ROUTERA


Chapter 9 Strategies for Enhancement in Food Production

Class 12th Biology Chapter MCQs


1. Which of the following is the major technique used in plant breeding to increase the yield of crops?

  • A) Hybridization
  • B) Cloning
  • C) Grafting
  • D) Mutation

Answer: A
Explanation: Hybridization is the process of crossing two different plants to combine their desirable characteristics, such as higher yield, disease resistance, etc.


2. Which of the following is an example of a biofortified crop?

  • A) Golden rice
  • B) Bt cotton
  • C) Herbicide-tolerant soybeans
  • D) Wheat

Answer: A
Explanation: Golden rice is a biofortified crop, engineered to produce higher levels of Vitamin A to combat vitamin deficiencies in developing countries.


3. The technique of tissue culture is used in which of the following?

  • A) Pest control
  • B) Cloning of plants
  • C) Soil fertility enhancement
  • D) Crop rotation

Answer: B
Explanation: Tissue culture is a technique used to grow plant cells, tissues, or organs in a sterile environment to produce genetically identical plants.


4. Which of the following crops is a result of hybridization between different species?

  • A) Triticale
  • B) Rice
  • C) Wheat
  • D) Banana

Answer: A
Explanation: Triticale is a hybrid crop developed by crossing wheat (Triticum) and rye (Secale), combining their beneficial traits such as disease resistance and high yield.


5. Which of the following is a primary aim of crop improvement?

  • A) Disease resistance
  • B) High yield
  • C) Better quality
  • D) All of the above

Answer: D
Explanation: Crop improvement aims at enhancing multiple aspects, including disease resistance, high yield, and better quality to meet the growing demand for food.


6. Which of the following is a genetically modified crop resistant to pests?

  • A) Bt cotton
  • B) Golden rice
  • C) Triticale
  • D) Maize

Answer: A
Explanation: Bt cotton is genetically modified to produce a toxin from the bacterium Bacillus thuringiensis that is toxic to certain pests, reducing the need for chemical pesticides.


7. Which of the following techniques is used to increase the shelf life of crops?

  • A) Genetic engineering
  • B) Crossbreeding
  • C) Tissue culture
  • D) Cryopreservation

Answer: D
Explanation: Cryopreservation involves freezing plant material at very low temperatures to preserve it for long periods, thereby enhancing the shelf life of crops.


8. Which of the following is used to control the growth of weeds in agricultural fields?

  • A) Herbicides
  • B) Pesticides
  • C) Insecticides
  • D) Fungicides

Answer: A
Explanation: Herbicides are chemicals used to control or kill unwanted plants (weeds) that compete with crops for nutrients, water, and sunlight.


9. Which of the following is an example of a plant growth regulator used in agriculture?

  • A) IAA (Indole-3-acetic acid)
  • B) DNA
  • C) Toxin
  • D) Phytochrome

Answer: A
Explanation: IAA (Indole-3-acetic acid) is a naturally occurring plant hormone involved in plant growth regulation, commonly used to induce rooting and promote growth.


10. What is the main purpose of using crossbreeding in animal husbandry?

  • A) To increase genetic diversity
  • B) To improve the quality and quantity of animal products
  • C) To eliminate genetic disorders
  • D) To prevent inbreeding

Answer: B
Explanation: Crossbreeding is used to combine the desirable traits of two different breeds to enhance quality and quantity of animal products, such as milk, meat, and wool.


11. Which of the following is a characteristic of genetically modified (GM) crops?

  • A) They are always resistant to all pests
  • B) They have enhanced nutritional value
  • C) They are only resistant to drought
  • D) They are only suitable for temperate regions

Answer: B
Explanation: GM crops can be engineered to have enhanced nutritional value, such as Golden rice with increased vitamin A content.


12. Which of the following is a disadvantage of using chemical fertilizers?

  • A) Increase in soil fertility
  • B) Pollution of water bodies
  • C) Increased crop yield
  • D) None of the above

Answer: B
Explanation: Chemical fertilizers can lead to water pollution when they run off into water bodies, causing eutrophication and harming aquatic ecosystems.


