated by insects but not exclusively dependent on one species.
• Banana: Cultivated plant reproducing mainly vegetatively; pollination not dependent on a single animal.
Lead Question (2018):
Which one of the following plants shows a very close relationship with a species of moth, where none of the two can complete its life cycle without the other?
(A) Viola
(B) Hydrilla
(C) Banana
(D) Yucca
Explanation:
The correct answer is (D) Yucca. Yucca plants and yucca moths exhibit obligate mutualism; the moth pollinates the flower while laying eggs inside it. The larvae feed on some seeds, ensuring survival for both species. Neither can complete its life cycle without the other. This is a classic example of co-evolution.
1. Which of the following is an example of obligate mutualism?
(A) Yucca and yucca moth
(B) Hydrilla and fish
(C) Banana and bees
(D) Viola and butterflies
Explanation:
The correct answer is (A) Yucca and yucca moth. Obligate mutualism is a relationship where two species depend entirely on each other for survival or reproduction. Yucca plants require yucca moths for pollination, and moth larvae feed on some seeds. Other plant-animal interactions may be facultative or non-exclusive.
2. Yucca moth larvae feed on:
(A) Nectar
(B) Leaves
(C) Seeds of Yucca
(D) Pollen
Explanation:
The correct answer is (C) Seeds of Yucca. Yucca moth lays eggs inside the flower ovary; larvae consume a few seeds while allowing most seeds to develop. This ensures both moth survival and plant reproduction. Such species-specific mutualism exemplifies co-evolution and obligate dependence in nature.
3. Hydrilla reproduces mainly by:
(A) Seed formation
(B) Vegetative propagation
(C) Obligate mutualism
(D) Pollination by a specific insect
Explanation:
The correct answer is (B) Vegetative propagation. Hydrilla, an aquatic plant, reproduces through fragmentation and tubers, not relying on any specific pollinator. Unlike Yucca, it does not exhibit obligate mutualism. Understanding different reproductive strategies is key in plant ecology questions for NEET UG.
4. Viola plants are primarily pollinated by:
(A) Yucca moth
(B) Generalist insects
(C) Specific ants
(D) Birds only
Explanation:
The correct answer is (B) Generalist insects. Viola flowers attract various insect pollinators but are not dependent on a single species. This facultative relationship contrasts obligate mutualism, where species are entirely dependent on each other, as seen in Yucca and yucca moth.
5. Banana reproduction mainly occurs through:
(A) Vegetative methods
(B) Yucca moth pollination
(C) Wind pollination
(D) Obligate mutualism
Explanation:
The correct answer is (A) Vegetative methods. Cultivated bananas are typically seedless and propagate through suckers or tissue culture. They do not rely on pollination from a specific insect, unlike Yucca. NEET UG questions may focus on understanding plant reproduction strategies and differences between sexual and vegetative reproduction.
6. Yucca plants belong to which family?
(A) Liliaceae
(B) Musaceae
(C) Violaceae
(D) Hydrocharitaceae
Explanation:
The correct answer is (A) Liliaceae. Yucca, a perennial plant with sword-shaped leaves and white flowers, belongs to Liliaceae. Its obligate mutualism with yucca moths highlights evolutionary adaptations in Liliaceae species. Recognizing families and ecological interactions is important for NEET UG ecology and plant kingdom questions.
7. Assertion-Reason Question:
Assertion (A): Yucca cannot reproduce without yucca moth.
Reason (R): Yucca moth lays eggs in Yucca flowers while pollinating them.
(A) Both A and R are true, R explains A
(B) Both A and R are true, R does not explain A
(C) A true, R false
(D) A false, R true
Explanation:
Correct answer is (A). Yucca plants depend on yucca moths for pollination, and moths lay eggs inside the flowers. This interaction exemplifies obligate mutualism where reproduction of both species is intertwined. Such assertion-reason questions are common in NEET UG ecology.
8. Matching Type Question:
Match the plant with its ecological interaction:
(i) Yucca – (a) Obligate mutualism
(ii) Hydrilla – (b) Vegetative propagation
(iii) Banana – (c) Cultivated vegetative reproduction
(iv) Viola – (d) Facultative insect pollination
(A) i-a, ii-b, iii-c, iv-d
(B) i-b, ii-c, iii-a, iv-d
(C) i-c, ii-d, iii-a, iv-b
(D) i-d, ii-a, iii-b, iv-c
Explanation:
Correct answer is (A). Yucca exhibits obligate mutualism with yucca moth, Hydrilla reproduces vegetatively, Banana propagates vegetatively in cultivation, and Viola is pollinated by generalist insects. Matching tests understanding of ecological and reproductive strategies in plants.
9. Fill in the Blanks:
______ and yucca moth show obligate mutualism where both species depend on each other for survival.
(A) Hydrilla
(B) Viola
(C) Banana
(D) Yucca
Explanation:
Correct answer is (D) Yucca. Yucca and yucca moth exhibit obligate mutualism. The moth pollinates the flowers while laying eggs, and larvae feed on some seeds. This co-evolutionary relationship ensures survival and reproduction for both species, demonstrating species-specific mutual dependence.
10. Choose the correct statements:
(A) Yucca shows obligate mutualism
(B) Viola depends exclusively on one insect
(C) Hydrilla reproduces vegetatively
(D) Banana relies on yucca moth
Options:
(1) A, B, C
(2) A, C
(3) B, D
(4) A, B, D
Explanation:
Correct answer is (2) A, C. Yucca exhibits obligate mutualism with yucca moth, and Hydrilla reproduces vegetatively. Viola does not rely on a single insect, and Banana does not depend on yucca moth. Correctly distinguishing these relationships is essential for NEET UG ecology and plant reproduction questions.
Subtopic: Pollination Mechanisms
Keyword Definitions:
Single Ovule: Ovary containing only one ovule capable of forming a seed.
Inflorescence: Cluster of flowers arranged on a stem.
Pollination: Transfer of pollen from anther to stigma.
Biotic Pollination: Pollination by living agents such as insects, birds, or bats.
Abiotic Pollination: Pollination by non-living agents like wind or water.
Bee Pollination: Pollination carried out by bees, often in bright, scented flowers.
Bat Pollination: Pollination by bats, common in nocturnal or large flowers.
Wind Pollination: Transfer of pollen via air currents, typical in grasses.
Water Pollination: Transfer of pollen through water in aquatic plants.
Floral Adaptations: Structural traits facilitating effective pollination.
Clinical Significance: Knowledge of pollination is crucial for agriculture, seed yield, and maintaining biodiversity.
Lead Question - 2017
Flowers which have single ovule in the ovary and are packed into inflorescence are usually pollinated by:
(A) Bat
(B) Water
(C) Bee
(D) Wind
Explanation: Flowers with single ovules arranged in inflorescences are generally bee-pollinated. Bees are attracted to bright colors and scents and transfer pollen efficiently while collecting nectar. Wind and water pollination suit small or inconspicuous flowers, and bats pollinate large nocturnal flowers. Correct answer: C.
1. MCQ - Single Correct Answer
Which floral trait favors bee pollination?
(a) Strong scent and bright color
(b) Lack of nectar
(c) Small, inconspicuous flowers
(d) Flowers open at night
Explanation: Bee-pollinated flowers are bright and scented to attract bees, often providing nectar. Night-blooming flowers and inconspicuous blooms are adapted for bats or wind. This specialization increases pollination efficiency by targeting the preferred pollinator. Correct answer: a.
2. MCQ - Single Correct Answer
Inflorescence arrangement primarily increases:
(a) Seed dispersal
(b) Pollination efficiency
(c) Photosynthesis
(d) Root absorption
Explanation: Flower clustering into inflorescences enhances visibility to pollinators and increases pollen transfer efficiency. It does not directly affect photosynthesis, seed dispersal, or root absorption. Correct answer: b.
3. MCQ - Single Correct Answer (Clinical)
Decline in bee population most affects:
(a) Wind-pollinated crops
(b) Bee-pollinated crops
(c) Water-pollinated crops
(d) Night-blooming flowers
Explanation: Bee-pollinated crops like sunflower, mustard, and cucurbits depend on pollinators for fertilization. Decline in bee numbers reduces seed and fruit set, impacting food security and crop yield. Correct answer: b.
4. MCQ - Single Correct Answer
Which adaptation is typical of wind-pollinated flowers?
(a) Bright color
(b) Exposed stamens and stigma
(c) Nectar guides
(d) Strong scent
Explanation: Wind-pollinated flowers have exposed stamens and stigma to allow pollen to be carried by air currents. They usually lack bright colors, nectar, or strong scents since insects are not involved. Correct answer: b.
5. MCQ - Single Correct Answer
Which plant is an example of bee-pollination?
(a) Maize
(b) Sunflower
(c) Water lily
(d) Coconut
Explanation: Sunflower has many flowers in inflorescence, single ovule per floret, and produces nectar, making it bee-pollinated. Maize is wind-pollinated, water lily is water-pollinated, and coconut is mostly bat-pollinated. Correct answer: b.
6. MCQ - Single Correct Answer (Clinical)
Which pollination type is most affected by pesticide use?
(a) Wind
(b) Bee
(c) Water
(d) Bat
Explanation: Bee-pollination is sensitive to pesticides, which reduce bee populations and affect crop yields. Wind or water pollination is less impacted by chemicals. Proper management is crucial for maintaining pollinator health and food production. Correct answer: b.
7. MCQ - Assertion-Reason
Assertion (A): Wind-pollinated flowers are inconspicuous.
Reason (R): They rely on insects for pollination.
(a) Both A and R true, R correct explanation
(b) Both A and R true, R not correct explanation
(c) A true, R false
(d) A false, R true
Explanation: Wind-pollinated flowers are inconspicuous since they rely on air currents, not insects, for pollen transfer. Assertion true, reason false. Correct answer: c.
8. MCQ - Matching Type
Match pollination agent with flower type:
1. Bee - (a) Large nocturnal flowers
2. Bat - (b) Bright, scented flowers in inflorescence
3. Wind - (c) Small, inconspicuous flowers
Options:
(A) 1-b, 2-a, 3-c
(B) 1-a, 2-b, 3-c
(C) 1-c, 2-a, 3-b
(D) 1-b, 2-c, 3-a
Explanation: Bees prefer bright, scented flowers in inflorescence, bats pollinate large nocturnal flowers, and wind pollinates small, inconspicuous flowers. Correct matching: 1-b, 2-a, 3-c. Answer: A.
9. MCQ - Fill in the Blanks
Water-pollinated flowers are usually __________.
(a) Large and scented
(b) Submerged or floating
(c) Brightly colored
(d) Open at night
Explanation: Water-pollinated flowers are typically submerged or floating and produce pollen that travels on water surfaces. They do not require bright colors or scent since they rely on water movement for fertilization. Correct answer: b.
10. MCQ - Choose Correct Statements
Select correct statements about pollination:
1. Inflorescence arrangement increases pollination efficiency
2. Single ovule flowers can be bee-pollinated
3. Wind-pollinated flowers are usually colorful
4. Bat-pollinated flowers are nocturnal
Options:
(A) 1, 2, and 4
(B) 1 and 3
(C) 2 and 3
(D) All 1,2,3,4
Explanation: Inflorescence enhances pollination, single ovule flowers may be bee-pollinated, and bat-pollinated flowers are nocturnal. Wind-pollinated flowers are inconspicuous. Correct statements: 1, 2, and 4. Answer: A.
Subtopic: Megasporogenesis and Female Gametophyte
Keyword Definitions:
Functional Megaspore: The single surviving megaspore that develops into female gametophyte.
Embryo: Young multicellular organism formed after fertilization.
Ovule: Structure that develops into seed after fertilization.
Endosperm: Nutritive tissue supporting embryo growth.
Embryo Sac: Female gametophyte inside the ovule containing egg cell.
Megasporogenesis: Formation of megaspores by meiosis in the ovule.
Megagametogenesis: Development of functional megaspore into embryo sac.
Fertilization: Fusion of male and female gametes.
Double Fertilization: Unique process in angiosperms forming zygote and endosperm.
Synergids: Cells in embryo sac that guide pollen tube.
Antipodal Cells: Cells at chalazal end of embryo sac with nutritive function.
Lead Question - 2017
Functional megaspore in an angiosperm develops into:
(A) Embryo
(B) Ovule
(C) Endosperm
(D) Embryo sac
Explanation: The functional megaspore undergoes mitotic divisions to form the embryo sac, which is the female gametophyte containing egg, synergids, polar nuclei, and antipodals. Fertilization occurs here, leading to zygote and endosperm formation. Therefore, correct answer is D.
1. MCQ - Single Correct Answer
Which cell in the embryo sac fuses with sperm to form the zygote?
(a) Synergid
(b) Egg cell
(c) Central cell
(d) Antipodal cell
Explanation: The egg cell located within the embryo sac fuses with one sperm cell during fertilization to form the zygote. Synergids guide pollen tube, central cell forms endosperm, antipodals have nutritive role. Answer: b.
2. MCQ - Single Correct Answer
Which process leads to the formation of the functional megaspore?
(a) Fertilization
(b) Megasporogenesis
(c) Pollination
(d) Germination
Explanation: Megasporogenesis is the meiotic division of the megaspore mother cell producing four megaspores, of which only one survives as the functional megaspore. This megaspore undergoes mitosis to form embryo sac. Answer: b.
3. MCQ - Single Correct Answer (Clinical)
A plant shows failure in embryo sac formation. Which reproductive issue occurs?
(a) Self-pollination
(b) Fertilization failure
(c) Seed dormancy
(d) Double fertilization
Explanation: Without a functional embryo sac, the egg cell is absent, causing fertilization failure even if pollen reaches the ovule. This leads to infertility or non-viable seeds. Answer: b.
4. MCQ - Single Correct Answer
Which cells in the embryo sac guide the pollen tube to the egg?
(a) Antipodal cells
(b) Synergids
(c) Polar nuclei
(d) Egg cell
Explanation: Synergids flank the egg cell and produce chemical attractants guiding the pollen tube for successful fertilization. Polar nuclei form endosperm, antipodals are nutritive, egg is fertilized. Answer: b.
5. MCQ - Single Correct Answer
How many nuclei are present in a mature Polygonum-type embryo sac?
(a) 6
(b) 7
(c) 8
(d) 9
Explanation: The mature Polygonum-type embryo sac contains 8 nuclei: 3 at micropylar end (egg and synergids), 3 at chalazal end (antipodals), and 2 polar nuclei in the center forming primary endosperm nucleus. Answer: c.
6. MCQ - Single Correct Answer (Clinical)
Which abnormality occurs if more than one megaspore develops into embryo sac?
(a) Polyembryony
(b) Sterility
(c) Parthenocarpy
(d) Cross-pollination
Explanation: If multiple megaspores form embryo sacs, multiple eggs may develop, leading to polyembryony, where more than one embryo grows within a single seed. It affects seed morphology and germination. Answer: a.
7. MCQ - Assertion-Reason
Assertion (A): Endosperm is triploid.
Reason (R): It forms after fusion of one sperm with two polar nuclei.
(a) Both A and R true, R correct explanation
(b) Both A and R true, R not correct explanation
(c) A true, R false
(d) A false, R true
Explanation: The endosperm is triploid, formed by fusion of one sperm with two polar nuclei in the central cell. Both assertion and reason are correct, and reason explains assertion. Answer: a.
8. MCQ - Matching Type
Match the following:
1. Egg cell - (a) Forms endosperm
2. Central cell - (b) Fertilized to form zygote
3. Synergids - (c) Guide pollen tube
Options:
(A) 1-b, 2-a, 3-c
(B) 1-c, 2-b, 3-a
(C) 1-a, 2-b, 3-c
(D) 1-b, 2-c, 3-a
Explanation: The egg cell forms zygote, central cell fuses with sperm to form endosperm, and synergids guide the pollen tube. Correct matching: 1-b, 2-a, 3-c. Answer: A.
