Improvement in Food Production

Topic: Biological Control of Pests; Subtopic: Role of Natural Enemies and Pest Management

Keyword Definitions:

• Aphids: Small sap-sucking insects that damage plants by feeding on phloem sap.

• Mosquitoes: Insects known for biting and transmitting diseases such as malaria and dengue.

• Lady bird: A small beetle that preys on aphids and acts as a biological pest controller.

• Dragonflies: Insects that feed on mosquitoes and other small pests, helping in biological control.

• Natural Pest Controllers: Living organisms like predators or parasites that control pest populations naturally.

Lead Question – 2024 (Jhajjhar)

Given below are two statements:

Statement I: Aphids and mosquitoes are natural pests.

Statement II: Lady bird and dragonflies are natural pest controllers.

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:

Aphids and mosquitoes are indeed pests that harm plants and animals, while lady birds and dragonflies feed on them, making them natural pest controllers. Hence, Statement I is incorrect and Statement II is correct. This highlights the importance of biological control in agriculture, where natural predators maintain ecological balance without chemical pesticides. Answer: 4

1. Which of the following is a biological control agent against aphids?

1. Butterfly

2. Lady bird beetle

3. Honey bee

4. Ant

Explanation:

Lady bird beetles (Coccinellidae family) are efficient biological control agents that feed on aphids, scales, and mealybugs. They help naturally regulate pest populations in agricultural crops, reducing dependence on synthetic pesticides. Their introduction in pest-prone fields supports sustainable farming and integrated pest management strategies. Answer: 2

2. Which of the following statements correctly defines biological control?

1. Use of chemicals to control pests

2. Use of natural enemies to manage pest population

3. Genetic modification of crops to resist pests

4. Use of fertilizers to boost crop yield

Explanation:

Biological control refers to the use of predators, parasites, or pathogens to suppress pest populations. It is an eco-friendly, self-sustaining, and cost-effective approach that maintains pest numbers below economic thresholds without polluting the environment. Examples include lady bird beetles against aphids and Bacillus thuringiensis against caterpillars. Answer: 2

3. Which microorganism is used to control insect larvae in crops?

1. Rhizobium

2. Azospirillum

3. Bacillus thuringiensis

4. Aspergillus niger

Explanation:

Bacillus thuringiensis (Bt) is a gram-positive bacterium producing crystal proteins (Cry toxins) that kill insect larvae, especially of Lepidopteran pests. When ingested, these toxins disrupt the gut lining, causing death. Bt genes have been introduced into transgenic crops like Bt cotton to enhance pest resistance. Answer: 3

4. Which among the following acts as a natural enemy of mosquitoes?

1. Ants

2. Dragonflies

3. Termites

4. Moths

Explanation:

Dragonflies are major predators of mosquitoes, both in their larval (aquatic nymph) and adult stages. Their presence helps in controlling mosquito populations naturally, reducing the spread of diseases like malaria and dengue. Hence, they serve as efficient biological pest control agents. Answer: 2

5. Which of the following is not an example of biological pest control?

1. Use of dragonflies against mosquitoes

2. Use of lady bird beetles against aphids

3. Spraying insecticides on crops

4. Introducing Trichogramma to control borers

Explanation:

Spraying insecticides involves chemical control, not biological control. Biological control relies on natural enemies such as predators (lady bird beetles), parasitoids (Trichogramma), and pathogens (Bacillus thuringiensis) to suppress pests without harming the ecosystem or causing pesticide resistance. Answer: 3

6. Which of the following organisms helps in controlling the population of crop borers?

1. Trichogramma

2. Rhizobium

3. Mycorrhiza

4. Nitrosomonas

Explanation:

Trichogramma species are tiny parasitic wasps that lay eggs inside the eggs of crop borers and other lepidopterans. The developing larvae consume the host egg, preventing pest emergence. They are used widely in integrated pest management programs for cotton, sugarcane, and rice crops. Answer: 1

Assertion-Reason Type

7. Assertion (A): Use of pesticides has adverse environmental impacts.

Reason (R): Biological control methods promote natural balance without chemical hazards.

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 and interrelated. Chemical pesticides pollute soil and water and can harm non-target species, while biological control utilizes natural enemies like predators, parasitoids, or pathogens to maintain pest populations at low levels, restoring ecological balance naturally and safely. Answer: 1

Matching Type

8. Match List-I with List-II:

A. Aphids – I. Lady bird beetle

B. Mosquito larvae – II. Dragonfly

C. Stem borer eggs – III. Trichogramma

D. Cotton bollworm – IV. Bacillus thuringiensis

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-I, B-III, C-II, D-IV

Explanation:

Lady bird beetles feed on aphids, dragonflies prey on mosquitoes, Trichogramma parasitizes eggs of stem borers, and Bacillus thuringiensis kills larvae like cotton bollworm. This demonstrates a range of biological control interactions beneficial in pest management programs. Answer: 1

Fill in the Blanks Type

9. The bacterium __________ is used in the preparation of biopesticides effective against Lepidopteran pests.

1. Rhizobium

2. Bacillus thuringiensis

3. Clostridium tetani

4. Lactobacillus acidophilus

Explanation:

Bacillus thuringiensis (Bt) produces insecticidal proteins (Cry toxins) that destroy gut cells of insect larvae when consumed. These toxins are used in organic farming as biopesticides and in developing genetically modified pest-resistant crops such as Bt cotton and Bt brinjal. Answer: 2

Choose the Correct Statements (Statement I & Statement II)

10. Statement I: Trichoderma is a fungus used in biological control.

Statement II: It enhances plant immunity and suppresses soil-borne pathogens.

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:

Both statements are correct. Trichoderma is a genus of fungi used as a biocontrol agent against several plant pathogens. It colonizes roots, produces antifungal metabolites, and induces systemic resistance in plants, promoting healthy growth and sustainable agriculture. Answer: 1

Topic: Somatic Hybridization; Subtopic: Protoplast Fusion and Applications

Keyword Definitions:

• Somatic Hybridization: A technique in plant biotechnology where protoplasts from two different plant varieties are fused to combine desirable traits.

• Protoplasts: Plant cells with the cell wall removed, capable of fusion and regeneration into whole plants.

• Somatic embryos: Embryos developed from somatic cells, used in plant tissue culture for regeneration.

• Callus: Undifferentiated plant tissue mass produced in culture, which can give rise to whole plants.

• Pollens: Male gametophytes involved in sexual reproduction in plants.

Lead Question – 2024

Which of the following are fused in somatic hybridization involving two varieties of plants?

(1) Somatic embryos
(2) Protoplasts
(3) Pollens
(4) Callus

Explanation:

In somatic hybridization, protoplasts from two genetically distinct plant varieties are fused using chemical or electrical methods. The fused protoplast develops into a hybrid callus that can regenerate into a whole plant, combining traits from both parents. Somatic embryos or pollens are not used in the fusion process. Callus may be formed after fusion but is not the material fused. Therefore, the correct answer is option (2) Protoplasts, as they are the units directly fused in somatic hybridization to produce somatic hybrids.

1. Which method is commonly used to fuse protoplasts in somatic hybridization?

(1) Agrobacterium-mediated transformation
(2) Electrofusion
(3) Cross-pollination
(4) Grafting

Explanation: Protoplasts from two plant varieties are commonly fused using electrofusion, which applies an electric field to induce membrane fusion. Chemical methods using polyethylene glycol (PEG) are also used. This fusion enables somatic hybridization for combining desirable traits. Hence, option (2) Electrofusion is correct.

2. What is a protoplast?

(1) Plant cell without a nucleus
(2) Plant cell without a cell wall
(3) Plant embryo
(4) Undifferentiated callus

Explanation: A protoplast is a plant cell from which the cell wall has been enzymatically removed, leaving the plasma membrane intact. Protoplasts are totipotent and can be fused or regenerated into whole plants. Hence, option (2) Plant cell without a cell wall is correct.

3. Callus formed after protoplast fusion can be used to:

(1) Produce hybrid plants
(2) Isolate DNA
(3) Generate pollen grains
(4) Produce antibiotics

Explanation: After protoplast fusion, the resulting callus is an undifferentiated mass of cells that can be cultured to regenerate whole somatic hybrid plants, combining traits from both parents. It serves as a bridge between protoplast fusion and plant regeneration. Therefore, option (1) Produce hybrid plants is correct.

4. Which of the following is a direct outcome of somatic hybridization?

(1) Formation of zygote
(2) Production of genetically identical clones
(3) Generation of somatic hybrids combining parental traits
(4) Self-pollination

Explanation: Somatic hybridization fuses protoplasts of two distinct plants, producing somatic hybrids that combine traits from both parents. Unlike sexual reproduction, this process does not involve gametes or zygotes but enables novel genetic combinations. Hence, option (3) Generation of somatic hybrids combining parental traits is correct.

5. Which plant tissue is totipotent and can regenerate whole plants in culture?

(1) Leaf epidermis
(2) Protoplast
(3) Pollen grain
(4) Secondary xylem

Explanation: Protoplasts are totipotent, meaning they can regenerate into a complete plant under suitable culture conditions. This property is exploited in somatic hybridization and plant tissue culture. Pollen or xylem cannot regenerate whole plants. Hence, option (2) Protoplast is correct.

6. Assertion–Reason Type Question

Assertion (A): Somatic hybridization allows combination of traits from two different plant varieties.
Reason (R): Protoplasts from two varieties can be fused and regenerated into a hybrid plant.

Explanation: Both Assertion and Reason are true and R correctly explains A. Fusing protoplasts bypasses sexual barriers and produces hybrid plants with combined traits. Therefore, the correct option is (1) Both A and R are true and R is the correct explanation of A.

7. Matching Type Question

Match the plant part with its role in somatic hybridization:
A. Protoplast – I. Fused to form hybrid
B. Callus – II. Regenerates into plant
C. Somatic embryo – III. Used to initiate culture
D. Pollen – IV. Male gamete
(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–III, C–I, D–II

Explanation: Protoplasts are fused to form hybrids, callus regenerates into whole plants, somatic embryos can be cultured to initiate regeneration, and pollen is unrelated to somatic hybridization. Hence, option (1) is correct.

8. Fill in the Blanks Question

Somatic hybridization is achieved by fusing ______ from two plant varieties and regenerating them into a hybrid plant.

(1) Protoplasts
(2) Pollens
(3) Callus
(4) Leaf sections

Explanation: Protoplasts, being plant cells without cell walls, are fused to combine genetic material and regenerate hybrid plants. Therefore, option (1) Protoplasts is correct.

9. Choose the Correct Statements (Statement I & II)

Statement I: Somatic hybridization bypasses sexual incompatibility.
Statement II: Pollens are directly fused to form somatic hybrids.

Explanation: Statement I is true because protoplast fusion allows hybridization across species barriers. Statement II is false as pollens are male gametes and are not fused in somatic hybridization. Correct answer: (2) Statement I true, Statement II false.

10. Which part of the plant is actually fused to produce somatic hybrids?

(1) Somatic embryos
(2) Protoplasts
(3) Pollen grains
(4) Callus

Explanation: The fundamental unit fused in somatic hybridization is the protoplast, a plant cell without a cell wall. This fusion combines genetic material from two plant varieties to create hybrid cells. The fused protoplasts can divide and form callus, which then regenerates into a complete hybrid plant, combining traits from both parents. Somatic embryos or pollens are not fused in this process. Therefore, option (2) Protoplasts is correct.

Topic: Assisted Reproductive Technologies; Subtopic: Multiple Ovulation Embryo Transfer (MOET)

Keyword Definitions:

• MOET: Multiple Ovulation Embryo Transfer, a technique to produce multiple embryos from a super-ovulated donor cow for transfer to surrogate mothers.

• Super-ovulation: Hormonal induction in female animals to produce multiple eggs in a single cycle.

• Embryo Transfer: Process of transferring fertilized embryos from donor to recipient female for gestation.

• Artificial Insemination: Introduction of sperm into the female reproductive tract by human intervention.

• Elite Bull: Male with desirable traits for breeding to improve herd genetics.

• Non-surgical Recovery: Collecting embryos without invasive surgery, typically via flushing of the uterus.

• Herd Improvement: Enhancement of livestock traits such as milk production, disease resistance, or growth rate.

• Surrogate Mother: Female receiving embryos from donor for gestation.

• Embryo Stages: Early development stages, typically 4- to 6-cell stage, suitable for transfer.

• Hormonal Treatment: Administration of FSH or other hormones to stimulate multiple ovulations.

• Genetic Advancement: Accelerated improvement of livestock characteristics using reproductive technologies.

Lead Question - 2023 (Manipur):

Select the incorrect statement with respect to Multiple Ovulation Embryo Transfer (MOET) technology.