13. What is the term used for the process of transferring genes from one organism to another?

  • A) Gene editing
  • B) Genetic engineering
  • C) Cloning
  • D) Crossbreeding

Answer: B
Explanation: Genetic engineering is the process of transferring specific genes from one organism to another to achieve desired traits, such as pest resistance in crops.


14. Which of the following is a major pest of rice?

  • A) Pink bollworm
  • B) Whitefly
  • C) Rice weevil
  • D) Termite

Answer: C
Explanation: The rice weevil is a significant pest of rice, damaging stored grains and reducing yield quality.


15. Which of the following is a characteristic of polyploidy in plants?

  • A) It decreases the size of the plant
  • B) It results in the formation of sterile plants
  • C) It can lead to larger and more robust plants
  • D) It is used to produce hybrid seeds

Answer: C
Explanation: Polyploidy refers to the condition where a plant has more than two sets of chromosomes, often resulting in larger and more robust plants with better yield.


16. Which of the following is the most commonly used artificial method for improving the genetic traits of animals?

  • A) Cloning
  • B) Crossbreeding
  • C) Genetic engineering
  • D) Tissue culture

Answer: B
Explanation: Crossbreeding is commonly used in animal husbandry to combine the desirable traits of different breeds, such as higher milk production or disease resistance.


17. Which microorganism is used in the production of alcoholic beverages?

  • A) Bacteria
  • B) Fungi
  • C) Algae
  • D) Viruses

Answer: B
Explanation: Yeasts, a type of fungus, are used in the fermentation process to produce alcoholic beverages like beer and wine.


18. What is the purpose of the 'Green Revolution'?

  • A) To promote organic farming
  • B) To increase food production using high-yielding varieties
  • C) To encourage the use of traditional farming methods
  • D) To reduce the use of chemical fertilizers

Answer: B
Explanation: The Green Revolution involved the development and use of high-yielding varieties (HYVs), chemical fertilizers, and irrigation techniques to increase food production.


19. Which of the following is an example of a transgenic animal?

  • A) Bt cotton
  • B) Fish with growth hormone genes
  • C) Golden rice
  • D) Triticale

Answer: B
Explanation: A transgenic animal contains genes transferred from another species, such as a fish that has been engineered to contain growth hormone genes to accelerate growth.


20. Which of the following statements is true about organic farming?

  • A) It uses synthetic pesticides and fertilizers
  • B) It involves crop rotation and green manure
  • C) It depends on genetically modified crops
  • D) It is only practiced in developed countries

Answer: B
Explanation: Organic farming relies on natural processes such as crop rotation, green manure, and composting, and does not use synthetic chemicals.


21. Which of the following is the major advantage of using organic farming?

  • A) Higher yield than conventional farming
  • B) Lesser environmental impact
  • C) More chemical use
  • D) Requires more water

Answer: B
Explanation: Organic farming generally has a lesser environmental impact because it avoids the use of synthetic chemicals, focusing on natural practices like crop rotation and composting.


22. Which of the following is a method of improving soil fertility?

  • A) Use of chemical fertilizers
  • B) Use of organic fertilizers
  • C) Crop rotation
  • D) All of the above

Answer: D
Explanation: All of the above methods help improve soil fertility. Chemical fertilizers provide nutrients, organic fertilizers enhance microbial activity, and crop rotation helps prevent soil depletion.


23. Which of the following is a disease caused by a deficiency of Vitamin A?

  • A) Rickets
  • B) Beriberi
  • C) Night blindness
  • D) Pellagra

Answer: C
Explanation: Night blindness is a condition caused by Vitamin A deficiency, which impairs the ability to see in low light.


24. Which of the following hormones is used in the artificial ripening of fruits?

  • A) Ethylene
  • B) Gibberellin
  • C) Auxin
  • D) Cytokinin

Answer: A
Explanation: Ethylene is a plant hormone that is used for artificially ripening fruits like bananas and tomatoes.


25. Which of the following is the primary objective of cryopreservation in plant breeding?

  • A) To maintain genetic diversity
  • B) To produce genetically modified organisms
  • C) To prevent soil erosion
  • D) To increase crop yield

Answer: A
Explanation: Cryopreservation is used to preserve plant germplasm (seeds, tissues) in a frozen state to maintain genetic diversity for future breeding.