9. MCQ - Fill in the Blanks
The central cell of the embryo sac contains __________ nuclei before fertilization.
(a) Two
(b) One
(c) Three
(d) Four
Explanation: The central cell at the center of the embryo sac which fuse with one sperm to form triploid endosperm. This is essential for nourishing the developing embryo. Answer: a.
10. MCQ - Choose Correct Statements
Select correct statements about embryo sac:
1. It is the female gametophyte
2. Contains eight nuclei
3. Egg cell is fertilized to form endosperm
4. Synergids guide pollen tube
Options:
(A) 1, 2, and 4
(B) 1 and 3
(C) 2, 3, and 4
(D) All 1,2,3,4
Explanation: Embryo sac is the female gametophyte containing eight nuclei. Egg forms zygote, not endosperm, and synergids guide pollen tube. Correct statements are 1, 2, and 4. Answer: A.
Topic: Pollination Biology
Subtopic: Pollination Mechanisms
Keyword Definitions:
• Cleistogamy – Self-pollination within closed flowers.
• Anemophily – Pollination by wind.
• Entomophily – Pollination by insects.
• Hydrophily – Pollination by water.
• Pollination – Transfer of pollen from anther to stigma.
• Attractants – Features like color, scent, or nectar that attract pollinators.
• Rewards – Nectar or pollen provided to pollinators as incentive.
• Stigma – Female receptive part of flower.
• Anther – Male part producing pollen.
• Gamete – Male or female reproductive cell.
Lead Question – 2017:
Attractants and rewards are required for:
(A) Cleistogamy
(B) Anemophily
(C) Entomophily
(D) Hydrophily
Explanation:
Entomophily involves insect-mediated pollination where flowers use attractants (color, scent) and rewards (nectar, pollen) to lure insects. Cleistogamy occurs without pollinators, anemophily uses wind, and hydrophily uses water. These mechanisms do not require attractants or rewards. (Answer: C)
1) Single Correct Answer MCQ:
Which feature is most effective in attracting insect pollinators?
(A) Bright petals
(B) Small green sepals
(C) Smooth stems
(D) Underground roots
Explanation:
Bright petals serve as visual attractants for insects, guiding them to flowers for pollination. Other features like sepals, stems, or roots are not involved in attracting pollinators. (Answer: A)
2) Single Correct Answer MCQ:
Which reward is commonly offered by entomophilous flowers?
(A) Water
(B) Nectar
(C) Air currents
(D) Sunlight
Explanation:
Nectar is a sugary reward provided by flowers to attract insect pollinators, encouraging repeated visits and effective pollen transfer. Water, air, or sunlight do not serve as pollinator rewards. (Answer: B)
3) Single Correct Answer MCQ:
Wind-pollinated flowers usually:
(A) Provide nectar
(B) Have brightly colored petals
(C) Produce large amounts of pollen
(D) Emit strong fragrance
Explanation:
Wind-pollinated (anemophilous) flowers produce abundant pollen for dispersal by air currents. They are generally small, colorless, and scentless, as they do not rely on attractants or rewards. (Answer: C)
4) Single Correct Answer MCQ:
Which pollination type occurs in underwater plants?
(A) Entomophily
(B) Cleistogamy
(C) Hydrophily
(D) Anemophily
Explanation:
Hydrophily involves pollen transport through water. Attractants and rewards are unnecessary, as pollinators are absent, and water currents facilitate pollination. (Answer: C)
5) Single Correct Answer MCQ:
Cleistogamous flowers are characterized by:
(A) Self-pollination within closed flowers
(B) Bright petals for insect attraction
(C) Production of nectar
(D) Pollen dispersed by wind
Explanation:
Cleistogamy is self-pollination occurring in closed flowers. Attractants and rewards are not required because pollinators are not involved. This ensures reproductive success without dependence on environmental agents. (Answer: A)
6) Single Correct Answer MCQ:
Which flower adaptation reduces the need for pollinator visits?
(A) Entomophily
(B) Cleistogamy
(C) Bright colors
(D) Nectar production
Explanation:
Cleistogamy allows automatic self-pollination inside closed flowers, removing reliance on external agents or attractants, unlike entomophily where colors and nectar are crucial. (Answer: B)
7) Assertion-Reason MCQ:
Assertion (A): Entomophilous flowers produce nectar.
Reason (R): Nectar serves as a reward to attract pollinators.
(A) Both A and R true, R explains A
(B) Both A and R true, R does not explain A
(C) A true, R false
(D) A false, R true
Explanation:
Both A and R are true. Nectar is produced specifically as a reward for insects, ensuring pollination. It explains the mechanism of attraction in entomophily. (Answer: A)
8) Matching Type MCQ:
Match the pollination type with characteristic:
1. Cleistogamy – (i) Self-pollination
2. Entomophily – (ii) Attractants and rewards
3. Anemophily – (iii) Wind-dispersed pollen
4. Hydrophily – (iv) Water-mediated pollen
Options:
(A) 1-i, 2-ii, 3-iii, 4-iv
(B) 1-ii, 2-i, 3-iv, 4-iii
(C) 1-iii, 2-iv, 3-i, 4-ii
(D) 1-iv, 2-iii, 3-ii, 4-i
Explanation:
Correct matching: 1-i, 2-ii, 3-iii, 4-iv. Each pollination type corresponds to its mechanism and reliance on attractants or environmental factors. (Answer: A)
9) Fill in the Blanks MCQ:
Flowers with ______ rely on insects for pollination.
(A) Anemophily
(B) Cleistogamy
(C) Entomophily
(D) Hydrophily
Explanation:
Flowers with entomophily rely on insects, employing attractants and rewards to facilitate pollination. Other types like wind, water, or cleistogamous flowers do not require insects. (Answer: C)
10) Choose the correct statements MCQ:
1. Entomophily requires attractants
2. Hydrophily requires nectar
3. Anemophily uses wind
4. Cleistogamy occurs in closed flowers
Options:
(A) 1, 3, 4
(B) 1, 2, 3
(C) 2, 3, 4
(D) 1, 2, 4
Explanation:
Statements 1, 3, 4 are correct. Entomophily uses attractants and rewards, anemophily uses wind, and cleistogamy occurs in closed flowers without pollinators. Hydrophily does not require nectar. (Answer: A)
Topic: Sexual Reproduction in Plants
Subtopic: Double Fertilization
Keyword Definitions:
• Double fertilization – Fusion of one male gamete with egg and another with central cell.
• Angiosperms – Flowering plants with seeds enclosed in fruits.
• Gymnosperms – Seed plants with naked seeds, no fruits.
• Gamete – Male or female reproductive cell.
• Fertilization – Fusion of male and female gametes.
• Zygote – Diploid cell formed by fusion of egg and sperm.
• Endosperm – Triploid tissue formed in angiosperms providing nourishment.
• Ovule – Structure containing female gametophyte in seed plants.
• Embryo sac – Female gametophyte in angiosperms.
• Syngamy – Another term for fusion of gametes.
Lead Question – 2017:
Double fertilization is exhibited by:
(A) Angiosperms
(B) Gymnosperms
(C) Algae
(D) Fungi
Explanation:
Double fertilization occurs in angiosperms, where one male gamete fuses with the egg forming a zygote, and another fuses with the central cell forming endosperm. Gymnosperms, algae, and fungi do not exhibit this process. It is crucial for seed development in flowering plants. (Answer: A)
1) Single Correct Answer MCQ:
Which structure in angiosperms receives the pollen?
(A) Ovule
(B) Stigma
(C) Style
(D) Petal
Explanation:
The stigma is the receptive part of the pistil where pollen grains land, allowing germination and pollen tube growth toward ovule for fertilization. (Answer: B)
2) Single Correct Answer MCQ:
The endosperm formed after double fertilization is:
(A) Haploid
(B) Diploid
(C) Triploid
(D) Tetraploid
Explanation:
Endosperm in angiosperms is triploid, resulting from fusion of one male gamete with two polar nuclei in the central cell. It nourishes the developing embryo. (Answer: C)
3) Single Correct Answer MCQ:
Which male gamete fuses with the egg?
(A) One of the two sperm
(B) Central cell sperm
(C) Pollen tube nucleus
(D) Vegetative cell
Explanation:
One of the two male gametes in the pollen tube fuses with the egg cell to form the zygote, while the second fuses with central cell nuclei. (Answer: A)
4) Single Correct Answer MCQ:
Double fertilization ensures:
(A) Only embryo formation
(B) Only endosperm formation
(C) Both embryo and endosperm formation
(D) Only pollen germination
Explanation:
Double fertilization produces both the zygote (embryo) and triploid endosperm, which provides nourishment to the embryo. This is unique to angiosperms. (Answer: C)
5) Single Correct Answer MCQ:
Which part of the angiosperm female gametophyte contains the egg?
(A) Central cell
(B) Antipodal cells
(C) Egg apparatus
(D) Synergids
Explanation:
The egg apparatus contains the egg cell and synergids, located at the micropylar end of the embryo sac, where fertilization occurs. (Answer: C)
6) Single Correct Answer MCQ:
Which group of plants does not show double fertilization?
(A) Angiosperms
(B) Gymnosperms
(C) Monocots
(D) Dicots
Explanation:
Gymnosperms lack double fertilization; they produce free nuclear endosperm or none, unlike angiosperms which show double fertilization. Monocots and dicots are angiosperms, so they exhibit it. (Answer: B)
7) Assertion-Reason MCQ:
Assertion (A): Double fertilization is characteristic of angiosperms.
Reason (R): It produces both zygote and endosperm for embryo nourishment.
(A) Both A and R true, R explains A
(B) Both A and R true, R does not explain A
(C) A true, R false
(D) A false, R true
Explanation:
Both A and R are true. Double fertilization is unique to angiosperms and produces the zygote and endosperm, providing essential nutrition for embryo development. (Answer: A)
8) Matching Type MCQ:
Match:
1. Zygote – (i) Formed by egg + sperm
2. Endosperm – (ii) Formed by sperm + central cell nuclei
3. Embryo sac – (iii) Female gametophyte
Options:
(A) 1-i, 2-ii, 3-iii
(B) 1-ii, 2-i, 3-iii
(C) 1-i, 2-iii, 3-ii
(D) 1-iii, 2-ii, 3-i
Explanation:
Correct matching: 1-i (zygote), 2-ii (endosperm), 3-iii (embryo sac). This shows the process of double fertilization clearly in angiosperms. (Answer: A)
9) Fill in the Blanks MCQ:
In double fertilization, one male gamete fuses with ______ to form the endosperm.
(A) Egg
(B) Synergid
(C) Central cell
(D) Antipodal cell
Explanation:
One male gamete fuses with the central cell containing two polar nuclei to form the triploid endosperm, essential for nourishing the developing embryo. (Answer: C)
10) Choose the correct statements MCQ:
1. Double fertilization is found in all angiosperms
2. One male gamete fuses with egg
3. One male gamete fuses with central cell
4. Gymnosperms show double fertilization
Options:
(A) 1, 2, 3
(B) 2, 3, 4
(C) 1, 4
(D) 2, 4
Explanation:
Statements 1, 2, 3 are correct. Gymnosperms do not show double fertilization. Angiosperms exhibit one gamete + egg = zygote, other gamete + central cell = endosperm. (Answer: A)
Topic: Types of Flowering Plants
Subtopic: Dioecious Plants and Pollination
Keyword Definitions:
• Dioecious – Plants with male and female flowers on separate individuals; prevents self-pollination.
• Cleistogamy – Flowers that do not open, resulting in self-pollination.
• Autogamy – Self-pollination within the same flower.
• Geitonogamy – Transfer of pollen between different flowers of the same plant.
• Xenogamy – Cross-pollination between flowers of different plants.
• Pollination – Transfer of pollen from anther to stigma enabling fertilization.
• Clinical/agronomic relevance – Dioecious plants enhance genetic diversity, reduce inbreeding, and are important in breeding programs.
Lead Question – 2017:
A dioecious flowering plant prevents both
(A) Cleistogamy and xenogamy
(B) Autogamy and xenogamy
(C) Autogamy and geitonogamy
(D) Geitonogamy and Xenogamy
Explanation:
Dioecious plants have male and female flowers on separate plants, making autogamy and geitonogamy impossible. Self-pollination (autogamy) and pollen transfer between flowers of the same plant (geitonogamy) are prevented, while cross-pollination (xenogamy) occurs naturally. This promotes genetic variation. (Answer: C)
1) Which of the following ensures cross-pollination in flowers?
(A) Dioecy
(B) Cleistogamy
(C) Autogamy
(D) Geitonogamy
Explanation:
Dioecy ensures cross-pollination since male and female flowers are on separate plants. It prevents self-pollination mechanisms like autogamy and geitonogamy, increasing genetic diversity. Cleistogamy involves selfing in closed flowers, unsuitable for cross-pollination. This feature is important in horticulture and plant breeding programs. (Answer: A)
2) A flower that never opens but self-pollinates is called:
(A) Chasmogamous
(B) Cleistogamous
(C) Dioecious
(D) Monoecious
Explanation:
Cleistogamous flowers remain closed and self-pollinate, ensuring seed production without insect or wind assistance. Unlike chasmogamous flowers, which open and may cross-pollinate, cleistogamy reduces genetic variation but guarantees reproduction in unfavorable conditions. (Answer: B)
3) Clinical/agronomic case: A dioecious plant population shows reduced seed set due to low male plants. The likely reason is:
(A) Excess autogamy
(B) Limited xenogamy
(C) Increased geitonogamy
(D) Cleistogamy failure
Explanation:
Low male plants reduce xenogamy, the cross-pollination between different individuals. Dioecious plants rely on male and female individuals for fertilization. Inadequate male population limits pollen availability, lowering seed production. Proper sex ratio management is crucial in cultivation of dioecious crops. (Answer: B)
4) Which pollination occurs between flowers of different plants of the same species?
(A) Autogamy
(B) Geitonogamy
(C) Xenogamy
(D) Cleistogamy
Explanation:
Xenogamy is cross-pollination between flowers of different plants of the same species, promoting genetic variation. Autogamy and geitonogamy are forms of self-pollination. Xenogamy requires pollinators or wind for pollen transfer and is important for crop improvement and biodiversity conservation. (Answer: C)
5) Geitonogamy is:
(A) Cross-pollination between plants
(B) Self-pollination between flowers of same plant
(C) Fertilization without pollen
(D) Pollination in dioecious plants only
Explanation:
Geitonogamy is the transfer of pollen between flowers of the same plant. It is a form of self-pollination, unlike xenogamy which occurs between different plants. Dioecious plants prevent geitonogamy naturally, enhancing outcrossing and genetic diversity. (Answer: B)
6) Monoecious plants have:
(A) Male and female flowers on separate plants
(B) Male and female flowers on the same plant
(C) Only male flowers
(D) Only female flowers
Explanation:
Monoecious plants bear both male and female flowers on the same plant, allowing self-pollination like geitonogamy. Examples include maize and cucumber. Dioecious plants differ by having separate male and female individuals, preventing autogamy and geitonogamy. This distinction is important for breeding and horticultural management. (Answer: B)
7) Assertion-Reason type:
Assertion (A): Dioecious plants always promote genetic diversity.
Reason (R): They prevent self-pollination mechanisms like autogamy and geitonogamy.
