ROUTERA


Chapter 9 Strategies for Enhancement in Food Production

Class 12th Biology Chapter Case Study


Case Study 1: Improvement in Crop Yields through Crossbreeding

In India, the Green Revolution led to significant improvements in crop yields, especially in staple crops like wheat and rice. The development of high-yielding varieties (HYVs) was one of the key aspects of this revolution. Crossbreeding of traditional varieties with superior varieties helped produce seeds that were more resistant to diseases, pests, and environmental stresses. For instance, hybrid varieties of wheat, such as Kalyan Sona and Sonora 64, were developed for high productivity.

Questions:

  1. High-yielding varieties (HYVs) were developed by crossbreeding to achieve:

    • A) Increased disease resistance
    • B) Increased photosynthesis efficiency
    • C) High productivity
    • D) All of the above

    Answer: D) All of the above

  2. Which of the following is NOT an advantage of high-yielding varieties (HYVs)?

    • A) Increased resistance to pests and diseases
    • B) Enhanced drought resistance
    • C) Increased fertilizer and water requirements
    • D) Reduced pesticide use

    Answer: D) Reduced pesticide use

  3. The process of creating hybrid varieties involves:

    • A) Genetic modification of crops
    • B) Crossbreeding of genetically distinct varieties
    • C) Introduction of foreign genes through biotechnology
    • D) Selection of varieties with high growth rate

    Answer: B) Crossbreeding of genetically distinct varieties

  4. Which of the following crops was significantly improved during the Green Revolution in India?

    • A) Potato
    • B) Rice
    • C) Tomato
    • D) Banana

    Answer: B) Rice


Case Study 2: In Vitro Fertilization in Animal Breeding

Dr. Sharma, an animal breeder, was working on improving the milk yield of a specific breed of cattle. She employed in vitro fertilization (IVF) techniques, where the sperm from a superior male cow was used to fertilize the eggs of a female cow in a laboratory. The fertilized eggs were then implanted into surrogate mothers, resulting in calves with desirable traits like high milk production and disease resistance.

Questions:

  1. In vitro fertilization (IVF) in animal breeding primarily helps in:

    • A) Producing genetically modified animals
    • B) Enhancing desirable traits in animals
    • C) Increasing meat yield
    • D) Reducing breeding costs

    Answer: B) Enhancing desirable traits in animals

  2. Which of the following is a major advantage of in vitro fertilization (IVF) in livestock breeding?

    • A) Increased genetic diversity
    • B) Control over reproductive processes
    • C) Reduced need for artificial insemination
    • D) Improved quality of meat

    Answer: B) Control over reproductive processes

  3. What is the primary goal of artificial insemination (AI) in animal breeding?

    • A) To produce genetically superior offspring
    • B) To reduce the cost of breeding
    • C) To prevent inbreeding in livestock
    • D) To increase genetic diversity in the population

    Answer: A) To produce genetically superior offspring

  4. Which of the following is NOT a benefit of genetic improvement in animals through methods like IVF and AI?

    • A) Increased milk production
    • B) Higher disease resistance
    • C) Improved reproductive efficiency
    • D) Increased biodiversity in animal populations

    Answer: D) Increased biodiversity in animal populations


Case Study 3: Biotechnology and GM Crops

In recent years, genetically modified (GM) crops have gained attention due to their potential to increase food production. One such example is Bt cotton, which has been genetically engineered to express a protein from the bacterium Bacillus thuringiensis. This protein acts as an insecticide, protecting the cotton plants from pests like the cotton bollworm. Farmers growing Bt cotton have reported a reduction in the use of chemical pesticides.

Questions:

  1. The Bt gene used in genetically modified crops like Bt cotton is derived from:

    • A) A virus
    • B) A bacterium
    • C) A fungus
    • D) A mammal

    Answer: B) A bacterium

  2. Bt cotton has been engineered to:

    • A) Resist drought conditions
    • B) Produce an insecticidal protein
    • C) Enhance its resistance to herbicides
    • D) Increase photosynthesis

    Answer: B) Produce an insecticidal protein

  3. Which of the following is a major advantage of growing genetically modified crops like Bt cotton?

    • A) Increased use of chemical pesticides
    • B) Reduced crop yield
    • C) Reduced reliance on chemical pesticides
    • D) Increased soil erosion

    Answer: C) Reduced reliance on chemical pesticides

  4. A concern regarding the widespread adoption of GM crops is:

    • A) Reduced crop resistance to diseases
    • B) Potential environmental impact
    • C) Increased yield
    • D) Lower costs of farming

    Answer: B) Potential environmental impact


Case Study 4: Aquaculture for Fish Production

In coastal regions, the practice of aquaculture has been gaining popularity for increasing fish production. Farmers cultivate fish species like shrimp and tilapia in controlled environments such as ponds or tanks. These systems allow for better control over water quality, food supply, and disease management. However, there are concerns about the environmental impact of intensive aquaculture, including water pollution and the spread of diseases to wild fish populations.

Questions:

  1. Aquaculture is primarily aimed at increasing the production of:

    • A) Vegetables
    • B) Livestock
    • C) Fish and other aquatic organisms
    • D) Fruits

    Answer: C) Fish and other aquatic organisms

  2. Which of the following is NOT a common concern associated with intensive aquaculture?

    • A) Pollution of water bodies
    • B) Spread of diseases to wild populations
    • C) Improved fish quality
    • D) Overexploitation of marine resources

    Answer: C) Improved fish quality

  3. The controlled environment in aquaculture helps in:

    • A) Reducing the risk of diseases
    • B) Increased use of chemical fertilizers
    • C) Ensuring better water quality
    • D) Lowering the cost of feed

    Answer: A) Reducing the risk of diseases

  4. Which of the following is a popular fish species farmed in aquaculture systems?

    • A) Tilapia
    • B) Tuna
    • C) Salmon
    • D) Both A and C

    Answer: D) Both A and C


Case Study 5: Crop Protection and Pest Management

In agricultural fields, integrated pest management (IPM) strategies are used to control pest populations. These strategies combine biological, chemical, and cultural methods. For example, natural predators, such as ladybugs, are introduced to control aphid populations, while chemical pesticides are used sparingly. Farmers also practice crop rotation and use resistant crop varieties to reduce pest build-up.

Questions:

  1. Integrated Pest Management (IPM) includes which of the following methods?

    • A) Only chemical pesticides
    • B) Biological, chemical, and cultural methods
    • C) Only biological methods
    • D) Only crop rotation

    Answer: B) Biological, chemical, and cultural methods

  2. Which of the following is an example of a biological control method in IPM?

    • A) Use of chemical pesticides
    • B) Introducing natural predators like ladybugs
    • C) Burning the crops
    • D) Using genetically modified crops

    Answer: B) Introducing natural predators like ladybugs

  3. The practice of crop rotation helps control pests by:

    • A) Increasing pest resistance
    • B) Reducing pest populations
    • C) Increasing pesticide use
    • D) Increasing crop yield

    Answer: B) Reducing pest populations

  4. One of the advantages of IPM is:

    • A) Complete elimination of pests
    • B) Reduced environmental impact of pesticides
    • C) Increased use of synthetic chemicals
    • D) Higher crop yields without the use of pesticides

    Answer: B) Reduced environmental impact of pesticides