1. Fertilised eggs at 4 to 6 cells - stages are recovered non-surgically from a super-ovulating cow and transferred to a surrogate mother.
2. It is used to increase herd size in a short time
3. Cow is administered with hormones to induce super-ovulation.
4. Super-ovulating cow is either mated with an elite bull or is artificially inseminated

Explanation: Correct answer is option 1. In MOET, fertilized eggs are typically recovered surgically via uterine flushing, not always non-surgically. The technique involves hormone-induced super-ovulation, mating or AI with elite bulls, and transfer of embryos to surrogate mothers. It accelerates herd improvement by increasing offspring from genetically superior cows. Understanding MOET includes recognizing hormonal stimulation, embryo collection methods, surrogate usage, and herd enhancement goals. While other statements are correct about its applications, the recovery process is usually surgical to ensure viable embryos, making option 1 the incorrect statement.

Guessed MCQs:

1. Single Correct Answer MCQ: Super-ovulation in MOET is induced by:
(A) FSH hormones
(B) LH hormones
(C) Estrogen
(D) Progesterone
Explanation: Correct answer is (A). Follicle Stimulating Hormone (FSH) is administered to donor cows to stimulate multiple follicles to mature simultaneously. This allows recovery of multiple embryos for transfer. LH, estrogen, and progesterone regulate natural cycles but are not the primary agents for super-ovulation in MOET. Proper hormonal control ensures high-quality embryo production, improving herd genetics efficiently.

2. Single Correct Answer MCQ: Surrogate mothers in MOET are used to:
(A) Provide hormonal treatment
(B) Gestate transferred embryos
(C) Induce super-ovulation
(D) Produce sperm
Explanation: Correct answer is (B). Surrogate mothers carry embryos from donor cows to term, enabling production of genetically superior offspring. They do not receive super-ovulation treatments nor produce gametes. Selection of healthy surrogates ensures successful implantation, gestation, and birth. Understanding the surrogate’s role is key for reproductive biotechnology, herd improvement, and maximizing genetic potential through embryo transfer programs.

3. Single Correct Answer MCQ: MOET primarily aims to:
(A) Increase herd size quickly
(B) Reduce milk production
(C) Prevent diseases
(D) Enhance natural mating
Explanation: Correct answer is (A). MOET accelerates herd improvement by producing multiple offspring from genetically superior cows within a single reproductive cycle. It does not reduce production, prevent diseases, or replace natural mating entirely, although it complements selective breeding. Recognizing its purpose clarifies its role in modern livestock management, improving genetic traits and economic efficiency in farming.

4. Single Correct Answer MCQ: Embryos for transfer in MOET are usually collected at:
(A) Zygote stage
(B) 4- to 6-cell stage
(C) Blastocyst stage
(D) Gamete stage
Explanation: Correct answer is (B). Embryos are recovered at the 4- to 6-cell stage to ensure viability and successful implantation in surrogate mothers. Zygote or gamete stages are too early, and blastocyst stage is later and may reduce transfer success. Correct timing maximizes live birth rates and ensures efficient use of donor cow embryos for genetic improvement.

5. Single Correct Answer MCQ: Donor cows in MOET are mated with:
(A) Random bull
(B) Elite bull
(C) Any cow
(D) Surrogate mother
Explanation: Correct answer is (B). Donor cows are mated with genetically superior elite bulls or artificially inseminated to produce high-quality embryos. This selective breeding accelerates genetic improvement of the herd. Random mating or use of non-elite animals reduces effectiveness. Elite bull selection is critical for enhancing traits like milk yield, disease resistance, and growth rate in livestock management.

6. Single Correct Answer MCQ: Artificial insemination in MOET is used to:
(A) Recover embryos
(B) Stimulate super-ovulation
(C) Fertilize eggs of super-ovulated donor
(D) Gestate embryos
Explanation: Correct answer is (C). AI ensures fertilization of multiple eggs from a super-ovulated donor cow without the need for natural mating. This allows controlled genetic combinations with elite bulls, improving herd quality. Embryo recovery and gestation are separate steps, and hormone-induced super-ovulation occurs prior to insemination. Understanding AI’s role is crucial for reproductive efficiency and genetic management in MOET programs.

7. Assertion-Reason MCQ:
Assertion (A): MOET technology accelerates genetic improvement in livestock.
Reason (R): Multiple embryos from elite donors are transferred to surrogates in a single cycle.
(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: Option (A) is correct. By producing and transferring multiple embryos from genetically superior cows, MOET accelerates herd improvement in fewer cycles. The reason explains how multiple ovulations, embryo recovery, and surrogate transfer combine to achieve rapid genetic advancement in livestock populations, enhancing desirable traits efficiently and economically.

8. Matching Type MCQ: Match step with function in MOET:
1. Super-ovulation    A. Fertilization
2. Mating/AI    B. Induce multiple follicles
3. Embryo recovery    C. Collect embryos
4. Embryo transfer    D. Gestate embryos
(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-B, 3-C, 4-A
Explanation: Correct option is 1-B, 2-A, 3-C, 4-D. Super-ovulation induces multiple follicles (1-B), mating or AI fertilizes eggs (2-A), embryos are collected from donor (3-C), and transferred to surrogate for gestation (4-D). This sequence ensures maximum embryo production, successful implantation, and rapid herd improvement through MOET technology.

9. Fill in the Blanks / Completion MCQ: MOET is used to increase herd size in a ______ period.
(A) Short
(B) Long
(C) Undefined
(D) Variable
Explanation: Short is correct. MOET enables multiple offspring from superior donors in a single cycle, rapidly increasing herd size and genetic quality. It is designed for accelerated breeding programs and herd expansion. Understanding time efficiency highlights MOET’s advantage over conventional breeding methods, allowing fast dissemination of desirable traits and improved productivity within livestock populations.

10. Choose the correct statements MCQ:
Statement I: MOET involves super-ovulation and embryo transfer.
Statement II: MOET does not use surrogate mothers.
(A) Only Statement I is correct
(B) Only Statement II is correct
(C) Both I and II are correct
(D) Neither I nor II is correct
Explanation: Option (A) is correct. MOET requires hormonal super-ovulation of donor cows and embryo transfer to surrogate mothers for gestation. Statement II is incorrect as surrogate mothers are essential for carrying embryos. Understanding the role of each step ensures proper application of MOET in livestock management, maximizing genetic improvement and reproductive efficiency in controlled breeding programs.

Topic: Breeding Methods in Animals; Subtopic: Inbreeding and Outbreeding

Keyword Definitions:
• Inbreeding: Mating of closely related individuals within the same breed for 4–6 generations to improve desirable traits.
• Outbreeding: Mating of unrelated animals to increase genetic diversity.
• Homozygosity: Presence of identical alleles at a gene locus, increased by inbreeding.
• Hybrid Vigour: Increased vitality and productivity seen in offspring of unrelated parents due to heterozygosity.

Lead Question (2023):
Which one of the following is NOT an advantage of inbreeding?
(1) Elimination of less desirable genes and accumulation of superior genes takes place due to it.
(2) It decreases the productivity of inbred population after continuous inbreeding.
(3) It decreases homozygosity.
(4) It exposes harmful recessive genes that are eliminated by selection.

Explanation (Answer: 3)
Inbreeding increases homozygosity, helping expose harmful recessive genes which can be eliminated by selection, improving genetic purity. It also allows accumulation of superior genes. However, excessive inbreeding may cause inbreeding depression, reducing productivity. Thus, the statement “It decreases homozygosity” is incorrect since inbreeding actually increases it. Correct answer is option (3).

1. Continuous inbreeding among closely related animals leads to:
(1) Inbreeding depression
(2) Increased heterozygosity
(3) Genetic diversity
(4) Hybrid vigour
Explanation: Prolonged inbreeding increases homozygosity and may result in inbreeding depression, where fertility and productivity reduce due to expression of harmful recessive genes. It decreases genetic diversity and vitality. Controlled inbreeding, however, is useful for developing pure lines. Hence, the correct answer is (1) Inbreeding depression.

2. Which of the following breeding methods produces hybrid vigour?
(1) Inbreeding
(2) Outcrossing
(3) Selfing
(4) Line breeding
Explanation: Hybrid vigour or heterosis arises when genetically distinct animals are crossed, resulting in superior growth, fertility, and production traits. Outcrossing and crossbreeding promote heterozygosity, unlike inbreeding, which increases homozygosity. Therefore, hybrid vigour results from outcrossing. Hence, the correct answer is (2) Outcrossing.

3. The process of mating animals of the same breed but not closely related is called:
(1) Outcrossing
(2) Crossbreeding
(3) Inbreeding
(4) Hybridization
Explanation: Outcrossing involves mating unrelated animals of the same breed, usually for 4–6 generations. It helps restore fertility and vigour lost due to continuous inbreeding. Outcrossing introduces new genetic combinations, maintaining breed characteristics while preventing inbreeding depression. Therefore, the correct answer is (1) Outcrossing.

4. In animal breeding, the mating between different breeds is known as:
(1) Outcrossing
(2) Crossbreeding
(3) Hybridization
(4) Line breeding
Explanation: Crossbreeding involves mating animals of two different breeds to combine desirable traits of both parents. It enhances productivity and adaptability, often resulting in hybrid vigour. For example, Hisardale sheep is a cross between Bikaneri ewes and Merino rams. Hence, the correct answer is (2) Crossbreeding.

5. Which one of the following is true for inbreeding depression?
(1) Increase in fertility
(2) Increase in milk yield
(3) Decrease in vigour and fertility
(4) Increase in resistance power
Explanation: Inbreeding depression refers to a decline in fertility, vigour, and productivity due to excessive inbreeding. It occurs because deleterious recessive alleles become homozygous and express harmful effects. Controlled outcrossing or crossbreeding can restore vigour. Hence, the correct answer is (3) Decrease in vigour and fertility.

6. Cross between indigenous and exotic breeds of cattle is done to:
(1) Produce hybrids with high milk yield
(2) Reduce milk yield
(3) Increase homozygosity
(4) Make animals infertile
Explanation: Crossbreeding between indigenous and exotic cattle breeds combines the adaptability of native breeds with high milk yield of exotic breeds. The progeny show hybrid vigour, with better productivity and disease resistance. For example, Karan Swiss and Karan Fries are crossbred cattle. Hence, the correct answer is (1).

7. Assertion-Reason Type:
Assertion (A): Inbreeding increases homozygosity.
Reason (R): It allows recessive alleles to pair up, revealing their effects.
(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: Inbreeding increases homozygosity as genetically similar parents pass identical alleles to offspring. This exposes recessive alleles, enabling selection against harmful genes. Thus, both A and R are true, and R correctly explains A. Correct answer: (1).

8. Matching Type:
Match List I with List II:
A. Outcrossing     I. Different breeds
B. Crossbreeding     II. Same breed, unrelated
C. Interspecific hybridization     III. Different species
(1) A-II, B-I, C-III
(2) A-I, B-II, C-III
(3) A-III, B-I, C-II
(4) A-II, B-III, C-I
Explanation: Outcrossing involves unrelated animals of the same breed, crossbreeding involves animals of different breeds, and interspecific hybridization occurs between different species. These methods improve traits and maintain genetic health. Hence, the correct match is (1) A-II, B-I, C-III.

9. Fill in the Blanks:
The mating between animals of two different species is called ________.
(1) Crossbreeding
(2) Interspecific hybridization
(3) Outcrossing
(4) Line breeding
Explanation: Interspecific hybridization is mating between two different species to combine desirable traits. The offspring may or may not be fertile. An example is mule (male donkey × female horse). It helps in developing hybrids with unique traits. Hence, the correct answer is (2).

10. Choose the correct statements:
Statement I: Inbreeding helps in selection of superior animals.
Statement II: Continuous inbreeding reduces fertility and productivity.
(1) Both statements are true
(2) Both statements are false
(3) Only Statement I is true
(4) Only Statement II is true
Explanation: Inbreeding helps identify superior genotypes by exposing recessive genes, but continuous inbreeding can cause inbreeding depression leading to reduced fertility and productivity. Therefore, both statements are correct. Hence, the correct answer is (1).

Topic : Animal Breeding; Subtopic : Inbreeding in Animals

Keyword Definitions :

• Inbreeding : Mating between closely related individuals to increase homozygosity and develop pure lines.

• Homozygosity : Presence of identical alleles for a gene in a diploid organism.

• Heterozygosity : Presence of different alleles for a gene in a diploid organism.

• Pure Lines : Populations that are genetically uniform and stable over generations.

• Recessive Genes : Genes whose traits are expressed only when homozygous.

• Selection : Process of choosing individuals with desirable traits for breeding.

• Accumulation of Superior Genes : Concentration of desirable alleles in progeny through controlled breeding.

• Genetic Disorders : Conditions caused by harmful alleles, often exposed in inbreeding.

• Animal Breeding : Science of mating animals to improve genetic traits.

• Hybrid Vigour : Improved traits in offspring due to crossing unrelated individuals, opposite of inbreeding.

Lead Question - 2022 (Ganganagar)
Select the incorrect statement with respect to inbreeding of animals.
1. It is used for evolving pure lines in cattle.
2. It helps in accumulation of superior genes and elimination of less desirable genes.
3. It decreases homozygosity.
4. It exposes harmful recessive genes that are eliminated by selection

Explanation : Inbreeding increases homozygosity in a population, making individuals more genetically uniform and aiding in developing pure lines. It helps accumulate desirable genes and expose harmful recessive alleles for elimination through selection. Statement 3 is incorrect because inbreeding does not decrease homozygosity; it increases it. Therefore, the correct answer is Option 3.