26. Which of the following organisms is used to enhance nitrogen fixation in soil?

  • A) Rhizobium
  • B) Azotobacter
  • C) Cyanobacteria
  • D) All of the above

Answer: D
Explanation: Rhizobium, Azotobacter, and Cyanobacteria all play a key role in nitrogen fixation, converting atmospheric nitrogen into usable forms for plants.


27. Which of the following is a technique used for the production of disease-free plants?

  • A) Micropropagation
  • B) Hybridization
  • C) Cross-pollination
  • D) Transgenesis

Answer: A
Explanation: Micropropagation is a tissue culture technique used to produce disease-free plants by propagating them from a small tissue sample under sterile conditions.


28. Which of the following plant breeding methods helps in improving disease resistance?

  • A) Crossbreeding
  • B) Hybridization
  • C) Mutation breeding
  • D) Selection

Answer: D
Explanation: Selection is a method where the best plants (with desirable traits like disease resistance) are selected and propagated to improve future generations.


29. What is the primary function of 'Bt' toxin in genetically modified crops?

  • A) To promote growth
  • B) To kill pests
  • C) To improve yield
  • D) To enhance nutritional value

Answer: B
Explanation: The Bt toxin in genetically modified crops, such as Bt cotton, produces a protein that is toxic to specific insect pests, helping to protect the crops from damage.


30. Which of the following is the major drawback of monoculture farming?

  • A) Increased yield
  • B) Increased biodiversity
  • C) Soil depletion and pest buildup
  • D) Efficient use of water

Answer: C
Explanation: Monoculture farming involves growing a single crop over large areas, which can lead to soil depletion and an increase in pest populations due to the lack of crop diversity.


31. Which of the following is not a benefit of genetically modified crops?

  • A) Increased resistance to pests
  • B) Higher nutritional content
  • C) Increased production costs
  • D) Reduced dependency on chemical pesticides

Answer: C
Explanation: Genetically modified crops generally result in lower production costs by reducing the need for chemical pesticides and increasing yield through pest resistance.


32. Which of the following is the term for the practice of growing different crops in a field over different seasons?

  • A) Agroforestry
  • B) Crop rotation
  • C) Polyculture
  • D) Mixed cropping

Answer: B
Explanation: Crop rotation involves growing different crops in a specific sequence on the same piece of land to maintain soil fertility and reduce pest buildup.


33. Which of the following is a synthetic nitrogen-fixing biofertilizer?

  • A) Rhizobium
  • B) Azotobacter
  • C) Azospirillum
  • D) All of the above

Answer: D
Explanation: Rhizobium, Azotobacter, and Azospirillum are nitrogen-fixing bacteria that are used as biofertilizers to enhance soil fertility.


34. Which of the following is an example of a food crop genetically engineered for increased shelf life?

  • A) Bt cotton
  • B) Golden rice
  • C) Flavr-Savr tomato
  • D) Triticale

Answer: C
Explanation: Flavr-Savr tomato is genetically engineered to have a longer shelf life by delaying ripening, reducing spoilage.


35. Which of the following is a non-edible product of biotechnology used in agriculture?

  • A) Biofuel
  • B) Herbicide-resistant crops
  • C) Biodegradable plastic
  • D) All of the above

Answer: D
Explanation: Biotechnology has applications in agriculture for producing biofuels, herbicide-resistant crops, and biodegradable plastics, which are not directly edible but have significant agricultural benefits.


36. Which of the following is an advantage of using biopesticides over chemical pesticides?

  • A) Long shelf life
  • B) They are less toxic to humans and other non-target organisms
  • C) They are more effective
  • D) They are cheaper to produce

Answer: B
Explanation: Biopesticides are derived from natural materials and are less toxic to humans and other non-target organisms, making them an environmentally friendly alternative to chemical pesticides.


37. What is the main aim of using microbial inoculants in agriculture?

  • A) To control pests
  • B) To increase soil fertility
  • C) To increase crop yield by controlling weeds
  • D) To enhance plant growth by providing essential nutrients

Answer: B
Explanation: Microbial inoculants are used in agriculture to introduce beneficial microbes into the soil, enhancing soil fertility and promoting plant growth.