(A) Both A and R are true, and R is the correct explanation of A
(B) Both A and R are true, but R is not the correct explanation
(C) A is true, R is false
(D) A is false, R is true
Explanation:
Both assertion and reason are true, and R correctly explains A. Dioecious plants prevent self-pollination by separating male and female flowers on different plants, ensuring cross-pollination and increased genetic variation, which is advantageous in breeding and evolution. (Answer: A)
8) Matching type:
Match plant types with characteristics:
(A) Dioecious – (i) Male and female on separate plants
(B) Monoecious – (ii) Male and female on same plant
(C) Cleistogamous – (iii) Closed flowers self-pollinate
(D) Chasmogamous – (iv) Open flowers for cross-pollination
Options:
(A) A-i, B-ii, C-iii, D-iv
(B) A-ii, B-i, C-iv, D-iii
(C) A-iii, B-iv, C-i, D-ii
(D) A-iv, B-iii, C-ii, D-i
Explanation:
Correct matches: Dioecious – male/female on separate plants, Monoecious – male/female on same plant, Cleistogamous – closed flowers self-pollinate, Chasmogamous – open flowers for cross-pollination. These distinctions are crucial for understanding reproductive strategies and improving crop breeding. (Answer: A)
9) Fill in the blanks:
Flowers that self-pollinate without opening are called ______ flowers.
(A) Chasmogamous
(B) Cleistogamous
(C) Dioecious
(D) Monoecious
Explanation:
Cleistogamous flowers remain closed and self-pollinate. This ensures reproduction under unfavorable conditions but limits genetic diversity. In contrast, dioecious and chasmogamous flowers allow outcrossing and increased variation. Cleistogamy is a reproductive adaptation in some plants for survival and seed production. (Answer: B)
10) Choose the correct statements:
1. Dioecious plants prevent autogamy and geitonogamy.
2. Monoecious plants allow geitonogamy.
3. Cleistogamous flowers are open for cross-pollination.
4. Xenogamy promotes genetic diversity.
(A) 1, 2, 4 only
(B) 2 and 3 only
(C) 1 and 3 only
(D) All are correct
Explanation:
Statements 1, 2, and 4 are correct; statement 3 is wrong because cleistogamous flowers remain closed. Dioecious plants prevent self-pollination, monoecious plants can allow geitonogamy, and xenogamy increases genetic diversity. These distinctions are vital for plant reproduction and breeding strategies. (Answer: A)
Topic: Embryology of Angiosperms
Subtopic: Ovule Structure and Function
Keyword Definitions:
• Ovule: Structure in ovary of angiosperms that develops into a seed after fertilization.
• Megaspore: Haploid cell formed after meiosis of megaspore mother cell; develops into embryo sac.
• Megasporangium: Tissue enclosing the megaspore mother cell, also called nucellus.
• Megasporophyll: Leaf-like structure bearing one or more ovules.
• Megaspore Mother Cell: Diploid cell that undergoes meiosis to produce haploid megaspores.
Lead Question - 2016 (Phase 2):
The ovule of an angiosperm is technically equivalent to:
(1) Megaspore
(2) Megasporangium
(3) Megasporophyll
(4) Megaspore mother cell
Explanation: In angiosperms, the ovule consists of nucellus (megasporangium) surrounded by integuments. Therefore, technically, the ovule is equivalent to the megasporangium, as it contains the megaspore mother cell which gives rise to the functional megaspore. Correct answer: (2) Megasporangium, essential NEET UG embryology concept.
1. Single Correct Answer MCQ:
Which part of ovule develops into seed coat after fertilization?
(1) Nucellus
(2) Integuments
(3) Funiculus
(4) Micropyle
Explanation: The integuments of ovule harden to form the seed coat after fertilization. Nucellus becomes perisperm in some plants. Correct answer: (2) Integuments, key NEET UG embryology fact.
2. Single Correct Answer MCQ:
Micropyle is located at the:
(1) Chalazal end of ovule
(2) Funicular end of ovule
(3) Tip of integuments
(4) Center of nucellus
Explanation: Micropyle is a small opening at the tip of integuments, opposite the chalaza, allowing pollen tube entry. Correct answer: (3) Tip of integuments, important NEET UG embryology concept.
3. Single Correct Answer MCQ:
The structure that directly gives rise to female gametophyte is:
(1) Ovule
(2) Nucellus
(3) Megaspore mother cell
(4) Integument
Explanation: The megaspore mother cell within nucellus undergoes meiosis to produce megaspores, one of which develops into the female gametophyte (embryo sac). Correct answer: (3) Megaspore mother cell, essential NEET UG embryology fact.
4. Single Correct Answer MCQ:
Which part of ovule is usually haploid after meiosis?
(1) Nucellus
(2) Integuments
(3) Functional megaspore
(4) Funiculus
Explanation: One of the four megaspores produced by meiosis of megaspore mother cell remains functional and is haploid, developing into embryo sac. Correct answer: (3) Functional megaspore, important NEET UG embryology topic.
5. Single Correct Answer MCQ (Clinical-type):
Failure of integument formation may lead to:
(1) Seedless ovule
(2) Malformed seed coat
(3) Incomplete fertilization
(4) Non-viable megaspore
Explanation: Integuments develop into seed coat; their absence or malformation results in incomplete protection of embryo, causing defective or malformed seeds. Correct answer: (2) Malformed seed coat, clinically relevant NEET UG point.
6. Single Correct Answer MCQ:
Chalaza is the region where:
(1) Funiculus attaches
(2) Micropyle is present
(3) Embryo sac forms
(4) Nucellus degenerates
Explanation: Chalaza is the basal region of ovule opposite to micropyle where nucellus and integuments meet, and funiculus attaches. Correct answer: (1) Funiculus attaches, essential NEET UG embryology knowledge.
7. Assertion-Reason MCQ:
Assertion (A): Ovule is equivalent to megasporangium.
Reason (R): Ovule contains megaspore mother cell inside nucellus, surrounded by integuments.
(1) Both A and R are true and R explains A
(2) Both A and R are true but R does not explain A
(3) A is true but R is false
(4) A is false but R is true
Explanation: Ovule is equivalent to megasporangium because nucellus houses the megaspore mother cell. Integuments surround it, but the core functional unit is the megasporangium. Correct answer: (1) Both A and R are true and R explains A.
8. Matching Type MCQ:
Match ovule parts with function:
A. Nucellus
B. Integuments
C. Funiculus
D. Micropyle
1. Seed coat formation
2. Attachment to ovary
3. Nutrient tissue for embryo sac
4. Entry for pollen tube
Options:
(1) A-3, B-1, C-2, D-4
(2) A-1, B-2, C-3, D-4
(3) A-4, B-3, C-2, D-1
(4) A-3, B-2, C-1, D-4
Explanation: Nucellus provides nutrients to embryo sac (A-3), integuments form seed coat (B-1), funiculus attaches ovule to ovary (C-2), and micropyle allows pollen tube entry (D-4). Correct answer: (1) A-3, B-1, C-2, D-4.
9. Fill in the Blanks MCQ:
The diploid cell inside nucellus that undergoes meiosis is ______.
(1) Megaspore
(2) Megaspore mother cell
(3) Embryo sac
(4) Integument
Explanation: The megaspore mother cell inside nucellus undergoes meiosis to form haploid megaspores, one of which develops into the embryo sac. Correct answer: (2) Megaspore mother cell.
10. Choose the Correct Statements MCQ:
Select correct statements:
(1) Ovule is technically a megasporangium
(2) Funiculus attaches ovule to ovary
(3) Micropyle allows pollen tube entry
(4) Embryo sac develops from integuments
Options:
(1) 1, 2, 3 only
(2) 1, 2, 4 only
(3) All statements are correct
(4) 2, 3, 4 only
Explanation: Statements 1, 2, 3 are correct. Embryo sac develops from functional megaspore, not integuments. Funiculus, micropyle, and ovule as megasporangium are accurate NEET UG points. Correct answer: (1) 1, 2, 3 only.
Topic: Pollination
Subtopic: Agents of Pollination in Aquatic Plants
Keyword Definitions:
• Pollination: Transfer of pollen from anther to stigma of a flower for fertilization.
• Water Pollination: Pollination occurring through water currents, rare in angiosperms.
• Insect Pollination: Transfer of pollen via insects; also called entomophily.
• Wind Pollination: Transfer of pollen through air currents; also called anemophily.
• Aquatic Plants: Plants living in or on water surfaces; may show special pollination adaptations.
Lead Question - 2016 (Phase 2):
Pollination in water hyacinth and water lily is brought about by the agency of:
(1) Bats
(2) Water
(3) Insects or wind
(4) Birds
Explanation: Water hyacinth and water lily are primarily pollinated by insects, though some may also be wind-pollinated. Water is not the main agent. Bats and birds do not usually visit these aquatic flowers. Correct answer: (3) Insects or wind, essential for NEET UG understanding of pollination mechanisms.
1. Single Correct Answer MCQ:
Which of the following is entomophilous?
(1) Grass
(2) Sunflower
(3) Rice
(4) Wheat
Explanation: Sunflower is entomophilous, meaning it is pollinated by insects, whereas grass, rice, and wheat are mostly wind-pollinated. Correct answer: (2) Sunflower, important NEET UG pollination topic.
2. Single Correct Answer MCQ:
Anemophilous flowers are usually:
(1) Large and colorful
(2) Small and inconspicuous
(3) Fragrant
(4) Nectar-rich
Explanation: Wind-pollinated (anemophilous) flowers are typically small, inconspicuous, and lack nectar or fragrance. Correct answer: (2) Small and inconspicuous, essential NEET UG floral adaptation fact.
3. Single Correct Answer MCQ:
Hydrophily refers to pollination by:
(1) Wind
(2) Insects
(3) Water
(4) Birds
Explanation: Hydrophily is pollination via water currents, a rare adaptation in aquatic plants. Correct answer: (3) Water, important NEET UG pollination concept.
4. Single Correct Answer MCQ:
Which agent primarily pollinates water hyacinth?
(1) Birds
(2) Insects
(3) Wind
(4) Bats
Explanation: Water hyacinth is mainly insect-pollinated. Some incidental wind-pollination occurs but birds and bats are not involved. Correct answer: (2) Insects, critical NEET UG aquatic plant pollination knowledge.
5. Single Correct Answer MCQ (Clinical-type):
Allergic pollen causing hay fever is mostly from:
(1) Hydrophilous plants
(2) Entomophilous plants
(3) Anemophilous plants
(4) Ornithophilous plants
Explanation: Hay fever is triggered mainly by wind-pollinated (anemophilous) plants like grasses and trees, because their pollen is airborne. Correct answer: (3) Anemophilous plants, clinically relevant for NEET UG.
6. Single Correct Answer MCQ:
Nectar guides in flowers are adaptations for:
(1) Wind pollination
(2) Water pollination
(3) Insect pollination
(4) Self-pollination
Explanation: Nectar guides are visual cues for insects, enhancing pollination efficiency. Correct answer: (3) Insect pollination, important NEET UG floral adaptation topic.
7. Assertion-Reason MCQ:
Assertion (A): Water lily flowers can be pollinated by insects or wind.
Reason (R): Their bright petals attract insects while light pollen may disperse via wind.
(1) Both A and R are true and R explains A
(2) Both A and R are true but R does not explain A
(3) A is true but R is false
(4) A is false but R is true
Explanation: Both assertion and reason are correct. Bright petals attract insects, and light pollen can disperse by wind, explaining the dual pollination mechanism. Correct answer: (1) Both A and R are true and R explains A.
8. Matching Type MCQ:
Match plant with pollination agent:
A. Water hyacinth
B. Grass
C. Hibiscus
D. Coconut
1. Insects
2. Wind
3. Insects
4. Wind
Options:
(1) A-1, B-2, C-3, D-4
(2) A-2, B-1, C-3, D-4
(3) A-1, B-1, C-2, D-4
(4) A-2, B-2, C-1, D-3
Explanation: Water hyacinth (A-1) and hibiscus (C-3) are insect-pollinated; grass (B-2) and coconut (D-4) are wind-pollinated. Correct answer: (1) A-1, B-2, C-3, D-4.
9. Fill in the Blanks MCQ:
Bright petals and nectar are adaptations for ______.
(1) Wind pollination
(2) Insect pollination
(3) Water pollination
(4) Self-pollination
Explanation: Bright petals and nectar attract insects, enhancing insect-mediated pollination. Correct answer: (2) Insect pollination, key NEET UG pollination adaptation.
10. Choose the Correct Statements MCQ:
Select correct statements:
(1) Water hyacinth is entomophilous
(2) Water lily may also be wind-pollinated
(3) Hydrophily is common in most angiosperms
(4) Nectar and bright petals attract insects
Options:
(1) 1, 2, 4 only
(2) 1, 3, 4 only
(3) All statements are correct
(4) 2, 3, 4 only
Explanation: Statements 1, 2, and 4 are correct. Hydrophily is rare, not common. Water hyacinth is insect-pollinated, water lily can use insects or wind, and nectar plus bright petals attract insects. Correct answer: (1) 1, 2, 4 only.
Topic: Embryology of Angiosperms
Subtopic: Female Gametophyte and Megasporogenesis
Keyword Definitions:
• Embryo Sac: Female gametophyte of angiosperms containing egg cell, synergids, central cell, and antipodals.
• Filiform Apparatus: Specialized structure in synergids guiding pollen tube entry.
• Antipodal Cells: Cells at the chalazal end of embryo sac, often 3 in number.
• Megaspore Mother Cell: Diploid cell undergoing meiosis to form haploid megaspores.
• Reduction Division: Meiosis that reduces chromosome number by half, essential in gamete formation.
Lead Question - 2016 (Phase 2):
In majority of angiosperms:
(1) A small central cell is present in the embryo sac
(2) Egg has a filiform apparatus
(3) There are numerous antipodal cells
(4) Reduction division occurs in the megaspore mother cells
Explanation: In angiosperms, the megaspore mother cell undergoes meiosis (reduction division) producing haploid megaspores. Other statements are incorrect: central cell is large, filiform apparatus is in synergids not egg, and antipodal cells are usually three. Correct answer: (4) Reduction division occurs in the megaspore mother cells, essential NEET UG concept.
1. Single Correct Answer MCQ:
Which structure in the embryo sac receives the pollen tube?
(1) Egg cell
(2) Synergid
(3) Central cell
(4) Antipodal cell
Explanation: The synergid contains the filiform apparatus which guides the pollen tube to the egg apparatus. Correct answer: (2) Synergid, critical for NEET UG angiosperm fertilization.
2. Single Correct Answer MCQ:
How many functional megaspores are usually present in angiosperms?
(1) One
(2) Two
(3) Three
(4) Four
Explanation: Only one of the four haploid megaspores formed after meiosis remains functional and develops into the embryo sac. Correct answer: (1) One, important NEET UG embryology concept.
3. Single Correct Answer MCQ:
Which cell of embryo sac fuses with male gamete to form endosperm?
(1) Egg cell
(2) Synergid
(3) Central cell
(4) Antipodal
Explanation: The central cell containing two polar nuclei fuses with a male gamete to form triploid endosperm. Correct answer: (3) Central cell, vital for NEET UG double fertilization.
4. Single Correct Answer MCQ:
Which of the following is generally three in number at chalazal end?
(1) Egg cells
(2) Synergids
(3) Antipodals
(4) Polar nuclei
Explanation: Antipodal cells, located at the chalazal end of the embryo sac, are usually three in number and often degenerate after fertilization. Correct answer: (3) Antipodals, key NEET UG embryology fact.
5. Single Correct Answer MCQ (Clinical-type):
Failure of reduction division in megaspore mother cell leads to:
(1) Triploid embryo sac
(2) Polyploid gametes
(3) Normal embryo sac
(4) Apomictic seed
Explanation: Failure of meiosis produces diploid instead of haploid gametes, potentially leading to polyploidy in offspring. Correct answer: (2) Polyploid gametes, relevant NEET UG clinical embryology.
6. Single Correct Answer MCQ:
Filiform apparatus is present in:
(1) Egg cell
(2) Synergids
(3) Antipodal cells
(4) Central cell
Explanation: Filiform apparatus is a structure in synergids aiding pollen tube guidance. Correct answer: (2) Synergids, important NEET UG fertilization concept.