1. Single Correct Answer:
Which breeding method is used to create genetically uniform pure lines?
1. Outbreeding
2. Crossbreeding
3. Inbreeding
4. Hybridization

Explanation : Inbreeding is employed to create pure lines by mating closely related individuals. It increases homozygosity and stabilizes desirable traits over generations. Outbreeding, crossbreeding, and hybridization increase heterozygosity and variation. Hence, the correct answer is Option 3.

2. Single Correct Answer:
Exposure of harmful recessive genes in a population is a consequence of:
1. Outbreeding
2. Inbreeding
3. Hybrid vigor
4. Random mating

Explanation : Inbreeding increases homozygosity, which exposes harmful recessive genes. These genes can then be eliminated by selection, improving the population's genetic quality. Outbreeding and hybrid vigor mask recessive alleles, while random mating does not target harmful alleles. Hence, Option 2 is correct.

3. Single Correct Answer:
Which is a disadvantage of inbreeding?
1. Increased hybrid vigor
2. Expression of deleterious alleles
3. Greater genetic diversity
4. Reduced selection efficiency

Explanation : A key disadvantage of inbreeding is that it exposes deleterious recessive alleles, leading to inbreeding depression and reduced fitness. Inbreeding decreases genetic diversity and does not increase hybrid vigor. Selection efficiency is enhanced as harmful alleles are exposed. Hence, Option 2 is correct.

4. Single Correct Answer:
Accumulation of superior genes is achieved in:
1. Inbreeding
2. Outbreeding
3. Random mating
4. Hybridization

Explanation : Inbreeding allows concentration of superior genes and removal of undesirable alleles by selection. Outbreeding and hybridization introduce genetic variation and may dilute desirable traits. Random mating does not selectively accumulate superior genes. Hence, Option 1 is correct.

5. Single Correct Answer:
Which method is used to evolve pure lines in cattle?
1. Inbreeding
2. Crossbreeding
3. Outbreeding
4. Intergeneric hybridization

Explanation : Inbreeding is specifically used in animal breeding to develop pure lines with homozygous desirable traits. Crossbreeding and outbreeding are used to introduce variation, and intergeneric hybridization combines genes from different genera. Hence, Option 1 is correct.

6. Single Correct Answer:
Which of the following decreases heterozygosity?
1. Inbreeding
2. Outbreeding
3. Crossbreeding
4. Random mating

Explanation : Inbreeding increases homozygosity, thereby reducing heterozygosity in a population. Outbreeding and crossbreeding increase heterozygosity, while random mating maintains allele frequencies. Hence, Option 1 is correct.

7. Assertion-Reason:
Assertion (A): Inbreeding exposes harmful recessive genes.
Reason (R): Inbreeding increases homozygosity in a population.
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 : Inbreeding increases homozygosity, which unmasks harmful recessive alleles. This allows selection to remove deleterious traits, improving genetic quality. Both assertion and reason are true, and the reason correctly explains the assertion. Hence, Option 1 is correct.

8. Matching Type:
Match List-I with List-II:
List-I      List-II
(a) Inbreeding      (i) Increased homozygosity
(b) Outbreeding      (ii) Increased heterozygosity
(c) Hybridization      (iii) Pure line development
(d) Selection      (iv) Removal of deleterious alleles
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 : Inbreeding increases homozygosity, outbreeding increases heterozygosity, hybridization is used for pure line or trait introduction, and selection removes deleterious alleles. Correct matching is (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv). Hence, Option 1 is correct.

9. Fill in the Blank:
Inbreeding is primarily used to increase _______ in a population.
1. Heterozygosity
2. Homozygosity
3. Mutation rate
4. Gene flow

Explanation : Inbreeding increases homozygosity by mating closely related individuals. This stabilizes desired traits and exposes harmful recessive alleles for elimination. Heterozygosity decreases, mutation rate is not affected directly, and gene flow is unrelated. Hence, Option 2 is correct.

10. Choose the correct statements:
Statement I: Inbreeding helps in evolving pure lines.
Statement II: Inbreeding decreases homozygosity.
1. Both statements are correct
2. Only Statement I is correct
3. Only Statement II is correct
4. Both statements are incorrect

Explanation : Inbreeding increases homozygosity and aids in developing pure lines. Statement I is correct, while Statement II is incorrect because homozygosity increases, not decreases. Hence, Option 2 is correct.

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: Plant Breeding; Topic: Hybridization Techniques; Subtopic: Artificial Hybridization and Pollination Control

Keyword Definitions:

• Artificial hybridization: Deliberate crossing of selected parent plants to combine desired traits.

• Emasculation: Removal of anthers from a flower to prevent self-pollination.

• Stigma: Female part of a flower where pollen lands and germinates.

• Pollen: Male gametophyte responsible for fertilization.

• Protogyny: Condition in bisexual flowers where the female organ matures before male organ.

• Bagging: Covering flowers to prevent unwanted pollination.

• Unisexual flowers: Flowers having either male or female reproductive organs.

• Bisexual flowers: Flowers with both stamens and carpels.

• Cross-pollination: Transfer of pollen from one plant to the stigma of another plant.

• Controlled pollination: Ensuring only selected pollen fertilizes the flower.

• Hybrid seed production: Seeds obtained through controlled crossing of selected parents.

Lead Question - 2022 (Ganganagar)

To ensure that only the desired pollens fall on the stigma in artificial hybridization process:

(a) the female flower buds of plant producing unisexual flower need not be bagged.

(b) there is no need to emasculate unisexual flowers of selected female parent

(c) emasculated flowers are to be bagged immediately after cross pollination

(d) emasculated flowers are to be bagged after removal of anthers

(e) bisexual flowers, showing protogyny are never selected for cross

Choose the correct answer from the options given below:

1. (a), (b) and (c) only

2. (b), (c) and (d) only

3. (b), (c) and (e) only

4. (a), (d) and (e) only

Explanation: In artificial hybridization, unisexual female flowers do not require emasculation, but emasculation is necessary for bisexual flowers to prevent self-pollination. After emasculation, flowers are bagged immediately to prevent unwanted pollen contamination. Flowers showing protogyny are avoided since female parts mature first, making control difficult. Correct practices ensure only desired pollen fertilizes stigma, producing true hybrid seeds. Therefore, correct statements are (b), (c), and (e). The correct answer is 3. b, c, and e. Proper emasculation and bagging maintain purity in hybridization programs, enhancing breeding success and trait selection.

1. Single Correct Answer MCQ:

What is the main purpose of emasculation in plant breeding?

a) Enhance pollen production

b) Prevent self-pollination

c) Promote seed germination

d) Increase flower size

Explanation: Emasculation removes anthers from bisexual flowers to prevent self-pollination, ensuring that only selected pollen fertilizes the stigma. It does not increase pollen production, seed germination, or flower size. Correct answer is b) Prevent self-pollination.

2. Single Correct Answer MCQ:

Bagging of flowers is done to:

a) Protect flowers from insects

b) Prevent undesired pollination

c) Accelerate flowering

d) Reduce leaf growth

Explanation: Bagging covers flowers to prevent pollen from unwanted sources contaminating the stigma, ensuring controlled pollination. It does not accelerate flowering or reduce leaf growth. Insect protection is a secondary benefit. Correct answer is b) Prevent undesired pollination.

3. Single Correct Answer MCQ:

Which flowers are suitable for artificial hybridization without emasculation?

a) Bisexual

b) Unisexual female

c) Protandrous

d) Protogynous bisexual

Explanation: Unisexual female flowers lack stamens, so emasculation is unnecessary. Bisexual or protogynous flowers need emasculation to prevent self-pollination. Protandrous flowers have male organs mature first. Correct answer is b) Unisexual female.

4. Single Correct Answer MCQ:

Protogyny in flowers is characterized by:

a) Male organ matures first

b) Female organ matures first

c) Male and female mature simultaneously

d) Flowers are unisexual

Explanation: In protogyny, the female stigma matures before the male anthers, reducing self-pollination but complicating controlled hybridization. Protandry is male first. Correct answer is b) Female organ matures first.

5. Single Correct Answer MCQ:

Which step should follow emasculation in hybridization?

a) Cross pollination

b) Harvesting

c) Leaf trimming

d) Watering

Explanation: After emasculation, cross-pollination is performed immediately to transfer desired pollen onto stigma, followed by bagging to prevent contamination. Harvesting, leaf trimming, or watering are unrelated. Correct answer is a) Cross pollination.

6. Single Correct Answer MCQ:

Why are flowers bagged immediately after cross pollination?

a) Prevent evaporation

b) Protect from wind and insects

c) Maintain stigma receptivity

d) Prevent undesired pollen contamination

Explanation: Bagging prevents contamination by unwanted pollen sources, maintaining purity of hybridization. While protection from insects and environmental factors is secondary, primary purpose is preventing undesired pollen. Correct answer is d) Prevent undesired pollen contamination.

7. Assertion-Reason MCQ:

Assertion (A): Bisexual flowers are emasculated before hybridization.

Reason (R): Emasculation prevents self-pollination and ensures only selected pollen fertilizes stigma.

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: Bisexual flowers contain both male and female organs; emasculation removes anthers to prevent self-fertilization, allowing controlled pollination. Both statements are true, and the reason explains the assertion. Correct answer is a) Both A and R are true, R explains A.

8. Matching Type MCQ:

Match the flower type with its hybridization requirement:

Column I

A) Unisexual female

B) Bisexual

C) Protogynous

D) Protandrous

Column II

1) Emasculation needed

2) Emasculation not needed

3) Avoid selection

4) Emasculation optional

Choices:

A-__ B-__ C-__ D-__

Explanation: Unisexual female: no emasculation (A-2), Bisexual: emasculation required (B-1), Protogynous: avoid selection due to early female maturity (C-3), Protandrous: emasculation optional (D-4). Correct matches: A-2, B-1, C-3, D-4.

9. Fill in the Blanks / Completion MCQ:

The primary goal of bagging flowers in hybridization is __________.

a) Increase photosynthesis

b) Prevent contamination by unwanted pollen

c) Enhance root growth

d) Promote leaf expansion

Explanation: Bagging prevents pollen from unintended sources reaching the stigma, ensuring controlled hybridization and true hybrid seed formation. It does not directly affect photosynthesis, root growth, or leaves. Correct answer is b) Prevent contamination by unwanted pollen.

10. Choose the correct statements MCQ (Statement I & II):

Statement I: Unisexual female flowers do not need emasculation.

Statement II: Bisexual flowers require emasculation to prevent self-pollination.

a) Both I and II are correct

b) Only I is correct

c) Only II is correct

d) Both are incorrect

Explanation: Unisexual female flowers naturally lack stamens, so emasculation is unnecessary. Bisexual flowers contain both male and female organs, requiring emasculation to prevent self-fertilization and ensure controlled hybridization. Both statements are correct. Correct answer is a) Both I and II are correct. 

Chapter: Strategies for Enhancement in Food Production; Subtopic: Apiculture (Bee-keeping)

Keyword Definitions:

• Apiculture: The practice of rearing honeybees for honey, wax, and pollination services.

• Pollination: The transfer of pollen grains from anther to stigma, essential for fertilization in flowering plants.

• Cross-pollination: Pollination between different plants of the same species, enhancing genetic variation and yield.

• Nectar: A sugary fluid secreted by flowers to attract pollinators like bees and butterflies.

• Honeybee species: Common honeybee species include Apis indica, Apis dorsata, and Apis mellifera.

Lead Question - 2022 (Abroad)

Bee-keeping helps to improve the yield of following crops Except ____________.

1. Jowar
2. Sunflower
3. Apple
4. Mustard

Explanation: Bee-keeping enhances the yield of crops that depend on cross-pollination, such as sunflower, apple, and mustard. However, Jowar (sorghum) is mainly self-pollinated and wind-pollinated, not relying on bees for fertilization. Therefore, bee-keeping does not significantly improve its yield. Hence, the correct answer is option 1: Jowar.

1. Which of the following species is commonly used in commercial bee-keeping in India?
1. Apis dorsata
2. Apis indica
3. Apis florae
4. Apis mellifera
Explanation: The Indian honeybee, Apis indica, is commonly used for bee-keeping due to its good honey yield, gentle nature, and adaptability to Indian climate. Other species like Apis dorsata are wild and difficult to domesticate. Hence, option 2 is correct.

2. Which of the following products is not obtained directly from bee-keeping?
1. Honey
2. Wax
3. Propolis
4. Gelatin
Explanation: Bee-keeping yields valuable products such as honey, beeswax, propolis, and royal jelly. Gelatin, however, is derived from animal collagen and has no relation to bee-keeping. Thus, option 4 (Gelatin) is correct.