38. Which of the following is an example of a biotechnological method used to improve livestock?

  • A) Artificial insemination
  • B) Crossbreeding
  • C) Somatic hybridization
  • D) Use of growth hormones

Answer: A
Explanation: Artificial insemination is a biotechnology technique used to improve livestock by selecting high-quality genetic material for breeding, increasing yield, and preventing the spread of diseases.


39. What is the main characteristic of genetically modified (GM) crops?

  • A) Resistance to all types of pests
  • B) Ability to grow in all soil conditions
  • C) Modified to exhibit specific traits like pest resistance or drought tolerance
  • D) They have a longer shelf life

Answer: C
Explanation: GM crops are modified to express specific traits, such as pest resistance, drought tolerance, or improved nutritional content, depending on the genetic modification.


40. Which of the following is a disadvantage of monoculture?

  • A) Improved yield stability
  • B) Increased pest resistance
  • C) Increased risk of disease outbreaks
  • D) Enhanced soil fertility

Answer: C
Explanation: Monoculture increases the risk of disease outbreaks as a single pathogen can affect the entire crop, reducing yield and quality.


41. Which of the following helps in increasing the genetic diversity of crops?

  • A) Hybridization
  • B) Cloning
  • C) Cross-pollination
  • D) Both A and C

Answer: D
Explanation: Hybridization and cross-pollination both increase genetic diversity by combining different genetic traits from different plants.


42. Which of the following is a practice associated with sustainable agriculture?

  • A) Heavy use of chemical fertilizers
  • B) Use of genetically modified crops
  • C) Crop rotation and conservation tillage
  • D) Use of monoculture farming

Answer: C
Explanation: Sustainable agriculture focuses on practices like crop rotation and conservation tillage to protect the environment, maintain soil health, and reduce chemical inputs.


43. Which of the following is not a part of integrated pest management (IPM)?

  • A) Biological control
  • B) Chemical control
  • C) Cultural practices
  • D) Monoculture

Answer: D
Explanation: Monoculture is not part of Integrated Pest Management (IPM) because it can increase pest vulnerability. IPM involves biological control, chemical control, and cultural practices to manage pests sustainably.


44. Which of the following is the primary source of plant nutrients in organic farming?

  • A) Synthetic fertilizers
  • B) Organic fertilizers like compost and manure
  • C) Pesticides
  • D) Herbicides

Answer: B
Explanation: In organic farming, plant nutrients are primarily supplied through organic fertilizers like compost and manure, which are rich in nutrients and enhance soil health.


45. Which of the following is a biotic factor that influences plant growth?

  • A) Temperature
  • B) Water
  • C) Soil composition
  • D) Presence of herbivores

Answer: D
Explanation: Herbivores are a biotic factor that can affect plant growth by consuming plant tissues and reducing plant population density.


46. Which of the following is the main purpose of genetic modification in crops?

  • A) To increase crop diversity
  • B) To reduce water consumption
  • C) To introduce beneficial traits like pest resistance
  • D) To increase labor costs

Answer: C
Explanation: Genetic modification is primarily used to introduce beneficial traits into crops, such as pest resistance or drought tolerance, to improve agricultural productivity.


47. Which of the following is an example of a renewable resource used in agriculture?

  • A) Fossil fuels
  • B) Water
  • C) Soil
  • D) Pesticides

Answer: B
Explanation: Water is a renewable resource used in agriculture, provided it is managed sustainably and replenished naturally through the water cycle.


48. Which of the following is true about intercropping?

  • A) Growing only one type of crop
  • B) Growing two or more crops in the same field
  • C) Growing crops in isolated fields
  • D) Using chemical pesticides

Answer: B
Explanation: Intercropping involves growing two or more crops simultaneously in the same field, often to reduce pest pressure and improve soil health.


49. Which of the following practices is commonly used to prevent soil erosion in agriculture?

  • A) Terracing
  • B) Use of pesticides
  • C) Overgrazing
  • D) Slash-and-burn agriculture

Answer: A
Explanation: Terracing is a technique used to prevent soil erosion, especially on sloped land, by creating flat areas that slow down water runoff.


50. Which of the following is an example of a biofertilizer?

  • A) Urea
  • B) Ammonium nitrate
  • C) Rhizobium
  • D) Potassium chloride

Answer: C
Explanation: Rhizobium is a biofertilizer that helps fix nitrogen in the soil, enhancing soil fertility and supporting plant growth.