7. Assertion-Reason MCQ:
Assertion (A): Megaspore mother cell undergoes reduction division.
Reason (R): Meiosis produces four haploid megaspores of which one is functional.
(1) Both A and R are true and R explains A
(2) Both A and R are true but R does not explain A
(3) A is true but R is false
(4) A is false but R is true
Explanation: Both assertion and reason are correct. Meiosis (reduction division) in megaspore mother cell produces four haploid megaspores, with one functional for embryo sac formation. Correct answer: (1) Both A and R are true and R explains A.
8. Matching Type MCQ:
Match the structure with its function:
A. Egg cell
B. Synergid
C. Central cell
D. Antipodals
1. Fuses with male gamete for zygote
2. Guides pollen tube
3. Fuses with male gamete for endosperm
4. Nutritional support or degenerate
Options:
(1) A-1, B-2, C-3, D-4
(2) A-1, B-3, C-2, D-4
(3) A-2, B-1, C-3, D-4
(4) A-3, B-2, C-1, D-4
Explanation: Egg cell forms zygote (A-1), synergid guides pollen tube (B-2), central cell forms endosperm (C-3), antipodals provide nutrition or degenerate (D-4). Correct answer: (1) A-1, B-2, C-3, D-4.
9. Fill in the Blanks MCQ:
The haploid cell that develops into the embryo sac is the ______.
(1) Egg
(2) Functional megaspore
(3) Polar nucleus
(4) Antipodal cell
Explanation: The functional megaspore, resulting from meiosis of megaspore mother cell, develops into the embryo sac containing egg, synergids, polar nuclei, and antipodals. Correct answer: (2) Functional megaspore.
10. Choose the Correct Statements MCQ:
Select correct statements:
(1) Central cell contains two polar nuclei
(2) Egg cell has filiform apparatus
(3) Megaspore mother cell undergoes meiosis
(4) Antipodals are usually three
Options:
(1) 1, 3, 4 only
(2) 1, 2, 3 only
(3) All statements are correct
(4) 2, 3, 4 only
Explanation: Statements 1, 3, and 4 are correct: central cell has two polar nuclei, megaspore mother cell undergoes meiosis, and antipodals are usually three. Egg cell does not have filiform apparatus. Correct answer: (1) 1, 3, 4 only.
Chapter: Reproduction in Plants and Fungi
Topic: Sexual Reproduction and Fungal Structures
Subtopic: Gametogenesis, Flower Morphology, and Fungal Hyphae
Keyword Definitions:
• Syncarpous: Condition where multiple carpels of a flower are fused together.
• Pistillate: Unisexual female flower with functional carpels but no stamens.
• Gametogenesis: Formation of male or female gametes through meiosis.
• Dikaryotic: Hyphal stage in higher fungi containing two nuclei per cell.
• Unisexual Flower: Flower containing either male or female reproductive organs, not both.
Lead Question - 2016 (Phase 2):
Match column – I with column - II and select the correct option using the codes given below:
Column – I | Column – II
(a) Pistils fused together | (i) Gametogenesis
(b) Formation of gametes | (ii) Pistillate
(c) Hyphae of higher Ascomycetes | (iii) Syncarpous
(d) Unisexual female flower | (iv) Dikaryotic
Codes:
(1) a-(iii), b-(i), c-(iv), d-(ii)
(2) a-(iv), b-(iii), c-(i), d-(ii)
(3) a-(ii), b-(i), c-(iv), d-(iii)
(4) a-(i), b-(ii), c-(iv), d-(iii)
Explanation: Correct matching: Pistils fused together = syncarpous (a-iii), formation of gametes = gametogenesis (b-i), hyphae of higher Ascomycetes = dikaryotic (c-iv), unisexual female flower = pistillate (d-ii). Correct answer: (1) a-(iii), b-(i), c-(iv), d-(ii). This highlights floral and fungal reproductive structures, essential for NEET UG.
1. Single Correct Answer MCQ:
Which floral condition has fused carpels?
(1) Apocarpous
(2) Syncarpous
(3) Unisexual
(4) Bisexual
Explanation: Syncarpous flowers have carpels fused together forming a compound pistil. Apocarpous flowers have free carpels. Correct answer: (2) Syncarpous, essential for NEET UG flower morphology.
2. Single Correct Answer MCQ:
The formation of gametes occurs during:
(1) Fertilization
(2) Gametogenesis
(3) Pollination
(4) Zygote formation
Explanation: Gametogenesis is the process of forming male and female gametes via meiosis. Fertilization fuses gametes; pollination transfers pollen. Correct answer: (2) Gametogenesis, crucial for NEET UG reproductive biology.
3. Single Correct Answer MCQ:
Dikaryotic hyphae are found in:
(1) Higher Ascomycetes
(2) Bryophytes
(3) Angiosperms
(4) Gymnosperms
Explanation: Higher Ascomycetes exhibit dikaryotic hyphal stage with two nuclei per cell before karyogamy. Other groups do not show this. Correct answer: (1) Higher Ascomycetes, important for NEET UG mycology.
4. Single Correct Answer MCQ:
A pistillate flower is:
(1) Male only
(2) Female only
(3) Bisexual
(4) Sterile
Explanation: Pistillate flowers are unisexual, containing only functional carpels and lacking stamens. Correct answer: (2) Female only, fundamental for NEET UG flower types.
5. Single Correct Answer MCQ (Clinical-type):
Which process in fungi ensures genetic recombination before karyogamy?
(1) Gametogenesis
(2) Dikaryotic stage
(3) Plasmogamy
(4) Fertilization
Explanation: The dikaryotic stage follows plasmogamy in higher fungi, maintaining two nuclei per hyphal cell before nuclear fusion, facilitating genetic diversity. Correct answer: (2) Dikaryotic stage, relevant for NEET UG fungal reproduction.
6. Single Correct Answer MCQ:
Unisexual female flowers lack:
(1) Carpels
(2) Stamens
(3) Ovules
(4) Sepals
Explanation: Unisexual female (pistillate) flowers lack stamens but contain carpels with ovules. Correct answer: (2) Stamens, key NEET UG concept in angiosperm reproduction.
7. Assertion-Reason MCQ:
Assertion (A): Syncarpous condition leads to compound pistils.
Reason (R): Fusion of carpels forms a single pistil with multiple locules.
(1) Both A and R are true and R is correct explanation of A
(2) Both A and R are true but R is not correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Explanation: Both assertion and reason are true. Fused carpels (syncarpous) form a compound pistil with multiple locules. Correct answer: (1) Both A and R are true and R is correct explanation of A.
8. Matching Type MCQ:
Match the term with description:
A. Syncarpous
B. Pistillate
C. Dikaryotic
D. Gametogenesis
1. Formation of gametes
2. Fusion of carpels
3. Female unisexual flower
4. Two nuclei per hyphal cell
Options:
(1) A-2, B-3, C-4, D-1
(2) A-3, B-2, C-1, D-4
(3) A-2, B-1, C-3, D-4
(4) A-1, B-2, C-3, D-4
Explanation: Syncarpous = fusion of carpels (A-2), pistillate = female unisexual flower (B-3), dikaryotic = two nuclei per hyphal cell (C-4), gametogenesis = formation of gametes (D-1). Correct answer: (1) A-2, B-3, C-4, D-1.
9. Fill in the Blanks MCQ:
Fused carpels forming a compound pistil is called ______.
(1) Apocarpous
(2) Syncarpous
(3) Bisexual
(4) Pistillate
Explanation: Fused carpels forming a single compound pistil is termed syncarpous, whereas apocarpous flowers have free carpels. Correct answer: (2) Syncarpous, key NEET UG flower morphology topic.
10. Choose the Correct Statements MCQ:
Select correct statements:
(1) Dikaryotic hyphae are found in higher fungi
(2) Pistillate flowers contain only carpels
(3) Syncarpous flowers have fused carpels
(4) Gametogenesis forms gametes
Options:
(1) 1, 2, 3 only
(2) 1, 3, 4 only
(3) All statements are correct
(4) 2, 3, 4 only
Explanation: All statements are correct: dikaryotic hyphae exist in higher fungi, pistillate flowers are female only, syncarpous flowers have fused carpels, and gametogenesis forms gametes. Correct answer: (3) All statements are correct.
Topic: Sexual and Asexual Reproduction
Subtopic: Genetic Variation and Mechanisms
Keyword Definitions:
• Sexual Reproduction: Fusion of male and female gametes producing genetically variable offspring.
• Nucellar Polyembryony: Formation of multiple embryos from nucellar tissue, producing clones.
• Vegetative Reproduction: Asexual propagation from vegetative parts, producing genetically identical plants.
• Parthenogenesis: Development of an egg into an organism without fertilization.
• Genetic Variation: Differences in DNA sequences among individuals contributing to evolution and adaptation.
Lead Question - 2016 (Phase 2):
Which one of the following generates new genetic combination leading to variation?
(1) Nucellar polyembryony
(2) Vegetative reproduction
(3) Parthenogenesis
(4) Sexual reproduction
Explanation: Sexual reproduction involves gamete fusion, meiosis, and recombination, generating new genetic combinations, essential for variation in populations. Asexual methods like nucellar polyembryony, vegetative propagation, and parthenogenesis produce clones or identical offspring. Correct answer: (4) Sexual reproduction, fundamental for NEET UG genetics and reproduction.
1. Single Correct Answer MCQ:
Which process contributes to genetic variation in offspring?
(1) Crossing over during meiosis
(2) Binary fission
(3) Budding
(4) Vegetative propagation
Explanation: Crossing over during meiosis exchanges genetic material between homologous chromosomes, producing new combinations and variation. Asexual processes produce identical offspring. Correct answer: (1) Crossing over during meiosis, crucial for NEET UG genetics understanding.
2. Single Correct Answer MCQ:
Parthenogenesis results in
(1) Genetically identical offspring
(2) New genetic recombination
(3) Variation through gamete fusion
(4) Polyploidy only
Explanation: Parthenogenesis produces offspring from unfertilized eggs, often clones of the mother. No genetic recombination occurs. Correct answer: (1) Genetically identical offspring, important NEET UG reproduction topic.
3. Single Correct Answer MCQ:
Nucellar polyembryony is common in
(1) Citrus
(2) Wheat
(3) Maize
(4) Rice
Explanation: In Citrus, nucellar tissue generates multiple embryos alongside the zygotic embryo, producing genetically identical clones. Correct answer: (1) Citrus, relevant for NEET UG asexual reproduction.
4. Single Correct Answer MCQ:
Which of the following is an asexual reproductive method?
(1) Sexual reproduction
(2) Vegetative propagation
(3) Fertilization
(4) Gamete fusion
Explanation: Vegetative propagation is an asexual method producing clones from vegetative parts without gamete fusion. Correct answer: (2) Vegetative propagation, important NEET UG plant reproduction concept.
5. Single Correct Answer MCQ (Clinical-type):
Which method in honeybees leads to male offspring without fertilization?
(1) Sexual reproduction
(2) Parthenogenesis
(3) Vegetative reproduction
(4) Budding
Explanation: Male honeybees (drones) develop from unfertilized eggs via parthenogenesis, producing haploid individuals. Correct answer: (2) Parthenogenesis, vital NEET UG insect reproduction concept.
6. Single Correct Answer MCQ:
Which process ensures combination of maternal and paternal genes?
(1) Nucellar embryony
(2) Sexual reproduction
(3) Budding
(4) Parthenogenesis
Explanation: Sexual reproduction fuses gametes, combining maternal and paternal alleles, creating genetic diversity in offspring. Correct answer: (2) Sexual reproduction, fundamental for NEET UG genetics.
7. Assertion-Reason MCQ:
Assertion (A): Sexual reproduction increases variation in populations.
Reason (R): Meiosis and fertilization produce new gene combinations.
(1) Both A and R are true and R is correct explanation of A
(2) Both A and R are true but R is not correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Explanation: Both assertion and reason are correct. Meiosis and fertilization combine genes from two parents, producing variation in populations. Correct answer: (1) Both A and R are true and R is correct explanation of A.
8. Matching Type MCQ:
Match the reproduction method with genetic outcome:
A. Sexual reproduction
B. Vegetative propagation
C. Nucellar polyembryony
D. Parthenogenesis
1. Produces clones
2. Produces genetic variation
3. Haploid offspring
4. Genetically identical embryos
Options:
(1) A-2, B-1, C-4, D-3
(2) A-2, B-4, C-1, D-3
(3) A-1, B-2, C-4, D-3
(4) A-2, B-1, C-3, D-4
Explanation: Sexual reproduction produces variation, vegetative propagation produces clones, nucellar polyembryony gives identical embryos, parthenogenesis produces haploid offspring. Correct answer: (1) A-2, B-1, C-4, D-3, crucial for NEET UG reproduction understanding.
9. Fill in the Blanks MCQ:
The reproductive method that generates new genetic combinations is ______.
(1) Parthenogenesis
(2) Sexual reproduction
(3) Vegetative propagation
(4) Nucellar polyembryony
Explanation: Sexual reproduction creates new genetic combinations through gamete fusion and meiosis, essential for variation. Correct answer: (2) Sexual reproduction, core NEET UG concept.
10. Choose the Correct Statements MCQ:
Select correct statements:
(1) Asexual reproduction produces clones
(2) Sexual reproduction leads to variation
(3) Parthenogenesis generates identical offspring
(4) Nucellar polyembryony produces clones
Options:
(1) 1, 2, 3 only
(2) 1, 3, 4 only
(3) 2, 3 only
(4) All statements are correct
Explanation: Statements 1, 3, and 4 are correct. Asexual reproduction, parthenogenesis, and nucellar polyembryony produce clones or identical offspring. Sexual reproduction alone generates variation. Correct answer: (2) 1, 3, 4 only.
Topic: Asexual Reproduction and Aquatic Plants
Subtopic: Vegetative Propagation and Environmental Effects
Keyword Definitions:
• Clone: Group of genetically identical individuals produced by asexual reproduction.
• Zoospore: Motile, asexual spore with flagella found in algae and fungi.
• Internode: Stem region between two nodes where leaves and buds arise.
• Asexual Reproduction: Reproduction without gamete fusion, producing genetically identical offspring.
• Vegetative Propagation: Formation of new plants from vegetative parts like stems, leaves, or roots.
Lead Question - 2016 (Phase 2):
Which one of the following statements is not correct?
(1) Water hyacinth, growing in the standing water, drains oxygen from water that leads to the death of fishes
(2) Offspring produced by the asexual reproduction are called clone
(3) Microscopic, motile asexual reproductive structures are called zoospores
(4) In potato, banana and ginger, the plantlets arise from the internodes present in the modified stem
Explanation: Statement 4 is incorrect. In potato, banana, and ginger, the plantlets arise from nodes, not internodes, of modified stems. Water hyacinth reduces oxygen causing fish death, asexual reproduction produces clones, and zoospores are motile asexual structures. Correct answer: (4) In potato, banana and ginger, the plantlets arise from the internodes.
1. Single Correct Answer MCQ:
Which part of potato tuber gives rise to new plants?
(1) Node
(2) Internode
(3) Root tip
(4) Leaf base
Explanation: New potato plants arise from buds located at nodes of the tuber called eyes. Internodes do not directly give rise to new plants. Correct answer: (1) Node, crucial for NEET UG asexual reproduction concepts.
2. Single Correct Answer MCQ:
Zoospores are produced by
(1) Sexual reproduction
(2) Asexual reproduction
(3) Vegetative propagation
(4) Grafting
Explanation: Zoospores are motile, flagellated spores formed asexually in algae and fungi. They do not involve sexual fusion. Correct answer: (2) Asexual reproduction, important for NEET UG plant reproduction questions.