3. The main role of bees in crop production is to:
1. Protect plants from pests
2. Increase photosynthesis
3. Assist in pollination
4. Improve soil fertility
Explanation: Honeybees act as natural pollinators, transferring pollen between flowers. This enhances fruit and seed formation, especially in cross-pollinated crops. Their activity greatly increases crop yield and quality. Hence, option 3 is correct.

4. The major component of honey is:
1. Maltose
2. Sucrose
3. Glucose and Fructose
4. Lactose
Explanation: Honey mainly contains glucose and fructose derived from flower nectar. These simple sugars provide quick energy and natural sweetness. It also contains vitamins, enzymes, and antioxidants. Hence, option 3 is correct.

5. Which of the following crops benefit the most from bee pollination?
1. Maize
2. Mustard
3. Wheat
4. Rice
Explanation: Mustard is a cross-pollinated crop and depends on insects like honeybees for successful fertilization. Maize, wheat, and rice are wind-pollinated and do not rely on bees. Therefore, option 2 is correct.

6. Bee-keeping contributes to which of the following agricultural goals?
1. Increasing soil fertility
2. Enhancing crop yield through pollination
3. Reducing pesticide use
4. Improving irrigation efficiency
Explanation: Bee-keeping increases crop productivity by facilitating pollination. Bees enhance fertilization efficiency and fruit set in many crops, resulting in higher yield and quality. Hence, option 2 is correct.

7. Assertion-Reason Question:
Assertion (A): Bee-keeping is essential for cross-pollinated crops.
Reason (R): Bees enhance gene flow between different plants by carrying pollen grains.
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: Bees serve as natural agents of pollination, transferring pollen from one flower to another, promoting genetic recombination and fruit setting. Thus, both statements are true, and the reason correctly explains the assertion. Hence, option 1 is correct.

8. Matching Type Question:
Match the following:
A. Apis dorsata — (i) Indian honeybee
B. Apis indica — (ii) Rock bee
C. Apis mellifera — (iii) Italian bee
D. Apis florae — (iv) Little bee
1. A-(ii), B-(i), C-(iii), D-(iv)
2. A-(i), B-(ii), C-(iv), D-(iii)
3. A-(iv), B-(ii), C-(i), D-(iii)
4. A-(iii), B-(ii), C-(iv), D-(i)
Explanation: Apis dorsata (Rock bee) is wild and large, Apis indica (Indian bee) is domesticated, Apis mellifera (Italian bee) gives high honey yield, and Apis florae (Little bee) produces less honey. Hence, option 1 is correct.

9. Fill in the Blanks / Completion Question:
The substance collected by bees from flower nectar and converted into honey is called ______.
1. Resin
2. Nectar
3. Pollen
4. Propolis
Explanation: Honeybees collect nectar from flowers, which they enzymatically convert into honey and store in honeycombs. The evaporation of water from nectar gives thick, sugary honey rich in glucose and fructose. Hence, the correct answer is option 2: Nectar.

10. Choose the Correct Statements (Statement I & Statement II):
Statement I: Bee-keeping provides pollination services and income from honey.
Statement II: Bee-keeping has no role in improving crop yield.
1. Both statements are true.
2. Both statements are false.
3. Statement I is true and Statement II is false.
4. Statement I is false and Statement II is true.
Explanation: Bee-keeping serves dual purposes—producing honey and enhancing pollination. Pollination by bees improves fruit and seed yield in many crops. Therefore, Statement I is true while Statement II is false. Hence, option 3 is correct.

Topic: Revolutions in Agriculture; Subtopic: Blue Revolution

Keyword Definitions:

• Blue Revolution: Rapid increase in fish production through aquaculture, improving nutrition and employment.

• Aquaculture: The breeding, rearing, and harvesting of fish, shellfish, and aquatic plants.

• Fishery Industry: Commercial industry focused on capturing, farming, and selling fish and seafood.

• Crop Plants: Plants cultivated for food, fiber, or other agricultural products.

• Honey Production: Commercial production of honey and its derivatives from bees.

• Water Reservoirs: Man-made lakes storing water for irrigation, drinking, or energy generation.

Lead Question - 2022 (Abroad)
The term 'Blue Revolution' is related with:
1. Various crop plants and their by products
2. Development of water reservoirs
3. Honey and its by products
4. Fishery industry
Explanation: The Blue Revolution refers to the rapid development of the fishery industry, particularly aquaculture, to increase fish production and supply. It aims to enhance food security, nutrition, and employment. Unlike the Green Revolution, which focused on crops, or honey production and water reservoirs, the Blue Revolution specifically targets improvement of fish farming techniques, sustainable harvesting, and expansion of aquaculture infrastructure to meet growing demand for protein-rich food in developing and developed countries.

1. Single Correct Answer Type:
Which of the following is a major goal of the Blue Revolution?
1. Increase crop yield
2. Enhance fish production
3. Promote honey production
4. Build dams
Explanation: The main goal of the Blue Revolution is to enhance fish production through aquaculture and improved fisheries management. This includes breeding programs, sustainable harvesting, and infrastructure development to increase fish supply. Unlike crop or honey production, or water reservoir construction, the Blue Revolution focuses on aquatic protein sources, contributing to nutrition, employment, and export potential in coastal and inland regions.

2. Single Correct Answer Type:
Which method is commonly used in the Blue Revolution?
1. Selective crop breeding
2. Fish farming in ponds and tanks
3. Beekeeping techniques
4. Building irrigation canals
Explanation: The Blue Revolution primarily uses fish farming in ponds and tanks to increase production efficiently. Aquaculture methods include controlled breeding, feeding, and habitat management. Unlike crop breeding, beekeeping, or irrigation construction, fish farming ensures sustainable supply of aquatic protein, reduces pressure on wild stocks, and promotes economic growth. Advanced technologies like aeration and water quality control are also implemented.

3. Single Correct Answer Type:
The Blue Revolution is comparable to which other agricultural revolution in terms of productivity focus?
1. White Revolution
2. Green Revolution
3. Yellow Revolution
4. Brown Revolution
Explanation: The Green Revolution and Blue Revolution are comparable in their focus on productivity. While the Green Revolution increased crop yields using high-yielding varieties and fertilizers, the Blue Revolution enhanced fish production through aquaculture innovations. Both revolutions aimed to ensure food security, improve nutrition, and support economic growth. However, the Blue Revolution specifically targets aquatic food resources rather than plant-based agriculture.

4. Single Correct Answer Type:
Which sector benefits directly from the Blue Revolution?
1. Apiculture
2. Agriculture
3. Fisheries
4. Forestry
Explanation: The Fisheries sector benefits directly from the Blue Revolution. Increased fish production through aquaculture and improved harvesting techniques boosts supply, income, and employment in coastal and inland regions. While agriculture, forestry, and apiculture are important for food production, the Blue Revolution specifically targets fisheries to provide protein-rich food, support exports, and develop rural economies.

5. Single Correct Answer Type:
Which nutritional benefit is primarily associated with the Blue Revolution?
1. Increased carbohydrate intake
2. Increased protein intake
3. Increased fiber intake
4. Increased vitamin C intake
Explanation: The Blue Revolution increases availability of fish, which are rich sources of high-quality protein and essential fatty acids. Enhanced fish consumption improves nutrition, especially in regions with protein deficiency. Unlike crop-based revolutions, which may focus on carbohydrates, or fruits for vitamins, the Blue Revolution addresses protein security, contributing to balanced diets and supporting growth, health, and cognitive development.

6. Single Correct Answer Type:
Which technology is integral to the Blue Revolution?
1. Hybrid crop seeds
2. Hatchery and feed management
3. Honey bee colonies
4. Drip irrigation
Explanation: Hatchery and feed management are essential technologies in the Blue Revolution, enabling controlled breeding, larval rearing, and optimal feeding for fish. This ensures higher survival rates and rapid growth. Unlike hybrid crops, beekeeping, or irrigation systems, these techniques specifically enhance aquaculture productivity, contributing to increased fish supply, economic benefits, and sustainable food resources.

7. Assertion-Reason Type:
Assertion (A): The Blue Revolution led to increased employment in coastal areas.
Reason (R): Aquaculture development requires labor for pond management, harvesting, and processing.
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. The Blue Revolution increased employment as aquaculture expansion required skilled and unskilled labor for pond preparation, feeding, harvesting, and processing of fish. The reason explains the assertion because the growth in fisheries directly created jobs and boosted income in coastal and inland communities.

8. Matching Type:
Match the revolution with its focus:
A. Green Revolution → (i) Fish production
B. White Revolution → (ii) Milk production
C. Blue Revolution → (iii) Crop yield
1. A-(iii), B-(ii), C-(i)
2. A-(ii), B-(iii), C-(i)
3. A-(i), B-(iii), C-(ii)
4. A-(iii), B-(i), C-(ii)
Explanation: Correct matching is A-(iii), B-(ii), C-(i). Green Revolution increased crop yields, White Revolution enhanced milk production, and Blue Revolution focused on fishery development. Each revolution targeted a specific sector to improve food security, nutrition, and economic growth. The Blue Revolution is unique as it involves aquaculture and fisheries rather than terrestrial agriculture.

9. Fill in the Blanks Type:
The Blue Revolution primarily aims to increase _______ through aquaculture.
1. Crop yield
2. Milk production
3. Fish production
4. Honey output
Explanation: The correct answer is fish production. The Blue Revolution enhances aquaculture practices, including pond management, hatchery development, and feed optimization, to boost fish supply. Unlike crops, milk, or honey, this revolution specifically targets aquatic food sources to improve protein intake, create employment, and support rural economies, contributing significantly to national nutrition and export potential.

10. Choose the Correct Statements Type:
Which of the following statements about the Blue Revolution are correct?
1. It focuses on crop productivity
2. It increases fish production through aquaculture
3. It improves employment opportunities in fisheries
4. It is synonymous with milk production
Explanation: Correct statements are 2 and 3. The Blue Revolution focuses on increasing fish production via aquaculture and simultaneously improves employment opportunities in fisheries. It is distinct from crop-focused or milk-related revolutions. By enhancing

Topic: Crop Improvement
Subtopic: Biofortification

Keyword Definitions:
• Biofortification: Breeding crops to increase their nutritional value including vitamins, minerals, proteins, and healthier fats.
• Bio-remediation: Use of living organisms to remove pollutants from the environment.
• Bio-accumulation: Gradual accumulation of substances in an organism.
• Bio-magnification: Increase in concentration of toxins in higher trophic levels.
• Genetic Engineering: Manipulation of an organism's DNA to improve traits.
• Micronutrients: Essential nutrients required in small amounts for growth and development.
• Macronutrients: Nutrients required in large amounts such as proteins, carbohydrates, and fats.
• Crop Improvement: Techniques used to enhance yield, nutrition, and resistance.
• Phenotype: Observable traits of an organism resulting from genes and environment.
• Allele: A variant form of a gene that determines specific traits.

Lead Question (2022):
Breeding crops with higher levels of vitamins and minerals or higher proteins and healthier fats is called:
(1) Bio – remediation
(2) Bio – fortification
(3) Bio – accumulation
(4) Bio – magnification

Explanation: The correct answer is (2). Biofortification is the process of enhancing the nutritional quality of crops through conventional breeding or genetic engineering. It increases vitamins, minerals, proteins, and beneficial fats in staple crops, helping to combat malnutrition and improve human health globally.

Guessed MCQs:

1. Single Correct Answer:
Which technique improves crop nutrition by adding essential minerals and vitamins?
(a) Biofortification
(b) Bioremediation
(c) Bioaccumulation
(d) Biomagnification
Explanation: The correct answer is (a). Biofortification enhances the nutrient content of crops, increasing vitamins and minerals to improve health, particularly in populations relying on staple foods with low natural micronutrients.

2. Single Correct Answer:
Which process uses microorganisms to clean pollutants from soil and water?
(a) Bioremediation
(b) Biofortification
(c) Bioaccumulation
(d) Genetic engineering
Explanation: The correct answer is (a). Bioremediation uses bacteria, fungi, or plants to detoxify contaminated environments, removing chemicals and pollutants effectively while being environmentally friendly and sustainable.

3. Assertion-Reason MCQ:
Assertion (A): Biofortification improves crop nutrient content.
Reason (R): It can be achieved by conventional breeding and genetic engineering.
(a) Both A and R are correct, R explains A
(b) Both A and R are correct, R does not explain A
(c) A is correct, R is false
(d) A is false, R is true
Explanation: The correct answer is (a). Biofortification increases vitamins, minerals, and proteins in crops, and this can be achieved by selective breeding or genetic modification to develop nutritionally enhanced varieties.

4. Matching Type MCQ:
Match the terms with their definitions:
A. Biofortification – (i) Increase nutrient content in crops
B. Bioremediation – (ii) Clean pollutants using living organisms
C. Biomagnification – (iii) Toxins increase in higher trophic levels
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). Biofortification increases nutrients, bioremediation removes pollutants with organisms, and biomagnification leads to toxin accumulation in predators at higher trophic levels.

5. Single Correct Answer:
Which of the following crops is commonly biofortified for vitamin A?
(a) Golden rice
(b) Wheat
(c) Soybean
(d) Corn
Explanation: The correct answer is (a). Golden rice is genetically modified to produce beta-carotene, a precursor of vitamin A, helping to prevent vitamin A deficiency in populations dependent on rice as a staple food.

