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.
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).