3. Single Correct Answer MCQ:
Clones are produced by
(1) Sexual reproduction
(2) Asexual reproduction
(3) Cross-pollination
(4) Fertilization
Explanation: Asexual reproduction produces genetically identical offspring called clones. Sexual reproduction generates genetic variability. Correct answer: (2) Asexual reproduction, essential NEET UG concept for reproduction.
4. Single Correct Answer MCQ:
Water hyacinth negatively affects aquatic life by
(1) Releasing toxins
(2) Draining oxygen from water
(3) Blocking sunlight only
(4) Consuming fish food
Explanation: Dense growth of water hyacinth reduces dissolved oxygen in water, causing hypoxia and fish death. Other effects are secondary. Correct answer: (2) Draining oxygen from water, relevant for NEET UG environmental plant biology.
5. Single Correct Answer MCQ (Clinical-type):
Which vegetative propagation method is used in ginger?
(1) Rhizome
(2) Bulb
(3) Tuber
(4) Runner
Explanation: Ginger propagates vegetatively via rhizomes, which are horizontal underground stems producing new shoots and roots. Correct answer: (1) Rhizome, essential for NEET UG asexual reproduction studies.
6. Single Correct Answer MCQ:
Banana plantlets develop from
(1) Nodes of rhizome
(2) Nodes of corm
(3) Nodes of stem
(4) Leaf lamina
Explanation: Banana plantlets arise from nodes of underground stem (corm). Growth is vegetative and clonal. Correct answer: (3) Nodes of stem, fundamental for NEET UG vegetative propagation.
7. Assertion-Reason MCQ:
Assertion (A): Asexual reproduction produces genetically identical plants.
Reason (R): No fusion of gametes occurs in asexual reproduction.
(1) Both A and R are true and R is correct explanation of A
(2) Both A and R are true but R is not correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Explanation: Both assertion and reason are correct. Asexual reproduction produces clones because gametes do not fuse, resulting in identical genetic makeup. Correct answer: (1) Both A and R are true and R is correct explanation of A.
8. Matching Type MCQ:
Match plant with its vegetative propagation method:
A. Potato
B. Ginger
C. Banana
D. Onion
1. Bulb
2. Rhizome
3. Node of stem
4. Tuber
Options:
(1) A-4, B-2, C-3, D-1
(2) A-2, B-4, C-3, D-1
(3) A-4, B-3, C-2, D-1
(4) A-1, B-2, C-3, D-4
Explanation: Potato propagates via tuber, ginger via rhizome, banana via stem nodes, and onion via bulb. Correct answer: (1) A-4, B-2, C-3, D-1, essential for NEET UG vegetative propagation.
9. Fill in the Blanks MCQ:
Offspring produced by asexual reproduction are called ______.
(1) Gametes
(2) Clone
(3) Zygote
(4) Seed
Explanation: Asexual reproduction generates genetically identical offspring called clones, without gamete fusion. Correct answer: (2) Clone, fundamental NEET UG reproduction topic.
10. Choose the Correct Statements MCQ:
Select correct statements:
(1) Zoospores are motile asexual spores
(2) Clones arise from sexual reproduction
(3) Vegetative propagation occurs via modified stems
(4) Water hyacinth reduces oxygen in water
Options:
(1) 1, 3, 4 only
(2) 1 and 2 only
(3) 2, 3, 4 only
(4) All statements are correct
Explanation: Statements 1, 3, and 4 are correct. Zoospores are motile asexual spores; vegetative propagation occurs via modified stems; water hyacinth reduces oxygen. Clones are produced asexually, not sexually. Correct answer: (1) 1, 3, 4 only.
Topic: Types of Placentation
Subtopic: Free-central Placentation
Keyword Definitions:
• Placentation: Arrangement of ovules within the ovary of a flower.
• Free-central Placentation: Ovules attached to a central column without septa dividing the ovary.
• Citrus: Genus of flowering trees producing citrus fruits.
• Dianthus: Genus of flowering plants including carnations.
• Argemone: Genus of flowering plants known as prickly poppies.
• Brassica: Genus of plants in the mustard family, including cabbage and mustard.
Lead Question - 2016 (Phase 2):
Free-central placentation is found in
(1) Citrus
(2) Dianthus
(3) Argemone
(4) Brassica
Explanation: Free-central placentation is typically observed in Dianthus, where ovules are attached to a central column without septa in the ovary. This type of arrangement is distinct from others like marginal or axile placentation. The correct answer is (2) Dianthus, as it exhibits free-central placentation commonly studied in botany.
1. Single Correct Answer MCQ:
Which type of placentation is characteristic of Argemone?
(1) Marginal
(2) Axile
(3) Free-central
(4) Parietal
Explanation: Argemone exhibits parietal placentation, where ovules are attached to the inner wall of the ovary. Unlike free-central or axile placentation, parietal placentation lacks a central column, and ovules are positioned along the periphery. Thus, the correct answer is (4) Parietal, important for classifying plant families in botanical studies.
2. Single Correct Answer MCQ:
Which of the following plants shows axile placentation?
(1) Solanum
(2) Dianthus
(3) Argemone
(4) Brassica
Explanation: Axile placentation is seen in Brassica, where ovules are attached to a central axis within a multilocular ovary. This structure contrasts with free-central or parietal types. Therefore, the correct answer is (4) Brassica, commonly referenced in plant reproductive system studies and botany curricula.
3. Single Correct Answer MCQ:
Citrus plants exhibit which type of placentation?
(1) Marginal
(2) Axile
(3) Parietal
(4) Free-central
Explanation: Citrus plants typically display axile placentation, characterized by ovules attached to a central axis in a multilocular ovary. This placentation type supports better nutrient distribution to ovules. Hence, the correct answer is (2) Axile, significant in understanding plant reproductive morphology in botany.
4. Single Correct Answer MCQ:
Which placentation type is seen in Dianthus?
(1) Marginal
(2) Free-central
(3) Parietal
(4) Axile
Explanation: Dianthus displays free-central placentation where ovules attach to a central column without septa. This distinct arrangement differentiates it from parietal and axile types. The correct answer is (2) Free-central, a vital concept in plant reproductive biology essential for NEET UG level preparation.
5. Single Correct Answer MCQ (Clinical-type):
Why is understanding placentation important in clinical botany?
(1) It helps in identifying plant toxins.
(2) It determines fruit development patterns.
(3) It aids in recognizing allergenic plants.
(4) It helps in medicinal plant identification.
Explanation: Understanding placentation helps in medicinal plant identification by providing morphological features critical for classification and correct identification. This knowledge is crucial for avoiding misidentification of toxic plants used in traditional medicine. The correct answer is (4) It helps in medicinal plant identification, relevant for pharmacognosy and clinical botany.
6. Single Correct Answer MCQ:
Which characteristic is true of free-central placentation?
(1) Ovules attached to ovary wall
(2) Ovules attached to a central column without septa
(3) Ovules arranged in separate locules
(4) Ovules attached to the base of the ovary
Explanation: Free-central placentation features ovules attached to a central column without septa, differing from marginal or axile types. This morphological trait is important in plant systematics and identification. The correct answer is (2) Ovules attached to a central column without septa, frequently examined in botany exams.
7. Assertion-Reason MCQ:
Assertion (A): Dianthus exhibits free-central placentation.
Reason (R): Ovules are attached to a central column without septa.
(1) Both A and R are true and R is correct explanation of A
(2) Both A and R are true but R is not correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Explanation: The assertion is correct, and the reason is also correct and directly explains the assertion. In Dianthus, free-central placentation occurs where ovules attach to a central column without septa. Thus, the correct answer is (1) Both A and R are true and R is correct explanation of A.
8. Matching Type MCQ:
Match the plant with its type of placentation:
A. Argemone
B. Brassica
C. Citrus
D. Dianthus
1. Axile
2. Parietal
3. Free-central
4. Axile
Options:
(1) A-2, B-1, C-4, D-3
(2) A-3, B-2, C-1, D-4
(3) A-1, B-2, C-3, D-4
(4) A-2, B-3, C-1, D-4
Explanation: Correct matching is A-2 (Argemone-Parietal), B-1 (Brassica-Axile), C-4 (Citrus-Axile), D-3 (Dianthus-Free-central). Understanding these associations is key for NEET UG exam preparation as they help in plant classification. Thus, the correct answer is (1) A-2, B-1, C-4, D-3.
9. Fill in the Blanks MCQ:
In free-central placentation, ovules are attached to a ______ column without septa.
(1) lateral
(2) central
(3) basal
(4) peripheral
Explanation: In free-central placentation, ovules are attached to a central column without septa. This distinct structural feature differentiates it from other types of placentation like parietal or axile. The correct answer is (2) central, essential for understanding plant reproductive anatomy in NEET UG studies.
10. Choose the Correct Statements MCQ:
Select the correct statements regarding free-central placentation:
(1) Ovules are attached to a central column
(2) Septa are present
(3) Found in Dianthus
(4) Common in Citrus
Options:
(1) 1 and 3 only
(2) 2 and 4 only
(3) 1, 2, and 3
(4) 3 and 4 only
Explanation: Free-central placentation features ovules attached to a central column without septa and is found in Dianthus. Citrus exhibits axile placentation. Thus, the correct answer is (1) 1 and 3 only, fundamental for NEET UG botany section preparation.
Subtopic: Floral Symmetry
Keyword Definitions:
• Radial Symmetry: Symmetry where flower parts are arranged around a central axis, allowing multiple planes of symmetry.
• Cassia: Genus of flowering plants in Fabaceae family, used for medicinal and ornamental purposes.
• Brassica: Genus of plants including mustard, cabbage, and cauliflower, important in agriculture.
• Trifolium: Genus of clover plants, important for nitrogen fixation.
• Pisum: Genus of legumes including pea plants, important in food and agriculture.
Lead Question - 2016 (Phase 2):
Radial symmetry is found in the flowers of
(1) Cassia
(2) Brassica
(3) Trifolium
(4) Pisum
Explanation: The correct answer is (2) Brassica. Brassica flowers exhibit radial symmetry, where floral parts are arranged evenly around the center, allowing any plane passing through the axis to divide the flower into equal halves. This is typical of many angiosperms, promoting accessibility to various pollinators.
1. Single Correct Answer MCQ:
What type of symmetry does a typical pea (Pisum) flower exhibit?
(1) Radial symmetry
(2) Bilateral symmetry
(3) Asymmetry
(4) Spiral symmetry
Explanation: The correct answer is (2) Bilateral symmetry. Pisum flowers display bilateral symmetry, having a single plane that divides the flower into two mirror-image halves, aiding specialized pollination mechanisms.
2. Single Correct Answer MCQ:
Which feature is characteristic of radially symmetrical flowers?
(1) Specialized pollinators
(2) Multiple planes of symmetry
(3) Irregular shape
(4) Only one plane of symmetry
Explanation: The correct answer is (2) Multiple planes of symmetry. Radial symmetry allows flowers like Brassica to be accessible from any direction, favoring generalized pollination.
3. Single Correct Answer MCQ:
Which of these plants commonly shows bilateral symmetry in flowers?
(1) Brassica
(2) Cassia
(3) Trifolium
(4) All of the above
Explanation: The correct answer is (2) Cassia. Cassia flowers are bilaterally symmetrical, adapted to specialized pollinators by presenting a defined landing platform and directing pollen transfer efficiently.
4. Single Correct Answer MCQ:
Radial symmetry in flowers helps in
(1) Specialized pollination
(2) Wind dispersal
(3) Attracting various pollinators
(4) Seed development
Explanation: The correct answer is (3) Attracting various pollinators. Radially symmetrical flowers, such as Brassica, are accessible from multiple directions, allowing a wide range of pollinators to visit and aid reproduction.
5. Single Correct Answer MCQ (Clinical Type):
Why is understanding flower symmetry important in agriculture?
(1) It helps in disease diagnosis
(2) Guides breeding for effective pollination
(3) Improves herbicide resistance
(4) Determines soil type
Explanation: The correct answer is (2) Guides breeding for effective pollination. Knowledge of flower symmetry helps in selecting compatible plants and optimizing pollination, boosting yield in crops like Brassica.
6. Single Correct Answer MCQ:
Which plant family typically exhibits radial symmetry in flowers?
(1) Fabaceae
(2) Brassicaceae
(3) Poaceae
(4) Asteraceae
Explanation: The correct answer is (2) Brassicaceae. Plants like Brassica from the Brassicaceae family commonly display radial symmetry, aiding pollinator access and reproduction.
7. Assertion-Reason MCQ:
Assertion (A): Radial symmetry allows flowers to be accessed by a wide variety of pollinators.
Reason (R): Multiple planes of symmetry facilitate pollinator visits from any direction.
(1) Both A and R are true, and R is the correct explanation of A.
(2) Both A and R are true, but R is not the correct explanation of A.
(3) A is true, but R is false.
(4) Both A and R are false.
Explanation: The correct answer is (1) Both A and R are true, and R is the correct explanation of A. Radial symmetry permits equal access for different pollinators, enhancing reproductive success.
8. Matching Type MCQ:
Match the plant to its flower symmetry:
A. Brassica
B. Cassia
C. Trifolium
D. Pisum
1. Radial symmetry
2. Bilateral symmetry
(1) A-1, B-2, C-2, D-2
(2) A-2, B-1, C-1, D-2
(3) A-1, B-1, C-2, D-1
(4) A-2, B-2, C-1, D-1
Explanation: The correct answer is (1) A-1, B-2, C-2, D-2. Brassica has radial symmetry; Cassia, Trifolium, and Pisum show bilateral symmetry.
9. Fill in the Blanks MCQ:
Brassica flowers are characterized by ______ symmetry.
(1) Bilateral
(2) Asymmetrical
(3) Radial
(4) Spiral
Explanation: The correct answer is (3) Radial. Radial symmetry allows equal accessibility from multiple directions, aiding pollination by various agents.
10. Choose the correct statements MCQ:
Select correct statements regarding flower symmetry:
(1) Radial symmetry promotes cross-pollination.
(2) Bilateral symmetry restricts pollinator type.
(3) All Fabaceae plants show radial symmetry.
(4) Brassica flowers are radially symmetrical.
(1) 1, 2, and 4 only
(2) 1 and 3 only
(3) 2 and 3 only
(4) All of the above
Explanation: The correct answer is (1) 1, 2, and 4 only. Radial symmetry aids diverse pollination; bilateral restricts pollinators. Fabaceae like Pisum and Cassia are bilaterally symmetrical; Brassica is radially symmetrical.
Subtopic: Floral Structures and Adaptations
Keyword Definitions:
• Stamens: Male reproductive parts of a flower, consisting of anther and filament.
• Indigofera: A genus of flowering plants known for nitrogen fixation and dye production.
• Sesbania: A genus of leguminous plants, often used as green manure.
• Salvia: A genus of plants in the mint family, known for aromatic properties.
• Allium: Genus including onions, garlic; characterized by bulbous plants.
• Aloe: A genus of succulent plants used for medicinal purposes.
• Mustard: Plants known for producing seeds rich in oil and spice.
• Groundnut: Also called peanut, a legume with underground seed development.
• Radish: Root vegetable with pungent taste, used in salads.
• Gram: Cicer arietinum, a leguminous crop used as a pulse.
• Turnip: Root vegetable cultivated for edible tuber.
Lead Question - 2016 (Phase 2):
How many plants among Indigofera, Sesbania, Salvia, Allium, Aloe, Mustard, Groundnut, Radish, Gram, and Turnip have stamens with different lengths in their flowers?
(1) Six
(2) Three
(3) Four
(4) Five
Explanation: The correct answer is (1) Six. Indigofera, Sesbania, Salvia, Allium, Mustard, and Gram exhibit stamens of unequal lengths, aiding in cross-pollination by promoting efficient pollen transfer and reducing self-pollination, a key evolutionary trait in many angiosperms for genetic diversity.