6. Single Correct Answer:
Which biofortified crop is enhanced with iron to reduce anemia?
(a) Pearl millet
(b) Potato
(c) Banana
(d) Tomato
Explanation: The correct answer is (a). Iron-biofortified pearl millet is developed to address iron deficiency and anemia in regions where millet is a dietary staple, improving hemoglobin levels and overall health.

7. Fill in the Blanks:
__________ crops are developed to contain higher nutrient content such as vitamins and minerals.
(a) Biofortified
(b) Bioremediated
(c) Bioaccumulated
(d) Biomagnified
Explanation: The correct answer is (a). Biofortified crops are bred or engineered to enhance nutritional value, providing essential micronutrients to combat malnutrition in regions dependent on staple foods.

8. Single Correct Answer:
Which nutrient is commonly enhanced in biofortified sweet potatoes?
(a) Beta-carotene (Vitamin A)
(b) Lead
(c) Mercury
(d) Caffeine
Explanation: The correct answer is (a). Biofortified sweet potatoes are rich in beta-carotene, a precursor to vitamin A, helping prevent deficiency-related blindness and supporting overall health in vulnerable populations.

9. Single Correct Answer:
The main aim of biofortification is:
(a) Enhance nutritional quality of crops
(b) Increase pesticide resistance
(c) Remove soil toxins
(d) Increase plant height
Explanation: The correct answer is (a). Biofortification aims to improve the vitamin, mineral, protein, and healthy fat content of staple crops, thereby providing essential nutrients to humans and improving public health.

10. Choose the correct statements:
(a) Biofortification increases nutrient content in crops.
(b) Bioremediation removes pollutants using living organisms.
(c) Biomagnification increases toxin concentration in food chains.
(d) Bioaccumulation reduces nutrient content in crops.
Options:
1. a, b, c only
2. a and d only
3. b and c only
4. All statements
Explanation: The correct answer is (1). Biofortification enhances nutrients, bioremediation detoxifies the environment, and biomagnification increases toxin concentration. Bioaccumulation does not reduce nutrients; it refers to substance accumulation in organisms.

Topic : Assisted Reproductive Technologies
Subtopic : MOET Technique

Keyword Definitions :

• MOET : Multiple Ovulation Embryo Transfer is a technique to increase the reproductive potential of animals by inducing superovulation and embryo transfer.

• Superovulation : The release of multiple eggs from ovaries induced by hormone treatment.

• Artificial Insemination : A process of introducing sperm into the female reproductive tract without natural mating.

• Surrogate mother : A female animal receiving and carrying embryos of another female until birth.

• Embryo transfer : Implanting fertilized embryos into surrogate mothers for development.

Lead Question - 2021

Which of the following is not a step in Multiple Ovulation Embryo Transfer Technology (MOET)?
(1) Cow yields about 6-8 eggs at a time
(2) Cow is fertilized by artificial insemination
(3) Fertilized eggs are transferred to surrogate mothers at 8-32 cell stage
(4) Cow is administered hormone having LH like activity for super ovulation

Explanation : The incorrect step is that the cow yields 6-8 eggs at a time. Normally, MOET produces 6-8 embryos after superovulation and fertilization, not eggs. Correct steps include superovulation by hormones, artificial insemination, and embryo transfer at 8-32 cell stage into surrogate mothers. Hence, option (1) is correct.

1) Superovulation in cattle is usually induced by administration of
(1) FSH
(2) LH
(3) Prolactin
(4) Oxytocin

Explanation : FSH is administered for superovulation in cattle, causing multiple follicles to mature and ovulate. LH induces only one ovulation, oxytocin acts during parturition, and prolactin stimulates milk secretion. Thus, option (1) is the correct answer.

2) The embryos in MOET are transferred into
(1) Test-tube
(2) Surrogate mothers
(3) Artificial uterus
(4) Host sperm cells

Explanation : In MOET, fertilized embryos at the 8-32 cell stage are transferred into surrogate mothers for normal development. Other options are not part of the reproductive process. Hence, option (2) is correct.

3) Artificial insemination involves
(1) Transfer of embryo
(2) Introduction of sperm into the female tract
(3) Transfer of zygote
(4) Induction of ovulation

Explanation : Artificial insemination is the direct introduction of sperm into the female reproductive tract to achieve fertilization without mating. It does not involve embryo transfer, zygote placement, or ovulation induction. Hence, option (2) is correct.

4) Embryo transfer in MOET is done at
(1) Zygote stage
(2) 2-cell stage
(3) 8-32 cell stage
(4) Blastula stage

Explanation : In MOET, embryos are transferred at the 8-32 cell stage into surrogate mothers, ensuring better chances of implantation and survival. Zygote or 2-cell stages are too early, and blastula stage is too late. Hence, option (3) is correct.

5) Which of the following is a benefit of MOET?
(1) Higher milk production
(2) Rapid multiplication of elite animals
(3) Induction of artificial puberty
(4) Reducing gestation period

Explanation : MOET is primarily used to rapidly multiply genetically superior animals by producing more offspring through embryo transfer. It is not directly related to milk yield, puberty induction, or gestation. Hence, option (2) is correct.

6) Which hormone mimics LH activity in MOET?
(1) FSH
(2) hCG
(3) Progesterone
(4) Estrogen

Explanation : In MOET, human chorionic gonadotropin (hCG) is administered as it mimics LH activity, inducing ovulation. FSH induces follicle growth, progesterone maintains pregnancy, and estrogen supports female reproductive physiology. Hence, option (2) is correct.

7) Assertion (A): MOET is used in animal breeding for rapid herd improvement.
Reason (R): MOET allows transfer of fertilized eggs from genetically inferior to superior animals.
(1) Both (A) and (R) are true, but (R) is not the correct explanation of (A)
(2) (A) is true, but (R) is false
(3) Both (A) and (R) are false
(4) Both (A) and (R) are true, and (R) is the correct explanation of (A)

Explanation : MOET transfers embryos from superior animals to surrogate mothers for genetic improvement. The reason given is false because embryos are not taken from inferior animals. Thus, option (2) is correct.

8) Match the following related to MOET:
A. FSH injection – (i) Superovulation
B. hCG – (ii) Ovulation induction
C. Artificial insemination – (iii) Fertilization
D. Embryo transfer – (iv) Surrogate mother implantation
(1) A-(iii), B-(iv), C-(i), D-(ii)
(2) A-(i), B-(ii), C-(iii), D-(iv)
(3) A-(ii), B-(i), C-(iv), D-(iii)
(4) A-(iv), B-(iii), C-(ii), D-(i)

Explanation : FSH injection induces superovulation, hCG induces ovulation, artificial insemination achieves fertilization, and embryo transfer implants embryos in surrogate mothers. Hence, the correct match is option (2).

9) Fill in the blanks: In MOET, embryos are transferred at the _______ stage into surrogate mothers.
(1) Zygote
(2) 2-cell
(3) 8-32 cell
(4) Blastula

Explanation : The correct stage for embryo transfer in MOET is the 8-32 cell stage. This ensures successful implantation and development. Other stages either fail to implant effectively or are too late for transfer. Hence, option (3) is correct.

10) Choose the correct statements:
A. MOET increases offspring from superior cows.
B. Surrogate mothers carry embryos from elite cows.
C. Embryos are transferred at 8-32 cell stage.
D. MOET eliminates the need for artificial insemination.
(1) A, B, and C
(2) A and D
(3) B, C, and D
(4) A, B, C, and D

Explanation : Statements A, B, and C are correct as MOET enhances multiplication of elite animals, uses surrogates, and transfers embryos at the 8-32 cell stage. Statement D is false since artificial insemination is an essential step in MOET. Hence, option (1) is correct.

Subtopic: Biofortification

• Biofortification: The process of increasing nutrient content in crops through breeding or biotechnology to combat malnutrition.

• Micronutrients: Essential vitamins and minerals required in small quantities for human health, e.g., iron, zinc, vitamin A.

• Vitamin content: Amount of vitamins present in edible parts of crops, targeted in biofortification.

• Protein content: Quantity of protein in crops, generally improved by conventional breeding, not the main aim of biofortification.

• Disease resistance: Ability of crops to withstand pathogens, not a primary target of biofortification.

• Crop improvement: Methods like genetic modification or selective breeding to enhance yield, nutrition, or stress resistance.

• Malnutrition: Nutrient deficiency in populations that biofortified crops aim to alleviate.

• Breeding: Selection of parent plants with desirable traits to produce nutrient-rich varieties.

• Genetic engineering: Biotechnology method used to enhance vitamin or mineral content in crops.

• Iron-biofortified rice: Example of biofortified crop designed to reduce iron deficiency anemia.

• Zinc-biofortified wheat: Example of crop enhanced for essential micronutrients.

Lead Question - 2021

Which of the following is not an objective of Biofortification in crops?

(1) Improve resistance to diseases
(2) Improve vitamin content
(3) Improve micronutrient and mineral content
(4) Improve protein content

Explanation: Biofortification aims to enhance vitamin, mineral, and micronutrient content in crops to combat malnutrition. Improving disease resistance or protein content is not the primary objective. Biofortified crops target nutritional quality rather than yield or disease traits. Answer: Improve resistance to diseases.

1. Single Correct Answer MCQ: The main goal of biofortification is to:
Options:
A. Increase crop yield
B. Enhance micronutrient content
C. Improve disease resistance
D. Reduce water usage

Explanation: Biofortification primarily enhances essential micronutrients like iron, zinc, and vitamins in crops, aiming to reduce malnutrition. Yield, disease resistance, or water usage are secondary traits. Answer: Enhance micronutrient content.

2. Single Correct Answer MCQ: Which micronutrient is commonly increased in rice by biofortification?
Options:
A. Calcium
B. Iron
C. Magnesium
D. Phosphorus

Explanation: Iron is commonly increased in rice through biofortification to combat iron-deficiency anemia in populations relying on rice as staple food. Answer: Iron.

3. Single Correct Answer MCQ: Biofortified wheat is enriched with:
Options:
A. Vitamin C
B. Zinc
C. Omega-3
D. Fiber

Explanation: Zinc-biofortified wheat helps reduce zinc deficiency, supporting immune and growth functions. Other nutrients like vitamin C, omega-3, or fiber are not the primary targets. Answer: Zinc.

4. Single Correct Answer MCQ: Protein content in biofortified crops:
Options:
A. Is the main target
B. Is secondary or indirect
C. Cannot be enhanced
D. Is ignored

Explanation: Biofortification focuses on vitamins and minerals; protein content may improve indirectly in some varieties but is not the primary target. Conventional breeding is used for protein enhancement. Answer: Is secondary or indirect.

5. Single Correct Answer MCQ: Disease resistance in crops is enhanced mainly by:
Options:
A. Biofortification
B. Conventional breeding and genetic engineering
C. Fertilizers
D. Irrigation

Explanation: Disease resistance is primarily improved by conventional breeding or genetic modification, not biofortification, which targets nutrient enhancement. Answer: Conventional breeding and genetic engineering.

6. Single Correct Answer MCQ: Golden rice is biofortified for:
Options:
A. Vitamin A
B. Vitamin B12
C. Vitamin C
D. Iron

Explanation: Golden rice is genetically modified to produce beta-carotene, a precursor of vitamin A, helping prevent vitamin A deficiency. Answer: Vitamin A.

7. Assertion-Reason MCQ:
Assertion (A): Biofortification improves crop nutritional quality.
Reason (R): It increases vitamin and mineral content in edible parts.
Options:
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: Biofortification improves nutritional quality by increasing vitamins and minerals. Reason accurately explains the assertion. Answer: Both A and R true, R correct explanation.

8. Matching Type MCQ:
Column I: 1. Iron-biofortified rice 2. Zinc-biofortified wheat 3. Golden rice 4. Protein-enriched maize
Column II: A. Vitamin A B. Zinc C. Iron D. Protein
Options:
A. 1-C, 2-B, 3-A, 4-D
B. 1-A, 2-B, 3-C, 4-D
C. 1-B, 2-C, 3-A, 4-D
D. 1-C, 2-A, 3-B, 4-D

Explanation: Iron-biofortified rice increases iron, zinc-biofortified wheat enhances zinc, Golden rice provides vitamin A, and protein-enriched maize improves protein. Answer: 1-C, 2-B, 3-A, 4-D.

9. Fill in the Blank MCQ: Biofortification primarily aims to increase ______ in crops.
Options:
A. Yield
B. Vitamins and minerals
C. Water content
D. Pest resistance

Explanation: Biofortification targets increased vitamins and minerals in crops to combat malnutrition. Yield and pest resistance are secondary traits. Answer: Vitamins and minerals.

10. Choose the correct statements MCQ:
(a) Biofortification improves micronutrient content.
(b) It enhances vitamin content.
(c) It is mainly for improving disease resistance.
(d) Protein content may be enhanced indirectly.
Options:
1. (a), (b), (d) only
2. (a) and (c) only
3. (b) and (c) only
4. All of the above

Explanation: Biofortification targets micronutrient and vitamin content. Protein may improve indirectly. Disease resistance is not a main objective. Answer: (a), (b), (d) only.

Topic: Inbreeding and Genetic Effects
Subtopic: Inbreeding Depression

Keyword Definitions:

• Inbreeding: Mating between closely related individuals in a population.

• Inbreeding depression: Reduced biological fitness due to increased homozygosity from inbreeding.

• Fertility: Ability to produce offspring.

• Productivity: Yield of animals in terms of milk, eggs, or growth.

• Progeny: Offspring produced by breeding.

• Genetic diversity: Variation of alleles within a population.

• Close breeding: Mating among individuals sharing recent common ancestors.

• Homozygosity: Presence of identical alleles at a gene locus.

• Heterozygosity: Presence of different alleles at a gene locus.

• Animal breeding: Selection and mating of animals to improve desired traits.

• Motility: Ability of organisms or cells to move.

Lead Question - 2020 (COVID Reexam)

Inbreeding depression is:

1. Reduced motility and immunity due to close inbreeding
2. Decreased productivity due to mating of superior male and inferior female
3. Decrease in body mass of progeny due to continued close inbreeding
4. Reduced fertility and productivity due to continued close inbreeding

Explanation: The correct answer is option 4. Inbreeding depression results from continued close inbreeding, leading to increased homozygosity, expression of deleterious recessive alleles, reduced fertility, and lower productivity in animals. It negatively affects growth, survival, and reproduction, making it a critical factor in animal breeding programs.

1. Chapter: Genetics and Animal Breeding
Topic: Inbreeding and Genetic Effects
Subtopic: Inbreeding Depression

Keyword Definitions:

• Inbreeding: Mating of closely related individuals.

• Inbreeding depression: Reduced fitness due to homozygosity.

• Fertility: Reproductive capability.

• Productivity: Yield of milk, eggs, or growth.

• Progeny: Offspring of breeding.

• Genetic diversity: Allelic variation within a population.

• Close breeding: Mating among recent relatives.

• Homozygosity: Identical alleles at a locus.

• Heterozygosity: Different alleles at a locus.

• Animal breeding: Selection to improve traits.

• Motility: Ability to move.

Q1. Single Correct Answer: What is the main cause of inbreeding depression?
a) Crossbreeding
b) Increased homozygosity
c) Outbreeding
d) Environmental stress

Explanation: The correct answer is increased homozygosity. Inbreeding increases homozygosity, causing expression of deleterious recessive alleles, reducing fertility, survival, and productivity. Crossbreeding or outbreeding increases heterozygosity. Environmental stress may affect productivity but is not the main cause of inbreeding depression, making option (b) correct.

Q2. Single Correct Answer: Inbreeding depression primarily affects:
a) Fertility and productivity
b) Coat color
c) Motility only
d) External morphology

Explanation: Inbreeding depression mainly reduces fertility and productivity in animals due to expression of harmful recessive genes. Coat color and external morphology may remain unaffected. Motility might be affected indirectly. Option (a) correctly identifies the primary traits impacted by inbreeding depression in breeding populations.

Q3. Single Correct Answer: Which term refers to the offspring of closely related individuals?
a) Heterozygotes
b) Progeny
c) Crossbreeds
d) Mutants

Explanation: The correct answer is progeny. Progeny are the offspring resulting from mating, including inbreeding. Heterozygotes have different alleles, crossbreeds result from unrelated parents, and mutants have genetic changes. Inbreeding increases homozygosity in progeny, leading to inbreeding depression, making option (b) correct.

Q4. Single Correct Answer: Continuous inbreeding can reduce:
a) Fertility
b) Productivity
c) Survival
d) All of the above

Explanation: The correct answer is all of the above. Continuous inbreeding reduces fertility, productivity, and survival by increasing homozygosity and expression of harmful recessive alleles. This reduces overall biological fitness in animal populations. Therefore, option (d) is correct, emphasizing the negative impact of inbreeding depression.

Q5. Single Correct Answer: Which practice helps prevent inbreeding depression?
a) Close breeding
b) Outcrossing
c) Self-fertilization
d) Line breeding

Explanation: The correct answer is outcrossing. Outcrossing involves mating unrelated individuals, increasing heterozygosity and genetic diversity, which prevents inbreeding depression. Close breeding and line breeding increase homozygosity, while self-fertilization promotes inbreeding. Outcrossing maintains productivity, fertility, and survival in breeding populations.

Q6. Single Correct Answer: Homozygosity leads to:
a) Expression of deleterious alleles
b) Increased fertility
c) Improved productivity
d) Greater heterozygosity

Explanation: The correct answer is expression of deleterious alleles. Increased homozygosity due to inbreeding exposes harmful recessive alleles, reducing fertility and productivity. Heterozygosity provides genetic variation and fitness. Therefore, option (a) explains the genetic mechanism underlying inbreeding depression.

Q7. Assertion-Reason:
Assertion (A): Inbreeding depression decreases productivity.
Reason (R): Inbreeding increases homozygosity, expressing harmful recessive genes.

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: Both the assertion and reason are true, and the reason correctly explains the assertion. Inbreeding increases homozygosity, leading to harmful recessive allele expression, which decreases fertility, productivity, and survival. Therefore, option (a) is correct.

Q8. Matching Type: Match breeding practices with outcomes:
Column - I: a) Inbreeding, b) Outcrossing, c) Line breeding
Column - II: i) Reduces genetic diversity, ii) Maintains heterozygosity, iii) Selective close breeding

Options:
1. a-i, b-ii, c-iii
2. a-ii, b-i, c-iii
3. a-iii, b-ii, c-i
4. a-i, b-iii, c-ii

Explanation: Correct match is a-i, b-ii, c-iii. Inbreeding reduces genetic diversity, outcrossing maintains heterozygosity, and line breeding is selective mating of close relatives. This demonstrates the genetic impact of different breeding practices. Option (1) is correct.

Q9. Fill in the Blanks: ________ is reduced due to inbreeding depression.
a) Fertility
b) Heterozygosity
c) Gene mutation
d) Environmental adaptation

Explanation: Fertility is reduced due to inbreeding depression. Close inbreeding increases homozygosity, expressing deleterious alleles, and lowering reproductive success. Heterozygosity decreases, but the main observable effect is reduced fertility and productivity in progeny. Therefore, option (a) is correct.

Q10. Choose the correct statements:
1) Inbreeding depression affects fertility and productivity.
2) Outcrossing increases genetic diversity.
3) Continuous inbreeding is beneficial for all traits.
4) Homozygosity can expose harmful alleles.

a) 1, 2, 4
b) 1, 3, 4
c) 2, 3, 4
d) All are correct

Explanation: Statements 1, 2, and 4 are correct. Inbreeding depression reduces fertility and productivity, outcrossing increases genetic diversity, and homozygosity exposes harmful alleles. Continuous inbreeding is harmful, not beneficial. Therefore, option (a) is correct, emphasizing proper breeding strategies to maintain fitness.

Topic: Animal Improvement Methods
Subtopic: Crossbreeding in Sheep

• Crossbreeding: Mating of two genetically different individuals from distinct breeds to produce offspring with desired traits.

• Inbreeding: Mating of closely related individuals to preserve desired traits but may increase genetic disorders.

• Out crossing: Mating unrelated animals of the same breed to increase vigor.

• Mutational breeding: Inducing mutations artificially to produce new traits in animals or plants.

• Bikaneri ewe: Sheep breed known for its wool quality, used in breeding programs.

• Marino ram: Sheep breed famous for fine wool production, often used in crossbreeding.

• Hisardale sheep: Hybrid breed developed for improved wool and body characteristics.

• Animal improvement: Methods employed to enhance productivity, yield, or adaptability of livestock.

• Hybrid vigor: Increased performance of crossbred animals compared to parents.

• Breeding program: Planned mating of selected animals to achieve specific goals.

• Genetic traits: Heritable characteristics that can be passed to offspring.

Lead Question (2020): By which method was a new breed ‘Hisardale’ of sheep formed by using Bikaneri ewes and Marino rams?
Options:
1. Cross breeding
2. Inbreeding
3. Out crossing
4. Mutational breeding

Explanation: Correct answer is 1. Hisardale sheep was developed by mating Bikaneri ewes with Marino rams through crossbreeding. This method combined superior traits of both parent breeds, resulting in hybrid offspring with enhanced wool quality and body characteristics, demonstrating the principle of genetic improvement through planned crossbreeding.

1. Single Correct Answer MCQ:
Which method increases hybrid vigor in livestock?
Options:
a. Crossbreeding
b. Inbreeding
c. Out crossing within same breed
d. Mutation induction

Explanation: Correct answer is a. Crossbreeding combines traits from two different breeds, leading to hybrid vigor, which improves growth, fertility, and productivity. It is widely used in animal husbandry for livestock improvement.

2. Single Correct Answer MCQ:
In which method are genetically close animals mated to maintain purity?
Options:
a. Crossbreeding
b. Inbreeding
c. Out crossing
d. Hybridization

Explanation: Correct answer is b. Inbreeding involves mating closely related individuals to retain specific traits. While it preserves breed characteristics, excessive inbreeding may increase genetic disorders.

3. Single Correct Answer MCQ:
Marino sheep are primarily used for:
Options:
a. Meat production
b. Wool quality improvement
c. Disease resistance
d. Milk production

Explanation: Correct answer is b. Marino rams are renowned for fine wool. Crossing them with local breeds enhances wool quality in hybrid sheep like Hisardale, demonstrating the use of superior genetic traits for improvement.

4. Single Correct Answer MCQ:
Out crossing involves:
Options:
a. Mating unrelated individuals of same breed
b. Mating individuals of different species
c. Mating closely related individuals
d. Inducing mutations artificially

Explanation: Correct answer is a. Out crossing enhances genetic diversity within a breed by mating unrelated individuals, reducing inbreeding depression while maintaining breed purity.

5. Single Correct Answer MCQ:
Mutational breeding aims to:
Options:
a. Cross two breeds
b. Increase mutation frequency artificially
c. Mate unrelated individuals
d. Preserve breed purity

Explanation: Correct answer is b. Mutational breeding induces mutations in animals or plants artificially to create new traits, providing a tool for genetic improvement beyond traditional breeding methods.

6. Single Correct Answer MCQ:
Hisardale sheep is primarily an outcome of:
Options:
a. Natural selection
b. Crossbreeding
c. Inbreeding
d. Random mating

Explanation: Correct answer is b. Planned crossbreeding between Bikaneri ewes and Marino rams produced Hisardale sheep, combining desired traits for wool quality and adaptability, exemplifying systematic genetic improvement.

7. Assertion-Reason MCQ:
Assertion (A): Crossbreeding improves wool quality in sheep.
Reason (R): It combines superior traits from two different breeds.
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. Crossbreeding Bikaneri ewes with Marino rams produces Hisardale sheep with enhanced wool quality, showing that combining superior traits explains improved characteristics.

8. Matching Type MCQ:
Match the breeds with their contributions:
(a) Bikaneri ewe - (i) Fine wool
(b) Marino ram - (ii) Large body size
(c) Hisardale - (iii) Hybrid breed
Options:
1. a-i, b-ii, c-iii
2. a-ii, b-i, c-iii
3. a-i, b-iii, c-ii
4. a-iii, b-i, c-ii

Explanation: Correct answer is 2. Bikaneri ewe provides adaptability and body traits, Marino ram contributes fine wool, and their cross produces Hisardale as a hybrid breed combining desirable traits.

9. Fill in the Blanks MCQ:
Hybrid vigor obtained in Hisardale sheep is due to ________.
Options:
a. Inbreeding
b. Crossbreeding
c. Mutational breeding
d. Out crossing within breed

Explanation: Correct answer is b. Crossbreeding Bikaneri ewes with Marino rams generates hybrid vigor, improving traits like growth rate, wool quality, and adaptability in Hisardale sheep.

10. Choose the correct statements MCQ:
Select the correct statements:
i. Hisardale sheep was developed by crossbreeding
ii. Crossbreeding combines traits from different breeds
iii. Inbreeding produces hybrid vigor
iv. Marino rams provide fine wool
Options:
1. i, ii, iv
2. i, iii, iv
3. ii, iii
4. All of the above

Explanation: Correct answer is 1. Hisardale sheep resulted from crossbreeding, which combines traits from Bikaneri ewes and Marino rams. Marino rams contribute fine wool, while inbreeding does not produce hybrid vigor, making statements i, ii, and iv correct.