1. Single Correct Answer MCQ:
What is the primary function of stamens in a flower?
(1) Protect ovules
(2) Produce pollen
(3) Attract pollinators
(4) Store nutrients
Explanation: The correct answer is (2) Produce pollen. Stamens consist of filament and anther where pollen, containing male gametes, is produced. Pollen is essential for sexual reproduction in plants.
2. Single Correct Answer MCQ:
Which plant is known for its unequal length stamens?
(1) Aloe
(2) Salvia
(3) Turnip
(4) Radish
Explanation: The correct answer is (2) Salvia. Salvia exhibits unequal stamens which facilitate precise pollen placement on pollinators, enhancing cross-pollination and reducing self-pollination.
3. Single Correct Answer MCQ:
Why do some plants have stamens of unequal length?
(1) Reduce attraction of pollinators
(2) Promote self-pollination
(3) Facilitate cross-pollination
(4) Enhance photosynthesis
Explanation: The correct answer is (3) Facilitate cross-pollination. Unequal stamen lengths ensure pollen from anther contacts pollinators at specific positions, improving cross-pollination efficiency and genetic diversity.
4. Single Correct Answer MCQ:
Which of these plants typically have equal length stamens?
(1) Indigofera
(2) Mustard
(3) Aloe
(4) Sesbania
Explanation: The correct answer is (3) Aloe. Aloe’s flowers generally possess stamens of equal length, suited to their specific pollination mechanisms involving insects.
5. Single Correct Answer MCQ (Clinical Type):
How does understanding floral stamen variation assist in agriculture?
(1) Ensures uniform seed production
(2) Helps develop pest-resistant crops
(3) Guides breeding for cross-pollination traits
(4) Increases water absorption
Explanation: The correct answer is (3) Guides breeding for cross-pollination traits. Knowledge of stamen morphology assists in selecting plants for hybridization programs, improving yield and genetic diversity in crops.
6. Single Correct Answer MCQ:
Which plant is a leguminous crop with unequal stamens?
(1) Gram
(2) Allium
(3) Aloe
(4) Turnip
Explanation: The correct answer is (1) Gram. Gram (Cicer arietinum) shows stamens of unequal lengths, promoting cross-pollination and enhancing reproductive success.
7. Assertion-Reason MCQ:
Assertion (A): Unequal stamen length promotes genetic diversity.
Reason (R): It facilitates cross-pollination and reduces self-pollination.
(1) Both A and R are true, and R is correct explanation of A.
(2) Both A and R are true, but R is not correct explanation of A.
(3) A is true, but R is false.
(4) Both A and R are false.
Explanation: The correct answer is (1) Both A and R are true, and R is correct explanation of A. Different stamen lengths help avoid self-pollination, promoting cross-pollination and genetic variation.
8. Matching Type MCQ:
Match the plant to its stamen characteristic:
A. Salvia
B. Mustard
C. Aloe
D. Indigofera
1. Unequal stamens
2. Equal stamens
(1) A-1, B-1, C-2, D-1
(2) A-2, B-1, C-1, D-1
(3) A-1, B-2, C-2, D-1
(4) A-1, B-1, C-1, D-2
Explanation: The correct answer is (1) A-1, B-1, C-2, D-1. Salvia, Mustard, and Indigofera show unequal stamens, whereas Aloe has equal stamens.
9. Fill in the Blanks MCQ:
The term ‘polyadelphous’ refers to stamens united by their ______.
(1) Anthers
(2) Filaments
(3) Ovules
(4) Petals
Explanation: The correct answer is (2) Filaments. Polyadelphous condition indicates stamens united by their filaments into multiple bundles, aiding in structural support and effective pollen transfer.
10. Choose the correct statements MCQ:
Select correct statements regarding plant reproductive structures:
(1) Stamens produce pollen.
(2) Gynoecium contains anthers.
(3) Polyadelphous condition involves multiple stamen bundles.
(4) Unequal stamen lengths aid cross-pollination.
(1) 1, 3, and 4 only
(2) 2 and 3 only
(3) 1 and 2 only
(4) All of the above
Explanation: The correct answer is (1) 1, 3, and 4 only. Stamens produce pollen, polyadelphous refers to multiple bundles, and unequal stamen lengths promote cross-pollination. Gynoecium contains carpels, not anthers.
Subtopic: Flower Structure and Types
Keyword Definitions:
• Polyadelphous: Condition where stamens are united by their filaments into multiple bundles.
• Calyx: The outermost whorl of a flower, composed of sepals.
• Gynoecium: The female reproductive part of a flower, consisting of one or more carpels.
• Androecium: The male reproductive part of a flower, made up of stamens.
• Corolla: The second whorl of the flower, formed by petals.
Lead Question - 2016 (Phase 2):
The term ‘polyadelphous’ is related to
(1) Calyx
(2) Gynoecium
(3) Androecium
(4) Corolla
Explanation: The correct answer is (3) Androecium. Polyadelphous refers to the condition where stamens (male parts) are united by their filaments into several groups or bundles. This is a common trait in some plant families, aiding in structural support and efficient pollen dispersal.
1. Single Correct Answer MCQ:
What is the function of the androecium in a flower?
(1) Protect ovules
(2) Produce pollen
(3) Attract pollinators
(4) Support petals
Explanation: The correct answer is (2) Produce pollen. The androecium consists of stamens, each having a filament and anther where pollen is produced. Pollen contains male gametes necessary for fertilization.
2. Single Correct Answer MCQ:
Which floral part collectively forms the male reproductive structure?
(1) Gynoecium
(2) Androecium
(3) Calyx
(4) Corolla
Explanation: The correct answer is (2) Androecium. The androecium is composed of stamens that produce pollen, thus constituting the male reproductive part of a flower.
3. Single Correct Answer MCQ:
Polyadelphous condition is commonly observed in which family?
(1) Fabaceae
(2) Solanaceae
(3) Liliaceae
(4) Poaceae
Explanation: The correct answer is (1) Fabaceae. In Fabaceae (legume family), stamens are often polyadelphous, with their filaments united into several bundles, promoting efficient pollen transfer during pollination.
4. Single Correct Answer MCQ:
Which plant part is composed of sepals?
(1) Corolla
(2) Calyx
(3) Androecium
(4) Gynoecium
Explanation: The correct answer is (2) Calyx. The calyx is the outermost floral whorl, made up of sepals that protect the developing flower bud.
5. Single Correct Answer MCQ (Clinical Type):
Polyadelphous stamens in a plant are advantageous because they:
(1) Prevent insect pollination
(2) Facilitate wind dispersal of pollen
(3) Provide structural strength and effective pollen transfer
(4) Inhibit self-pollination
Explanation: The correct answer is (3) Provide structural strength and effective pollen transfer. Polyadelphous stamens, grouped into bundles, ensure stability and efficient delivery of pollen to pollinators, enhancing reproductive success.
6. Single Correct Answer MCQ:
Which term describes united stamens into a single bundle?
(1) Polyadelphous
(2) Monadelphous
(3) Diadelphous
(4) Syngenesious
Explanation: The correct answer is (2) Monadelphous. In monadelphous condition, all stamens are united by their filaments into a single bundle, differing from polyadelphous where they form multiple bundles.
7. Assertion-Reason MCQ:
Assertion (A): Polyadelphous condition is observed in flowers of family Fabaceae.
Reason (R): Stamens are united into several bundles to improve pollination efficiency.
(1) Both A and R are true, and R is correct explanation of A.
(2) Both A and R are true, but R is not correct explanation of A.
(3) A is true, but R is false.
(4) Both A and R are false.
Explanation: The correct answer is (1) Both A and R are true, and R is correct explanation of A. In Fabaceae, polyadelphous stamens promote stability and efficient pollen delivery by grouping filaments into multiple bundles.
8. Matching Type MCQ:
Match the floral term to its description:
A. Calyx
B. Gynoecium
C. Androecium
D. Corolla
1. Male reproductive part
2. Female reproductive part
3. Petal whorl
4. Sepal whorl
(1) A-4, B-2, C-1, D-3
(2) A-1, B-3, C-4, D-2
(3) A-3, B-1, C-2, D-4
(4) A-2, B-4, C-1, D-3
Explanation: The correct answer is (1) A-4, B-2, C-1, D-3. Calyx is sepals, Gynoecium is female reproductive organ, Androecium is male reproductive organ, and Corolla is petal whorl.
9. Fill in the Blanks MCQ:
Polyadelphous condition refers to stamens united by their ______.
(1) Anthers
(2) Filaments
(3) Ovules
(4) Sepals
Explanation: The correct answer is (2) Filaments. In the polyadelphous condition, stamens are united by their filaments into multiple bundles, aiding structural integrity and effective pollen transfer.
10. Choose the correct statements MCQ:
Select correct statements about flower structure:
(1) Androecium consists of stamens.
(2) Gynoecium produces pollen.
(3) Polyadelphous condition involves multiple stamen bundles.
(4) Calyx is made of petals.
(1) 1 and 3 only
(2) 2 and 4 only
(3) 1, 3, and 4 only
(4) All of the above
Explanation: The correct answer is (1) 1 and 3 only. Androecium consists of stamens and polyadelphous condition refers to multiple stamen bundles. Gynoecium is female part producing ovules, and calyx consists of sepals, not petals.
Chapter: Sexual Reproduction in Flowering Plants
Topic: Post-fertilisation Structures and Events
Subtopic: Endosperm Development
Keywords:
Coconut water – The free nuclear liquid endosperm of a tender coconut.
Endosperm – Nutritive tissue formed after double fertilisation, nourishing the developing embryo.
Free nuclear endosperm – Type of endosperm where repeated nuclear divisions occur without cell wall formation.
Proembryo – Early stage of embryo before differentiation.
Embryo sac – Female gametophyte in angiosperms where fertilisation occurs.
Mesocarp – Middle fleshy layer of fruit wall.
Endocarp – Innermost hard layer of fruit wall.
Double fertilisation – Unique feature of angiosperms where one male gamete fuses with egg and the other with polar nuclei.
Nuclear divisions – Process of multiplication of nuclei without cytokinesis, seen in free nuclear endosperm.
Clinical relevance – Endosperm is a major source of nutrition in cereals consumed by humans.
Lead Question – 2016 (Phase 1)
The coconut water from tender coconut represents:
(1) Endocarp
(2) Fleshy mesocarp
(3) Free nuclear proembryo
(4) Free nuclear endosperm
Explanation: Coconut water is the free nuclear endosperm formed after fertilisation by the fusion of a male gamete with polar nuclei. It remains multinucleate and provides nutrition to the developing embryo. The coconut’s white kernel is the cellular endosperm. Answer: (4) Free nuclear endosperm.
Question 2. The white kernel (flesh) of coconut represents:
(1) Free nuclear proembryo
(2) Cellular endosperm
(3) Fleshy mesocarp
(4) Embryo
Explanation: The edible white kernel of coconut is the cellular endosperm, formed when free nuclear endosperm undergoes cytokinesis. It stores food for the developing embryo. Answer: (2) Cellular endosperm.
Question 3. Which type of endosperm development occurs in coconut?
(1) Nuclear
(2) Cellular
(3) Helobial
(4) None of the above
Explanation: Coconut shows nuclear type of endosperm development where free nuclear divisions occur initially, and later cell wall formation produces cellular endosperm (white kernel). Answer: (1) Nuclear.
Question 4. Assertion (A): Coconut water is free nuclear endosperm.
Reason (R): It results from fusion of male gamete with secondary nucleus during double fertilisation.
(1) Both A and R are true and R is the correct explanation of A
(2) Both A and R are true but R is not the correct explanation
(3) A is true but R is false
(4) A is false but R is true
Explanation: The second fertilisation event fuses a male gamete with two polar nuclei, forming primary endosperm nucleus, which undergoes nuclear divisions to form coconut water. Thus, A and R are true and R correctly explains A. Answer: (1).
Question 5. Match the following:
A. Coconut water → (i) Free nuclear endosperm
B. Coconut flesh → (ii) Cellular endosperm
C. Endocarp → (iii) Hard shell
D. Mesocarp → (iv) Fibrous husk
(1) A-i, B-ii, C-iii, D-iv
(2) A-ii, B-i, C-iv, D-iii
(3) A-iii, B-iv, C-i, D-ii
(4) A-iv, B-iii, C-ii, D-i
Explanation: Coconut water is free nuclear endosperm, white flesh is cellular endosperm, endocarp forms the hard shell, and mesocarp is the fibrous husk. Answer: (1).
Question 6. The nutritive tissue for developing embryo in angiosperms is:
(1) Endosperm
(2) Perisperm
(3) Mesocarp
(4) Cotyledon
Explanation: Endosperm is the unique nutritive tissue of angiosperms formed by triple fusion during double fertilisation. It provides nutrition to the developing embryo and may persist or get absorbed. Answer: (1) Endosperm.
Question 7. Fill in the blank: The fusion of one male gamete with two polar nuclei forms ________.
(1) Primary endosperm nucleus
(2) Secondary nucleus
(3) Syngamy
(4) Zygote
Explanation: The fusion of a male gamete with two polar nuclei inside the central cell produces the triploid primary endosperm nucleus, which develops into endosperm. Answer: (1) Primary endosperm nucleus.
Question 8. A farmer observed that in cereals like rice and wheat, the seed is rich in starchy endosperm. This tissue is homologous to which part in coconut?
(1) Endocarp
(2) Free nuclear endosperm
(3) Mesocarp
(4) Cotyledon
Explanation: Starchy endosperm in cereals is homologous to coconut endosperm. In tender coconut, it is free nuclear (liquid) and later forms the white kernel (cellular). Answer: (2) Free nuclear endosperm.
Question 9. Passage-based MCQ:
"In flowering plants, double fertilisation produces both zygote and primary endosperm nucleus. The primary endosperm nucleus undergoes divisions forming free nuclear endosperm. In coconut, this is represented by liquid endosperm (coconut water), which nourishes the embryo until maturity."
Which statement is correct?
(1) Coconut water is mesocarp
(2) Coconut water is free nuclear endosperm
(3) Coconut flesh is free nuclear endosperm
(4) Coconut water is zygote
Explanation: Coconut water is the liquid free nuclear endosperm formed by nuclear divisions without cytokinesis. Coconut flesh is the cellular endosperm. Answer: (2) Coconut water is free nuclear endosperm.
Question 10. In clinical nutrition, why are cereals like rice and maize considered staple foods?
(1) They are rich in endosperm providing carbohydrates
(2) They are rich in proteins from embryo
(3) They are rich in vitamins from pericarp
(4) They contain high water content like coconut
Explanation: Cereals provide staple diet because their seeds contain large amounts of starchy endosperm that supply carbohydrates as the main energy source. This is comparable to nutritive role of endosperm in coconut. Answer: (1) They are rich in endosperm providing carbohydrates.
Chapter: Plant Physiology
Topic: Reproduction in Flowering Plants
Subtopic: Pollination and Fertilization
Keyword Definitions:
Pollen Grain: Male gametophyte of seed plants involved in sexual reproduction.
Stigma: Part of pistil where pollen lands and germinates.
Pollen Tube: A tube that grows from pollen grain through style to ovule for fertilization.
Pistil: Female reproductive organ of a flower, including stigma, style, and ovary.
Pollinators: Organisms that transfer pollen from male to female floral parts aiding fertilization.
Pollen/Nectar Robbers: Insects that consume resources without aiding pollination.
Reptilian Pollination: Pollination involving reptiles as pollinators in rare plant species.
2016 (Phase 1)
Lead Question: Which of the following statements is not correct :
(1) Pollen grains of many species can germinate on the stigma of a flower, but only one pollen tube of the same species grows into the style
(2) Insects that consume pollen or nectar without bringing about pollination are called pollen/nectar robbers.