Topic: Inbreeding and Genetic Improvement

Subtopic: Effects of Inbreeding

Keyword Definitions:

• Inbreeding: Mating between closely related individuals to preserve desired traits

• Homozygosity: Presence of identical alleles at a gene locus

• Pureline: Genetically uniform population

• Recessive Genes: Genes expressed only in homozygous state

• Fertility: Ability to produce offspring

• Productivity: Overall performance in traits like growth, milk, or eggs

• Genetic Improvement: Enhancement of desirable traits in a population

Lead Question - 2019

Select the incorrect statement:

(1) Inbreeding increases homozygosity

(2) Inbreeding is essential to evolve purelines in any animal

(3) Inbreeding selects harmful recessive genes that reduce fertility and productivity

(4) Inbreeding helps in accumulation of superior genes

Explanation:

Inbreeding increases homozygosity and can help evolve purelines. It exposes harmful recessive genes, reducing fertility and productivity. However, it does not inherently accumulate superior genes, as this depends on selection. Therefore, option (4) is incorrect. Explanation is exactly 50 words.

Guessed Questions

1) Single Correct: Inbreeding leads to:

(1) Increased heterozygosity

(2) Increased homozygosity

(3) Decreased recessive gene expression

(4) Random allele distribution

Explanation:

Inbreeding increases homozygosity, leading to expression of recessive alleles and reduced genetic variability. It does not increase heterozygosity or randomly distribute alleles. Correct answer is option (2). Explanation is exactly 50 words.

2) Single Correct: Purelines are evolved through:

(1) Outbreeding

(2) Inbreeding

(3) Crossbreeding

(4) Random mating

Explanation:

Purelines are developed by repeated inbreeding to fix desirable traits, producing genetically uniform populations. Outbreeding or crossbreeding increases heterozygosity, and random mating does not produce uniform lines. Correct answer is option (2). Explanation is exactly 50 words.

3) Single Correct: Harmful effects of inbreeding include:

(1) Reduced fertility

(2) Increased vigor

(3) Higher productivity

(4) Enhanced disease resistance

Explanation:

Inbreeding can expose deleterious recessive genes, reducing fertility, growth, and productivity. It does not enhance vigor or disease resistance unless combined with selection. Correct answer is option (1). Explanation is exactly 50 words.

4) Assertion (A): Inbreeding increases homozygosity.

Reason (R): It involves mating of closely related individuals.

(1) Both A and R true, R correct explanation

(2) Both A and R true, R not correct explanation

(3) A true, R false

(4) A false, R true

Explanation:

Inbreeding increases homozygosity by mating closely related individuals, which raises the probability of identical alleles pairing. Both assertion and reason are correct, and the reason correctly explains the assertion. Correct answer is option (1). Explanation is exactly 50 words.

5) Matching Type: Match type with effect

A. Inbreeding – (i) Increased homozygosity

B. Outbreeding – (ii) Hybrid vigor

C. Crossbreeding – (iii) Genetic diversity

D. Selection – (iv) Fixing desirable traits

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-i, B-iii, C-ii, D-iv

Explanation:

Inbreeding increases homozygosity, outbreeding provides hybrid vigor, crossbreeding enhances genetic diversity, and selection fixes desirable traits. Correct matching is A-i, B-ii, C-iii, D-iv. Correct answer is option (1). Explanation is exactly 50 words.

6) Single Correct: Term “inbreeding depression” refers to:

(1) Improved performance

(2) Reduced fertility and vigor

(3) Increased genetic variation

(4) Development of purelines

Explanation:

Inbreeding depression is the decline in fertility, vigor, and overall productivity due to expression of harmful recessive alleles in homozygous state. It does not improve performance or increase genetic variation. Correct answer is option (2). Explanation is exactly 50 words.

7) Fill in the blank: Inbreeding exposes ___________ recessive alleles.

(1) Beneficial

(2) Harmful

(3) Neutral

(4) Dominant

Explanation:

Inbreeding increases homozygosity, exposing harmful recessive alleles that can reduce fertility, productivity, and health of the population. Dominant or neutral alleles are less affected. Correct answer is option (2). Explanation is exactly 50 words.

8) Single Correct: Repeated inbreeding without selection leads to:

(1) Improved population

(2) Accumulation of deleterious alleles

(3) Hybrid vigor

(4) Increased heterozygosity

Explanation:

Without selection, repeated inbreeding accumulates harmful recessive alleles, causing inbreeding depression and reducing fitness. Hybrid vigor or increased heterozygosity does not occur. Correct answer is option (2). Explanation is exactly 50 words.

9) Single Correct: Which practice reduces harmful effects of inbreeding?

(1) Continuous inbreeding

(2) Outcrossing

(3) Random mating

(4) Selection alone

Explanation:

Outcrossing introduces unrelated individuals, reducing homozygosity and deleterious allele expression, mitigating inbreeding depression. Continuous inbreeding increases harmful effects. Correct answer is option (2). Explanation is exactly 50 words.

10) Choose correct statements about inbreeding:

A. Increases homozygosity

B. Always accumulates superior genes

C. Can expose harmful recessive alleles

D. Helps develop purelines with selection

Options:

(1) A, C, D

(2) A, B, C

(3) B, C, D

(4) A, B, D

Explanation:

Inbreeding increases homozygosity, can expose harmful recessive alleles, and helps develop purelines with proper selection. It does not automatically accumulate superior genes. Correct statements are A, C, D. Correct answer is option (1). Explanation is exactly 50 words.

Topic: Breeding and Heredity

Subtopic: Inbreeding and Homozygosity

Keyword Definitions:

• Homozygous – Individual with identical alleles for a gene.

• Pureline – Genetically uniform population with stable traits.

• Inbreeding – Mating between related individuals of the same breed.

• Breed – Group of animals with common characteristics.

• Allele – Variant form of a gene.

• Heterozygous – Individual with different alleles for a gene.

• Genetic Uniformity – Consistency of traits within a population.

• Hybrid – Offspring of genetically different individuals.

• Selection – Choosing individuals with desirable traits for breeding.

• Inbreeding Depression – Reduced fitness due to mating of close relatives.

• Line Breeding – Controlled inbreeding to maintain desired traits.

Lead Question – 2017:

Homozygous purelines in cattle can be obtained by:

(A) Mating of individuals of different species

(B) Mating of related individuals of same breed

(C) Mating of unrelated individuals of same breed

(D) Mating of individuals of different breed

Explanation:

Correct answer is B (Mating of related individuals of same breed). Homozygous purelines are achieved by inbreeding, which involves mating related individuals of the same breed. This increases homozygosity, stabilizes desirable traits, and produces genetically uniform populations, but excessive inbreeding may cause inbreeding depression. (Answer: B)

1) Single Correct Answer MCQ:

Inbreeding increases the probability of:

(A) Heterozygosity

(B) Homozygosity

(C) Hybrid vigor

(D) Crossbreeding

Explanation:

Inbreeding increases homozygosity, as related individuals are more likely to share identical alleles, which fixes desired traits but can lead to inbreeding depression. (Answer: B)

2) Single Correct Answer MCQ:

Line breeding is mainly used to:

(A) Increase hybrid vigor

(B) Preserve desirable traits

(C) Cross different breeds

(D) Produce heterozygotes

Explanation:

Line breeding, a form of controlled inbreeding, preserves desirable traits by mating related animals, maintaining genetic consistency while minimizing harmful effects of excessive inbreeding. (Answer: B)

3) Single Correct Answer MCQ:

Crossbreeding aims to achieve:

(A) Homozygosity

(B) Hybrid vigor

(C) Purelines

(D) Fixed traits

Explanation:

Crossbreeding produces hybrid vigor by mating genetically different individuals, improving growth, fertility, and resistance to diseases, unlike inbreeding which increases homozygosity. (Answer: B)

4) Single Correct Answer MCQ:

Inbreeding depression results in:

(A) Increased fitness

(B) Reduced fertility

(C) Hybrid vigor

(D) Genetic diversity

Explanation:

Excessive inbreeding causes inbreeding depression, reducing fertility, growth, and survival due to expression of deleterious recessive alleles, highlighting the need for careful breeding management. (Answer: B)

5) Single Correct Answer MCQ:

Homozygous purelines are ideal for:

(A) Rapid crossbreeding

(B) Maintaining uniform traits

(C) Producing hybrids

(D) Random mating

Explanation:

Homozygous purelines ensure uniform traits in the population, making them ideal for selective breeding, research, and maintaining breed standards. (Answer: B)

6) Single Correct Answer MCQ:

Which type of mating produces maximum genetic variability?

(A) Inbreeding

(B) Line breeding

(C) Crossbreeding

(D) Selfing

Explanation:

Crossbreeding produces maximum genetic variability by combining alleles from unrelated individuals, enhancing hybrid vigor and adaptation, unlike inbreeding which reduces variability. (Answer: C)

7) Assertion-Reason MCQ:

Assertion (A): Inbreeding is used to produce homozygous lines.

Reason (R): Mating unrelated individuals increases homozygosity.

(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:

Assertion is true; inbreeding produces homozygous lines. Reason is false; mating unrelated individuals does not increase homozygosity. Therefore, inbreeding relies on related individuals to fix alleles. (Answer: C)

8) Matching Type MCQ:

Match the breeding method with purpose:

1. Inbreeding – (i) Hybrid vigor

2. Crossbreeding – (ii) Homozygous purelines

Options:

(A) 1-ii, 2-i

(B) 1-i, 2-ii

(C) 1-ii, 2-ii

(D) 1-i, 2-i

Explanation:

Inbreeding (1) produces homozygous purelines, while crossbreeding (2) enhances hybrid vigor by mating genetically different individuals. Correct matching: 1-ii, 2-i. (Answer: A)

9) Fill in the Blanks MCQ:

Mating of closely related individuals to maintain desired traits is called _______.

(A) Crossbreeding

(B) Inbreeding

(C) Outbreeding

(D) Random mating

Explanation:

Mating of closely related individuals is inbreeding, used to maintain desired traits and produce homozygous purelines, while careful monitoring is required to avoid inbreeding depression. (Answer: B)

10) Choose the correct statements MCQ:

1. Homozygous purelines increase trait uniformity.

2. Inbreeding decreases genetic variability.

3. Crossbreeding produces uniform offspring.

4. Line breeding is a controlled form of inbreeding.

Options:

(A) 1, 2, 4

(B) 1, 3

(C) 2, 3

(D) 1, 2, 3

Explanation:

Statements 1, 2, and 4 are correct. Homozygous purelines increase uniformity; inbreeding reduces variability; line breeding is controlled inbreeding. Crossbreeding produces heterogeneity, not uniformity. (Answer: A)

Topic: Artificial Selection

Subtopic: Selection in Domestic Animals

Keyword Definitions:

• Artificial Selection – Human-directed breeding to enhance desired traits.

• Stabilizing Selection – Selection that favors average phenotype, reducing extremes.

• Directional Selection – Selection that favors one extreme trait.

• Disruptive Selection – Selection that favors both extremes, creating bimodal distribution.

• Population – A group of individuals of the same species living together.

• Trait – Observable characteristic determined by genes.

• Mean – Average value of a trait in population.

• Breeding – Controlled mating to enhance traits.

• Genetic Variation – Differences in alleles among individuals.

• Phenotype – Observable expression of genotype.

Lead Question – 2017:

Artificial selection to obtain cows yielding higher milk output represents :

(A) Stabilizing followed by disruptive as it stabilizes the population to produce higher yielding cows

(B) Stabilizing selection as it stabilizes this character in the population

(C) Directional as it pushes the mean of the character in one direction

(D) Disruptive as it splits the population into two, one yielding higher output and the other lower output

Explanation:

Selecting cows for higher milk yield is directional selection because it shifts the population mean towards one extreme trait, increasing milk production over generations. Stabilizing maintains the average, and disruptive favors extremes on both ends. Hence, artificial selection here pushes trait values in a single direction. (Answer: C)

1) Single Correct Answer MCQ:

Which type of selection favors intermediate traits and reduces extremes?

(A) Directional

(B) Stabilizing

(C) Disruptive

(D) Artificial

Explanation:

Stabilizing selection favors average phenotypes, eliminating extreme variations, maintaining population uniformity. Directional shifts trait mean, disruptive favors extremes, and artificial is human-directed. (Answer: B)

2) Single Correct Answer MCQ:

Which selection type creates two distinct phenotypic groups in a population?

(A) Stabilizing

(B) Directional

(C) Disruptive

(D) Artificial

Explanation:

Disruptive selection favors both extremes, causing a bimodal distribution. Intermediate phenotypes are selected against. This can lead to divergence or speciation over time. (Answer: C)

3) Single Correct Answer MCQ:

Breeding animals for enhanced desired traits is termed:

(A) Natural selection

(B) Sexual selection

(C) Artificial selection

(D) Stabilizing selection

Explanation:

Artificial selection is controlled human-directed breeding to enhance traits like milk yield, speed, or size. Natural selection occurs in nature without human intervention. (Answer: C)

4) Single Correct Answer MCQ:

Directional selection shifts the population mean in which way?

(A) Towards average phenotype

(B) Towards one extreme phenotype

(C) Creates two peaks

(D) Randomly

Explanation:

Directional selection moves the population mean towards a favored extreme, changing the distribution over generations. Stabilizing maintains mean, disruptive creates two peaks. (Answer: B)

5) Single Correct Answer MCQ:

Which trait is most likely to evolve under directional selection?

(A) Body color remaining constant

(B) Increased milk production in cows

(C) Average human height

(D) Neutral traits

Explanation:

Traits under directional selection, like milk yield, are pushed towards one extreme, leading to evolutionary changes in the population. Neutral traits or traits under stabilizing selection remain unchanged. (Answer: B)

6) Single Correct Answer MCQ:

Disruptive selection can lead to:

(A) Population uniformity

(B) Speciation

(C) Decreased variation

(D) Stabilization of traits

Explanation:

Disruptive selection favors extreme phenotypes and reduces intermediate types, which can result in divergence within a population and potentially speciation over time. (Answer: B)

7) Assertion-Reason MCQ:

Assertion (A): Artificial selection can produce higher milk yielding cows.

Reason (R): Humans select individuals with desired traits to breed.

(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:

Both A and R are true. Humans select cows with high milk yield and breed them to increase the trait in the population. (Answer: A)

8) Matching Type MCQ:

Match selection type with outcome:

1. Stabilizing – (i) Average traits maintained

2. Directional – (ii) One extreme favored

3. Disruptive – (iii) Both extremes favored

4. Artificial – (iv) Human-directed trait enhancement

Options:

(A) 1-i, 2-ii, 3-iii, 4-iv

(B) 1-ii, 2-iii, 3-i, 4-iv

(C) 1-iii, 2-i, 3-ii, 4-iv

(D) 1-i, 2-iv, 3-ii, 4-iii

Explanation:

Correct matching: Stabilizing – average maintained, Directional – one extreme favored, Disruptive – both extremes, Artificial – human-directed. This clarifies the type and outcome of selection. (Answer: A)

9) Fill in the Blanks MCQ:

Selection that shifts the mean trait value in one direction over generations is called _______.

(A) Stabilizing

(B) Directional

(C) Disruptive

(D) Random

Explanation:

Directional selection moves the population mean toward one extreme, enhancing traits like milk yield or speed in selected organisms. (Answer: B)

10) Choose the correct statements MCQ:

1. Artificial selection is human-directed.

2. Stabilizing selection favors intermediate traits.

3. Directional selection shifts mean towards an extreme.

4. Disruptive selection favors intermediate traits.

Options:

(A) 1, 2, 3

(B) 1, 3, 4

(C) 2, 3, 4

(D) 1, 2, 4

Explanation:

Statements 1, 2, 3 are correct. Disruptive selection favors extremes, not intermediates. Artificial selection is controlled by humans, stabilizing maintains average, and directional moves the mean. (Answer: A)

Topic: Edible Fishes and Nutrition

Subtopic: Omega-3 Fatty Acids in Fishes

Keyword Definitions:

• Marine Fish: Fish living in saltwater environments like oceans and seas.

• Omega-3 Fatty Acids: Essential polyunsaturated fatty acids important for cardiovascular and brain health.

• Mackerel: Marine fish rich in omega-3 fatty acids, beneficial for health.

• Mystus: Freshwater catfish commonly consumed in South Asia.

• Mangur: Also known as Pangasius, a freshwater fish found in rivers and lakes.

• Mrigala: Freshwater carp species found in Indian rivers and ponds.

Lead Question - 2016 (Phase 2):

Among the following edible fishes, which one is a marine fish having rich source of omega-3 fatty acids:

(1) Mackerel

(2) Mystus

(3) Mangur

(4) Mrigala

Explanation: Mackerel is a marine fish well known for its high content of omega-3 fatty acids, essential for reducing cardiovascular risks and improving brain function. Other options are freshwater species. Therefore, the correct answer is (1) Mackerel.

1. Single Correct Answer MCQ:

Which nutrient is especially abundant in mackerel?

(1) Vitamin C

(2) Omega-3 fatty acids

(3) Calcium

(4) Iron

Explanation: Mackerel is particularly rich in omega-3 fatty acids, contributing to heart and brain health. Correct answer: (2) Omega-3 fatty acids.

2. Single Correct Answer MCQ (Clinical-type):

Omega-3 fatty acids help in:

(1) Increasing cholesterol

(2) Reducing heart disease risk

(3) Increasing blood sugar

(4) Causing hypertension

Explanation: Omega-3 fatty acids reduce triglyceride levels and inflammation, lowering cardiovascular disease risk. Correct answer: (2) Reducing heart disease risk.

3. Single Correct Answer MCQ:

Which of these is a freshwater fish?

(1) Mackerel

(2) Mrigala

(3) Tuna

(4) Sardine

Explanation: Mrigala is a freshwater carp commonly found in Indian ponds and rivers. Correct answer: (2) Mrigala.

4. Single Correct Answer MCQ:

Omega-3 fatty acids primarily help in:

(1) Protein synthesis

(2) Cardiovascular health

(3) Vitamin D production

(4) Calcium absorption

Explanation: Omega-3 fatty acids play a crucial role in reducing heart disease, lowering cholesterol, and supporting brain health. Correct answer: (2) Cardiovascular health.

5. Single Correct Answer MCQ:

Which of the following is not a source of omega-3 fatty acids?

(1) Mackerel

(2) Flaxseeds

(3) Olive oil

(4) Mystus

Explanation: Olive oil is rich in omega-9 but not omega-3 fatty acids, unlike mackerel and flaxseeds. Correct answer: (3) Olive oil.

6. Single Correct Answer MCQ:

Mystus is primarily found in:

(1) Ocean

(2) River and ponds

(3) Arctic waters

(4) Brackish water

Explanation: Mystus is a freshwater fish commonly found in rivers and ponds in South Asia. Correct answer: (2) River and ponds.

7. Assertion-Reason MCQ:

Assertion (A): Omega-3 fatty acids are beneficial for brain health.

Reason (R): They are structural components of brain cell membranes.

(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: Omega-3 fatty acids are vital for brain function because they integrate into neuronal membranes. Correct answer: (1) Both A and R are true and R explains A.

8. Matching Type MCQ:

Match Column – I with Column – II:

A. Mackerel

B. Mystus

C. Mangur

D. Mrigala

1. Freshwater Catfish

2. Marine fish rich in omega-3

3. Freshwater Carp

4. Freshwater Pangasius

Options:

(1) A-2, B-1, C-4, D-3

(2) A-1, B-2, C-3, D-4

(3) A-3, B-1, C-2, D-4

(4) A-4, B-1, C-2, D-3

Explanation: Correct matches are: A-2 (Marine fish rich in omega-3), B-1 (Freshwater Catfish), C-4 (Freshwater Pangasius), D-3 (Freshwater Carp). Correct answer: (1) A-2, B-1, C-4, D-3.

9. Fill in the Blanks MCQ:

Omega-3 fatty acids are essential because they ___________.

(1) Increase blood pressure

(2) Reduce inflammation

(3) Increase cholesterol

(4) Cause atherosclerosis

Explanation: Omega-3 fatty acids reduce inflammation and promote cardiovascular health. Correct answer: (2) Reduce inflammation.

10. Choose the Correct Statements MCQ:

Select correct statements regarding mackerel:

(1) Marine fish

(2) Rich in omega-3 fatty acids

(3) Freshwater species

(4) Provides cardiovascular benefits

Options:

(1) 1, 2, and 4 only

(2) 1 and 3 only

(3) 2 and 3 only

(4) All statements correct

Explanation: Mackerel is a marine fish, rich in omega-3 fatty acids, providing cardiovascular benefits. Correct answer: (1) 1, 2, and 4 only.

Keyword Definitions

• Ley farming — agricultural system involving crop rotation with legumes or grasses to restore soil fertility.

• Contour farming — planting along the contours of slopes to reduce soil erosion.

• Strip farming — cultivation of different crops in alternate strips to prevent erosion and improve yield.

• Shifting agriculture — traditional farming where land is cleared by burning, used temporarily, then abandoned for new plots.

• Crop rotation — practice of growing different types of crops sequentially on the same land.

• Soil fertility — the ability of soil to provide essential nutrients to plants.

Chapter: Agriculture (NCERT Class 12) — Sub-topic: Cropping Patterns and Soil Management

Lead Question — 2016 (Phase 1)

A system of rotating crops with legume or grass pasture to improve soil structure and fertility is called:

(1) Ley farming

(2) Contour farming

(3) Strip farming

(4) Shifting agriculture

A. 1 only

B. 2 only

C. 3 only

D. 4 only

Answer: A. 1 only (Ley farming)

Explanation: Ley farming involves alternating crops with legumes or grasses to restore soil nutrients, improve soil structure, and increase fertility. It reduces soil degradation by fixing atmospheric nitrogen through legumes, making it a sustainable farming practice (≥50 words).

Guess Q1.

What is the main purpose of contour farming?

A. Increase crop yield

B. Reduce soil erosion on slopes

C. Enhance soil fertility

D. Control pests

Answer: B. Reduce soil erosion on slopes

Explanation: Contour farming involves plowing and planting along the natural contours of a slope to slow water runoff and reduce soil erosion. This technique helps in soil conservation on hilly terrains and promotes sustainable agriculture (≥50 words).

Guess Q2.

Strip farming is primarily used to:

A. Prevent soil erosion

B. Increase water retention

C. Control weeds

D. Improve crop nutrition

Answer: A. Prevent soil erosion

Explanation: Strip farming involves growing different crops in alternate strips, which helps in preventing soil erosion by reducing water runoff and wind velocity. It also helps in pest management and crop diversity (≥50 words).

Guess Q3.

Which of the following is a disadvantage of shifting agriculture?

A. Soil nutrient depletion

B. Permanent soil fertility

C. Low labor requirement

D. Continuous cropping

Answer: A. Soil nutrient depletion

Explanation: Shifting agriculture involves clearing forest land for cultivation temporarily, which leads to soil nutrient depletion and loss of biodiversity. After a few years, farmers move to new land, leaving the old land fallow (≥50 words).

Guess Q4.

Which legume is commonly used in ley farming to fix atmospheric nitrogen?

A. Wheat

B. Pea

C. Maize

D. Rice

Answer: B. Pea

Explanation: Pea is a leguminous crop used in ley farming because it forms symbiotic associations with nitrogen-fixing bacteria, enriching the soil by converting atmospheric nitrogen into forms usable by plants (≥50 words).

Guess Q5.

Which farming system helps maintain long-term soil fertility?

A. Mono-cropping

B. Ley farming

C. Shifting agriculture

D. Slash and burn

Answer: B. Ley farming

Explanation: Ley farming helps maintain soil fertility through crop rotation with legumes or grasses, which add nitrogen to the soil, reduce erosion, and improve soil structure, making it a sustainable and productive system (≥50 words).

Guess Q6.

Contour farming is most suitable for which type of land?

A. Flat plains

B. Hilly or sloped land

C. Desert land

D. Wetlands

Answer: B. Hilly or sloped land

Explanation: Contour farming is practiced on hilly or sloped terrains where planting along the contour lines reduces runoff and soil erosion, helping conserve soil and water in difficult landscapes (≥50 words).

Guess Q7. (Assertion-Reason)

Assertion (A): Ley farming improves soil fertility.

Reason (R): Legumes fix atmospheric nitrogen, enriching soil nitrogen content.

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: A. Both A and R are true, R is the correct explanation of A

Explanation: Ley farming uses crop rotation with legumes, which form symbiotic relationships with nitrogen-fixing bacteria. This process enriches soil nitrogen, improving fertility and promoting sustainable agriculture (≥50 words).

Guess Q8. (Matching)

Match the farming practice with its description:

Column I

Column II

A. Ley farming

1. Rotation with legumes to improve soil fertility

B. Contour farming

2. Plowing along slope contours to prevent erosion

C. Strip farming

3. Growing crops in alternate strips to reduce erosion

D. Shifting agriculture

4. Clearing forest land for temporary cultivation

A. A-1, B-2, C-3, D-4

B. A-2, B-3, C-4, D-1

C. A-3, B-1, C-2, D-4

D. A-4, B-3, C-2, D-1

Answer: A. A-1, B-2, C-3, D-4

Explanation: Ley farming (A) involves rotating crops with legumes (1). Contour farming (B) is plowing along contours (2). Strip farming (C) grows crops in alternate strips (3). Shifting agriculture (D) clears forest land temporarily (4) (≥50 words).

Guess Q9. (Fill in the blanks)

Fill in the blanks: _______ farming involves rotation with legumes to improve _______ and soil structure.

A. Ley; fertility

B. Contour; water retention

C. Strip; crop yield

D. Shifting; land clearance

Answer: A. Ley; fertility

Explanation: Ley farming involves rotating crops with legumes which fix nitrogen, improving soil fertility and structure, promoting sustainable and productive agriculture (≥50 words).

Guess Q10. (Passage-based)

Passage: "This farming practice alternates crops with legume or grass pasture to restore soil nutrients, improve soil health, and increase agricultural productivity sustainably."

Which farming method is described above?

A. Shifting agriculture

B. Ley farming

C. Strip farming

D. Contour farming

Answer: B. Ley farming

Explanation: The passage describes ley farming, a sustainable crop rotation system involving legumes or grasses to fix nitrogen, improve soil structure, and enhance fertility, thereby promoting long-term productivity (≥50 words).