(3) Pollen germination and pollen tube growth are regulated by chemical components pollen interacting with those of the pistil.
(4) Some reptiles have also been reported as pollinators in some plant species
Answer & Explanation: The correct answer is (1). The statement is incorrect because many pollen tubes from different pollen grains can grow into the style, but generally only one successfully fertilizes the ovule. The other pollen tubes degenerate. This ensures genetic diversity while preventing polyspermy in flowering plants.
Single Correct Answer MCQ: The main role of the pollen tube in plant reproduction is to:
(1) Transport sperm cells to ovule
(2) Produce gametes
(3) Generate energy for pollen
(4) Absorb nutrients from the style
Answer & Explanation: The correct answer is (1). The pollen tube grows from the stigma through the style and carries sperm cells to the ovule for fertilization. This structure is crucial in sexual reproduction, allowing sperm cells to reach and fertilize the egg cell within the ovule.
Assertion-Reason MCQ:
Assertion (A): Pollen germination depends on chemical signaling between pollen and pistil.
Reason (R): Specific interactions ensure compatibility and successful fertilization.
(1) Both A and R are true, and R is correct explanation of A.
(2) Both A and R are true, but R is not correct explanation of A.
(3) A is true, but R is false.
(4) A is false, but R is true.
Answer & Explanation: The correct answer is (1). Chemical interactions between the pollen and pistil ensure species-specific compatibility, preventing cross-species fertilization. These molecular signals facilitate recognition and successful pollen tube growth, enabling efficient fertilization.
Matching Type MCQ: Match the Term to its Description:
A. Pollinators 1. Organisms aiding pollen transfer
B. Nectar Robbers 2. Consume nectar without pollinating
C. Pollen Tube 3. Structure transporting sperm cells
D. Pollen Grain 4. Male gametophyte of seed plants
(1) A-1, B-2, C-3, D-4
(2) A-2, B-1, C-4, D-3
(3) A-1, B-3, C-2, D-4
(4) A-4, B-1, C-3, D-2
Answer & Explanation: The correct answer is (1). Pollinators aid pollen transfer; nectar robbers consume nectar without aiding pollination; pollen tube transports sperm cells to ovule; pollen grain is the male gametophyte essential for sexual reproduction in plants.
Fill in the Blanks / Completion MCQ: The process where specific pollen and pistil chemical interaction occurs is called ________.
(1) Pollination
(2) Fertilization
(3) Compatibility Reaction
(4) Transpiration
Answer & Explanation: The correct answer is (3). Compatibility reaction involves molecular communication between pollen and pistil determining whether pollen germination and tube growth proceed, ensuring species-specific fertilization and preventing cross-species fertilization.
Choose the correct statements MCQ:
1. Only one pollen tube usually fertilizes the ovule.
2. Pollen/nectar robbers help in cross-pollination.
3. Chemical components regulate pollen germination.
4. Reptiles can act as pollinators in some cases.
(1) 1, 3, and 4 only
(2) 1 and 2 only
(3) 2 and 3 only
(4) 1, 2, and 4 only
Answer & Explanation: The correct answer is (1). Only one pollen tube successfully fertilizes the ovule while others degenerate. Chemical interactions regulate pollen germination, and reptiles are occasional pollinators. However, nectar robbers do not contribute to pollination and are detrimental to the process.
Topic: Seed Structure and Germination
Subtopic: Monocot Seed Anatomy
Keyword Definitions:
Cotyledon: Part of the seed that stores food and supports seedling growth.
Plumule: Embryonic shoot present in seed that develops into the plant shoot system.
Coleorhiza: Protective sheath covering the radicle in monocot seeds during germination.
Coleoptile: Protective sheath covering the young shoot in monocot seeds during germination.
Scutellum: Specialized cotyledon in monocots like maize, acting as an absorptive organ.
2016 (Phase 1)
Lead Question: Cotyledon of maize grain is called:
(1) Plumule
(2) Coleorhiza
(3) Coleoptile
(4) Scutellum
Answer & Explanation: The correct answer is (4). In maize, a monocot plant, the single cotyledon is known as the scutellum. It serves as a specialized organ to absorb nutrients from the endosperm and deliver them to the developing embryo, enabling proper germination and seedling growth.
Keyword Definitions:
Endosperm: Tissue providing stored food for the developing embryo in seeds.
Single Correct Answer MCQ: The primary function of the scutellum in maize is to:
(1) Protect the radicle
(2) Absorb nutrients from endosperm
(3) Develop into first leaves
(4) Store water
Answer & Explanation: The correct answer is (2). The scutellum absorbs nutrients from the endosperm and transfers them to the embryo during germination. This ensures the seedling develops properly before its own photosynthesis begins, which is crucial for establishing healthy plant growth in agricultural settings.
Keyword Definitions:
Embryo: Young plant within a seed destined to develop into a mature plant.
Single Correct Answer MCQ (Clinical Type): Deficiency of nutrients absorbed by the scutellum may result in:
(1) Normal seedling growth
(2) Delayed or impaired germination
(3) Enhanced photosynthesis
(4) Increased disease resistance
Answer & Explanation: The correct answer is (2). A scutellum that fails to efficiently absorb nutrients leads to poor seedling vigor or complete failure to germinate. This is critical in agriculture, as unhealthy seedlings reduce crop yield and affect food production, necessitating proper seed treatment practices.
Keyword Definitions:
Seedling: Young plant developed from a seed post germination.
Single Correct Answer MCQ: Which structure protects the plumule in monocot seeds?
(1) Coleorhiza
(2) Scutellum
(3) Coleoptile
(4) Endosperm
Answer & Explanation: The correct answer is (3). The coleoptile is a specialized sheath that protects the plumule during germination. It allows the young shoot to safely pass through the soil, preventing mechanical damage and ensuring proper growth into the plant’s above-ground shoot system.
Keyword Definitions:
Coleoptile: Sheath protecting the emerging shoot in monocot seeds during germination.
Single Correct Answer MCQ: In maize, the number of cotyledons is:
(1) Two
(2) One
(3) Three
(4) None
Answer & Explanation: The correct answer is (2). Maize is a monocotyledonous plant, possessing a single cotyledon called the scutellum. This contrasts with dicot plants, which have two cotyledons. The scutellum plays an essential role during germination by absorbing and transferring nutrients from the endosperm to the growing embryo.
Keyword Definitions:
Monocotyledon: Plant class with a single cotyledon in the seed structure.
Assertion-Reason MCQ:
Assertion (A): The scutellum is a specialized cotyledon in monocots.
Reason (R): The scutellum absorbs food from endosperm to nourish the embryo.
(1) Both A and R are true, and R is the correct explanation of A
(2) Both A and R are true, but R is not correct explanation of A
(3) A is true, but R is false
(4) A is false, but R is true
Answer & Explanation: The correct answer is (1). The scutellum functions as a specialized cotyledon by absorbing nutrients from the endosperm and delivering them to the embryo during germination. This ensures proper development of the young plant, making the assertion and reason both correct and interdependent.
Keyword Definitions:
Embryo Nourishment: Process supplying essential nutrients for early growth from stored food.
Matching Type MCQ: Match the part with its function:
A. Scutellum 1. Absorbs food from endosperm
B. Coleoptile 2. Protects plumule during germination
C. Coleorhiza 3. Protects radicle during germination
(1) A-1, B-2, C-3
(2) A-2, B-1, C-3
(3) A-3, B-2, C-1
(4) A-1, B-3, C-2
Answer & Explanation: The correct answer is (1). The scutellum absorbs nutrients from the endosperm, coleoptile protects the plumule, and coleorhiza protects the radicle during germination. These structural adaptations in maize ensure successful early development of the seedling and prevent damage to sensitive tissues.
Keyword Definitions:
Coleorhiza: Sheath protecting the radicle during germination in monocots.
Fill in the Blanks / Completion MCQ: The scutellum of maize primarily functions to __________.
(1) store water
(2) absorb nutrients from endosperm
(3) protect the embryo
(4) develop into leaves
Answer & Explanation: The correct answer is (2). The scutellum absorbs nutrients from the endosperm and passes them to the embryo during germination. This transfer is vital for the seedling’s initial growth phase before it becomes photosynthetically active and independently sustains its development.
Keyword Definitions:
Endosperm: Nutrient-rich tissue supplying energy to the growing embryo.
Choose the correct statements MCQ:
1. Scutellum acts as nutrient absorber in maize.
2. Coleoptile protects radicle during germination.
3. Maize is a monocotyledonous plant.
4. Plumule becomes the shoot system.
(1) 1, 3, 4 only
(2) 1 and 2 only
(3) 1, 2, 3 only
(4) All statements are correct
Answer & Explanation: The correct answer is (1). Scutellum absorbs nutrients; coleoptile protects the plumule (not radicle). Maize is a monocot, and the plumule develops into the shoot system. Understanding these facts is essential in botany and agricultural science for correct seed classification and germination practices.
Chapter: Plant Reproduction
Topic: Microsporogenesis and Pollen Biology
Subtopic: Pollen Structure, Function, and Applications
Keyword Definitions:
Tapetum: Nutritive tissue in the anther providing enzymes and materials for pollen development.
Exine: Outer wall of pollen grains composed of sporopollenin, resistant to degradation.
Sporopollenin: Durable biopolymer forming the exine, providing protection to pollen.
Pollen Allergy: Immune reaction caused by pollen proteins in sensitive individuals.
Cryopreservation: Storage of biological material at very low temperatures for future use.
2016 (Phase 1)
Lead Question: Which one of the following statements is not true:
(1) Tapetum helps in the dehiscence of anther
(2) Exine of pollen grains is made up of sporopollenin
(3) Pollen grains of many species cause severe allergies
(4) Stored pollen in liquid nitrogen can be used in crop breeding programmes
Answer & Explanation: The correct answer is (1). Tapetum does not directly help in anther dehiscence; its main role is to provide nutrition and materials for pollen development. Exine is composed of sporopollenin, pollen can cause allergies, and cryopreserved pollen is useful in crop breeding, making option (1) incorrect.
Keyword Definitions:
Anther: Male reproductive organ producing pollen in flowering plants.
Pollen Grain: Male gametophyte that fertilizes ovules in plants.
2020
Single Correct Answer MCQ: What is the primary function of the tapetum?
(1) Anther dehiscence
(2) Pollen nourishment
(3) Fertilization of ovule
(4) Pollen dispersal
Answer & Explanation: The correct answer is (2). Tapetum provides nutrients, enzymes, and materials like sporopollenin precursors for proper development of pollen grains. It is essential for microspore maturation but does not directly aid in anther dehiscence or pollen dispersal.
Keyword Definitions:
Pollen Wall: Multi-layered structure with exine and intine protecting male gametophytes.
2019
Single Correct Answer MCQ: Exine of pollen is resistant because it contains:
(1) Cellulose
(2) Sporopollenin
(3) Lignin
(4) Pectin
Answer & Explanation: The correct answer is (2). Exine is made of sporopollenin, a highly durable and chemically inert biopolymer. This provides mechanical strength and protection against UV radiation, desiccation, and microbial attack, allowing pollen grains to survive adverse environmental conditions.
Keyword Definitions:
Allergenic Pollen: Pollen proteins that trigger immune responses in humans.
2018
Single Correct Answer MCQ: Which of the following causes seasonal allergies?
(1) Tapetum
(2) Sporopollenin
(3) Pollen grains
(4) Anther wall
Answer & Explanation: The correct answer is (3). Pollen grains of many plant species contain proteins that act as allergens, triggering immune reactions in sensitive individuals, causing symptoms like sneezing, watery eyes, and asthma. Tapetum and sporopollenin are not allergenic, serving structural and nutritive roles.
Keyword Definitions:
Cryopreservation: Storage of gametes or pollen at very low temperatures for future use in breeding.
2021
Single Correct Answer MCQ (Clinical Type): Why is stored pollen useful in crop breeding programs?
(1) To increase allergenicity
(2) To facilitate controlled cross-pollination
(3) To promote tapetum activity
(4) To replace ovules
Answer & Explanation: The correct answer is (2). Cryopreserved pollen can be stored long-term in liquid nitrogen and used for controlled cross-pollination in breeding programs. This ensures genetic diversity and hybrid development, without relying on synchronous flowering times.
Keyword Definitions:
Microspore: Haploid cell that develops into a male gametophyte (pollen grain).
2017
Single Correct Answer MCQ: Microspores develop into:
(1) Tapetum cells
(2) Pollen grains
(3) Ovules
(4) Sepals
Answer & Explanation: The correct answer is (2). Microspores are haploid cells formed in the anther by meiosis of pollen mother cells. They undergo mitotic divisions and differentiate into male gametophytes (pollen grains), essential for sexual reproduction in flowering plants.
Keyword Definitions:
Anther Dehiscence: Release of pollen from anthers for fertilization.
2016
Single Correct Answer MCQ: Which structure releases pollen during anther dehiscence?
(1) Tapetum
(2) Epidermis
(3) Anther wall
(4) Pollen tube
Answer & Explanation: The correct answer is (3). The anther wall undergoes mechanical and enzymatic changes to open and release mature pollen grains. Tapetum degenerates to provide nutrients but does not directly aid in dehiscence.
Keyword Definitions:
Pollen Tube: Structure growing from pollen grain to ovule for sperm delivery.
2015
Single Correct Answer MCQ: The pollen tube is essential for:
(1) Nutrient supply to tapetum
(2) Sperm delivery to ovule
(3) Pollen grain formation
(4) Anther dehiscence
Answer & Explanation: The correct answer is (2). The pollen tube grows from a germinating pollen grain through the style to reach the ovule, delivering male gametes for fertilization. It enables sexual reproduction without requiring direct contact between pollen and ovule.
Keyword Definitions:
Exine Layer: Protective outer layer of pollen composed of sporopollenin.
2019
Assertion-Reason MCQ:
Assertion (A): Exine is chemically resistant and protects pollen grains.
Reason (R): It is composed of sporopollenin, a durable biopolymer.
(1) Both A and R are true, and R is the correct explanation of A
(2) Both A and R are true, but R is not the correct explanation of A
(3) A is true, but R is false
(4) A is false, but R is true
Answer & Explanation: The correct answer is (1). The exine's sporopollenin composition makes it resistant to UV radiation, enzymes, and desiccation, protecting pollen grains during transport and ensuring reproductive success. This chemical durability is key for survival in adverse environments.
Keyword Definitions:
Allergenicity: The potential of pollen proteins to cause allergic reactions.
2018
Fill in the Blanks MCQ: Pollen grains causing allergies contain __________.
(1) Sporopollenin
(2) Proteins
(3) Lipids
(4) DNA
Answer & Explanation: The correct answer is (2). Pollen allergens are mainly proteins present in pollen cytoplasm, triggering immune responses in sensitive individuals. Sporopollenin forms the exine and is inert, while lipids and DNA are not primary allergenic components.
Keyword Definitions:
Crop Breeding: Controlled reproduction in plants to select desirable traits.
2021
Choose the correct statements MCQ:
1. Tapetum supports pollen development but not dehiscence.
2. Exine is made of sporopollenin.
3. Stored pollen can be used in breeding programs.
4. Pollen grains are harmless to humans.
(1) 1, 2, 3 only
(2) 2 and 4 only
(3) 1 and 4 only
(4) All statements are correct
Answer & Explanation: The correct answer is (1). Tapetum nourishes pollen, exine is sporopollenin, and cryopreserved pollen aids breeding programs. Pollen grains, however, can trigger allergies in humans, making statement 4 incorrect.
Keywords:
Stamen: Male reproductive organ of a flower, consisting of filament and anther.
Filament: Stalk of stamen supporting the anther.
Anther: Pollen-producing part of stamen, contains microsporangia.
Connective: Tissue connecting two lobes of an anther.
Placenta: Part of ovary where ovules are attached.
Thalamus: Receptacle of flower where floral organs attach.
Attachment: Point where filament joins anther or other floral structure.
Microsporangia: Pollen sacs in anther producing microspores.
Pollination: Transfer of pollen from anther to stigma.
Bisporangiate: Anther with two lobes, each containing microsporangia.
Floral morphology: Study of form and structure of flowers.
Chapter: Angiosperm Morphology
Topic: Flower Structure
Subtopic: Stamen Morphology
Lead Question - 2016 (Phase 1): Proximal end of the filament of stamen is attached to the:
(1) Anther
(2) Connective
(3) Placenta
(4) Thalamus or petal
Answer: 4
Explanation: The proximal end of the stamen filament is attached to the thalamus (receptacle) or petal. The filament supports the anther, which is the pollen-producing structure. The connective is part of the anther, while the placenta is part of the ovary, not associated with filament attachment.
1. Single Correct Answer MCQ: Which part of stamen produces pollen?
(A) Filament
(B) Anther
(C) Connective
(D) Thalamus
Answer: B
Explanation: The anther is the pollen-producing part of the stamen, containing microsporangia where microspores develop into pollen grains, essential for sexual reproduction in angiosperms.
2. Single Correct Answer MCQ: Connective tissue in an anther connects:
(A) Filament to thalamus
(B) Two lobes of anther
(C) Ovary to ovule
(D) Stigma to style
Answer: B
Explanation: The connective is a sterile tissue that joins the two pollen-bearing lobes of an anther, helping maintain structural integrity of the stamen.
3. Single Correct Answer MCQ: Filament of stamen is generally:
(A) Photosynthetic
(B) Non-photosynthetic stalk
(C) Part of ovary
(D) Nectar-producing
Answer: B
Explanation: The filament is a slender, non-photosynthetic stalk that supports the anther at an optimal position for pollen dispersal and effective pollination.
4. Single Correct Answer MCQ: The anther contains:
(A) Ovules
(B) Microsporangia
(C) Pollen tubes
(D) Style
Answer: B
Explanation: Anthers contain microsporangia, which produce microspores. These microspores develop into pollen grains, the male gametophytes, essential for fertilization in flowering plants.
5. Single Correct Answer MCQ: Which floral part filament is attached to?
(A) Ovary
(B) Thalamus
(C) Style
(D) Stigma
Answer: B
Explanation: The filament’s proximal end is attached to the thalamus or petal base, positioning the anther for optimal pollen release. It is not attached to ovary, style, or stigma.
6. Single Correct Answer MCQ: In bisporangiate anther, number of pollen sacs is:
(A) 1
(B) 2
(C) 4
(D) 6
Answer: C
Explanation: A bisporangiate anther has two lobes, each containing two microsporangia, making a total of four pollen sacs where pollen grains develop.
7. Assertion-Reason MCQ:
Assertion (A): Filament supports the anther for effective pollination.
Reason (R): Filament is photosynthetic and produces pollen.
(A) Both A and R are true, R is correct explanation of A
(B) Both A and R are true, R is NOT correct explanation of A
(C) A is true, R is false
(D) A is false, R is true
Answer: C
Explanation: Filament supports the anther, but it is non-photosynthetic and does not produce pollen. The anther is responsible for pollen production.
8. Matching Type MCQ: Match floral part with function:
1. Filament A. Pollen production
2. Anther B. Supports anther
3. Connective C. Connects anther lobes
4. Thalamus D. Base of flower
(A) 1-B, 2-A, 3-C, 4-D
(B) 1-A, 2-B, 3-D, 4-C
(C) 1-B, 2-C, 3-A, 4-D
(D) 1-D, 2-A, 3-B, 4-C
Answer: A
Explanation: Filament supports the anther, anther produces pollen, connective joins lobes of anther, and thalamus is the floral base where organs are attached.
9. Fill in the Blanks: The ________ is the pollen-producing part, and the ________ is the stalk supporting it.
(A) Filament; Anther
(B) Anther; Filament
(C) Connective; Thalamus
(D) Ovary; Style
Answer: B
Explanation: Anther is the pollen-producing part of the stamen. Filament is the slender stalk supporting the anther at an optimal position for pollination.
10. Choose the Correct Statements:
(A) Filament attaches to thalamus or petal
(B) Connective connects ovary to style
(C) Anther contains microsporangia
(D) Filament produces pollen
(1) A and C
(2) B and D
(3) A, B, C
(4) C and D
Answer: 1
Explanation: Statement A is correct; the filament attaches to thalamus or petal. Statement C is correct; anther contains microsporangia. Statements B and D are incorrect as connective joins anther lobes, and filament does not produce pollen.
Keywords:
Gynoecium: The female reproductive part of a flower consisting of carpels.
Carpel: The basic unit of gynoecium, containing ovary, style, and stigma.
Syncarpous: Gynoecium with two or more carpels fused together.
Tricarpellary: Composed of three carpels.
Liliaceae: Monocot family with flowers often having trimerous symmetry.
Solanaceae: Dicot family including tomato, potato, mostly with syncarpous ovary.
Fabaceae: Legume family with papilionaceous flowers.
Poaceae: Grass family, generally with monocarpellary ovary.
Ovary: Part of carpel containing ovules.
Clinical relevance: Understanding floral structures aids in taxonomy, plant breeding, and pharmacognosy.
Floral morphology: Study of flower structure and arrangement of reproductive parts.
Chapter: Angiosperm Morphology
Topic: Gynoecium Structure
Subtopic: Syncarpous and Apocarpous Flowers
Lead Question - 2016 (Phase 1): Tricarpellary, syncarpous gynoecium is found in flowers of:
(1) Liliaceae
(2) Solanaceae
(3) Fabaceae
(4) Poaceae
Answer: 2
Explanation: Solanaceae flowers typically have a tricarpellary, syncarpous ovary, meaning three carpels are fused. Liliaceae are monocots with trimerous flowers, Fabaceae have papilionaceous flowers, and Poaceae are mostly monocarpellary. Syncarpy ensures proper fertilization and development of fruits like tomato and brinjal.
1. Single Correct Answer MCQ: The fusion of carpels in a flower is called:
(A) Apocarpy
(B) Syncarpy
(C) Polycarpy
(D) Monocarpy
Answer: B
Explanation: Syncarpy refers to the fusion of two or more carpels in a flower, forming a compound ovary, which is essential for coordinated development of ovules and fruit formation.
2. Single Correct Answer MCQ: A monocarpellary ovary is characteristic of which family?
(A) Poaceae
(B) Solanaceae
(C) Fabaceae
(D) Liliaceae
Answer: A
Explanation: Poaceae (grasses) have a single carpel forming the ovary. This simple ovary structure contrasts with tricarpellary, syncarpous gynoecium found in Solanaceae.
3. Single Correct Answer MCQ: The gynoecium of tomato is:
(A) Monocarpellary
(B) Tricarpellary syncarpous
(C) Tricarpellary apocarpous
(D) Bicarpellary syncarpous
Answer: B
Explanation: Tomato belongs to Solanaceae with a tricarpellary, syncarpous ovary, where three carpels fuse to form a single compound ovary enclosing ovules.
4. Single Correct Answer MCQ: Fusion of carpels ensures:
(A) Independent ovule development
(B) Coordinated fertilization and fruit formation
(C) Reduced ovule number
(D) Dispersal of seeds by wind
Answer: B
Explanation: Syncarpy allows carpels to form a single ovary, ensuring coordinated fertilization, proper seed arrangement, and development of a uniform fruit structure.
5. Single Correct Answer MCQ: Number of carpels in a typical Solanaceae flower is:
(A) 1
(B) 2
(C) 3
(D) 4
Answer: C
Explanation: Solanaceae flowers are usually tricarpellary, with three carpels fused into a syncarpous ovary, forming fruit structures like capsules in brinjal or tomato.
6. Single Correct Answer MCQ: Fabaceae flowers have gynoecium type:
(A) Tricarpellary syncarpous
(B) Bicarpellary syncarpous
(C) Monocarpellary
(D) Tricarpellary apocarpous
Answer: C
Explanation: Fabaceae flowers generally have a monocarpellary ovary enclosed within the keel, as in peas and beans, contrasting with tricarpellary, syncarpous ovary of Solanaceae.
7. Assertion-Reason MCQ:
Assertion (A): Syncarpous ovary ensures proper seed arrangement.
Reason (R): Fusion of carpels forms a single compound ovary with coordinated ovule development.
(A) Both A and R are true, R is correct explanation of A
(B) Both A and R are true, R is NOT correct explanation of A
(C) A is true, R is false
(D) A is false, R is true
Answer: A
Explanation: The fusion of carpels in a syncarpous ovary ensures uniform ovule arrangement and coordinated fertilization, facilitating the development of a well-formed fruit.
8. Matching Type MCQ: Match families with their gynoecium type:
1. Solanaceae A. Monocarpellary
2. Poaceae B. Tricarpellary syncarpous
3. Fabaceae C. Monocarpellary
4. Liliaceae D. Tricarpellary syncarpous
(A) 1-B, 2-A, 3-C, 4-D
(B) 1-A, 2-B, 3-C, 4-D
(C) 1-B, 2-C, 3-A, 4-D
(D) 1-D, 2-A, 3-B, 4-C
Answer: A
Explanation: Solanaceae: tricarpellary syncarpous; Poaceae: monocarpellary; Fabaceae: monocarpellary; Liliaceae: tricarpellary syncarpous. These structural differences help in classification and fruit development studies.
9. Fill in the Blanks: A flower with three fused carpels forming a single ovary has a _______ gynoecium which is _______.
(A) Tricarpellary; Syncarpous
(B) Bicarpellary; Apocarpous
(C) Monocarpellary; Syncarpous
(D) Tricarpellary; Apocarpous
Answer: A
Explanation: Tricarpellary refers to three carpels, and syncarpous indicates that these carpels are fused, forming a single compound ovary as seen in Solanaceae flowers.
10. Passage-based MCQ:
Passage: A botanist observes a flower with three carpels fused into a single ovary. The ovules are arranged in locules within the ovary. Fruits like tomato and brinjal develop from such flowers.
Question: The gynoecium type of this flower is:
(A) Monocarpellary
(B) Tricarpellary syncarpous
(C) Tricarpellary apocarpous
(D) Bicarpellary syncarpous
Answer: B
Explanation: The passage describes a tricarpellary, syncarpous gynoecium, where three carpels are fused forming a single ovary, as observed in Solanaceae, facilitating coordinated fruit and seed development.
Keywords:
Papilionaceous corolla: A butterfly-shaped flower structure typical of Fabaceae family.
Standard petal: The large, uppermost petal in a papilionaceous flower.
Carina: The two fused lower petals forming a keel in papilionaceous flowers.
Vexillum: Another name for the standard petal in papilionaceous corolla.
Pappus: Modified calyx of Asteraceae aiding in seed dispersal.
Corona: Crown-like structure present in some flowers like Narcissus.
Floral morphology: Study of flower structures and arrangements.
Keel: Structure formed by fusion of lower petals in papilionaceous corolla.
Fabaceae: Legume family of plants showing papilionaceous flowers.
Pollination: Transfer of pollen, often aided by corolla shape.
Clinical relevance: Understanding floral morphology aids in taxonomy and medicinal plant identification.
Chapter: Angiosperm Morphology
Topic: Flower Structure
Subtopic: Papilionaceous Flowers
Lead Question - 2016 (Phase 1): The standard petal of a papilionaceous corolla is also called :
(1) Carina
(2) Pappus
(3) Vexillum
(4) Corona
Answer: 3
Explanation: In papilionaceous flowers, the large uppermost petal is called the standard or vexillum. The two fused lower petals form the keel (carina). Pappus and corona are unrelated floral structures seen in other plant families, hence Vexillum is correct.
1. Single Correct Answer MCQ: The two fused lower petals of a papilionaceous corolla form the:
(A) Standard
(B) Carina
(C) Vexillum
(D) Corona
Answer: B
Explanation: The lower petals fuse to form the keel or carina, which encloses reproductive organs, aiding in efficient pollination in Fabaceae family flowers.
2. Single Correct Answer MCQ: Which plant family commonly shows papilionaceous flowers?
(A) Solanaceae
(B) Fabaceae
(C) Asteraceae
(D) Liliaceae
Answer: B
Explanation: Papilionaceous corolla is characteristic of the Fabaceae (legume) family, with butterfly-shaped flowers adapted for insect pollination.
3. Single Correct Answer MCQ: In a papilionaceous flower, the lateral petals are called:
(A) Vexillum
(B) Wings
(C) Carina
(D) Pappus
Answer: B
Explanation: Lateral petals are termed wings, which assist in guiding pollinators toward the reproductive organs and protecting the keel.
4. Single Correct Answer MCQ: The floral structure aiding in seed dispersal in Asteraceae is called:
(A) Carina
(B) Vexillum
(C) Pappus
(D) Corona
Answer: C
Explanation: Pappus is a modified calyx in Asteraceae family flowers that helps in wind dispersal of seeds, not found in Fabaceae flowers.
5. Single Correct Answer MCQ: Which corolla type helps in specialized insect pollination?
(A) Papilionaceous
(B) Regular
(C) Actinomorphic
(D) Sympetalous
Answer: A
Explanation: Papilionaceous flowers have a bilaterally symmetrical corolla with standard, wings, and keel, specialized for pollinator-guided reproduction.
6. Single Correct Answer MCQ: The uppermost petal of a Fabaceae flower is called:
(A) Corona
(B) Carina
(C) Vexillum
(D) Pappus
Answer: C
Explanation: Vexillum is the uppermost, large standard petal in papilionaceous corolla, serving as a visual cue for pollinators.
7. Assertion-Reason MCQ:
Assertion (A): Papilionaceous flowers show bilateral symmetry.
Reason (R): The standard petal, wings, and keel are arranged asymmetrically.
(A) Both A and R are true, R is correct explanation of A
(B) Both A and R are true, R is NOT correct explanation of A
(C) A is true, R is false
(D) A is false, R is true
Answer: A
Explanation: Papilionaceous corolla is bilaterally symmetrical due to asymmetric arrangement of standard, wings, and keel, ensuring directional pollination by insects.
8. Matching Type MCQ: Match floral parts with their description:
1. Vexillum A. Standard petal
2. Wings B. Lateral petals
3. Carina C. Fused lower petals
4. Pappus D. Seed dispersal structure
(A) 1-A, 2-B, 3-C, 4-D
(B) 1-B, 2-A, 3-C, 4-D
(C) 1-A, 2-C, 3-B, 4-D
(D) 1-D, 2-B, 3-C, 4-A
Answer: A
Explanation: The standard petal is Vexillum, lateral petals are wings, fused lower petals form carina, and Pappus is unrelated, aiding seed dispersal in other plant families.
9. Fill in the Blanks: The large uppermost petal of a papilionaceous flower is called _______ and the fused lower petals are called _______.
(A) Vexillum; Carina
(B) Carina; Vexillum
(C) Wings; Pappus
(D) Corona; Keel
Answer: A
Explanation: The uppermost standard petal is Vexillum; the lower fused petals form the keel or carina, enclosing reproductive organs and facilitating pollination.
10. Passage-based MCQ:
Passage: A botanist observes a legume flower. The upper petal is large and showy, lateral petals are small, and two fused lower petals form a protective structure around stamens. This arrangement facilitates insect pollination.
Question: What is the name of the upper petal?
(A) Carina
(B) Pappus
(C) Vexillum
(D) Corona
Answer: C
Explanation: The passage describes papilionaceous floral structure; the large upper petal is the Vexillum (standard petal), lateral petals are wings, and fused lower petals form the keel for effective pollination.