Question 1: Define selective breeding and explain its primary purpose in agriculture.

Answer: Selective breeding is the process of choosing parent organisms with desirable traits to produce offspring with those traits. Its primary purpose is to improve or modify specific characteristics in plants or animals for human benefit.

Question 2: Describe the steps involved in selective breeding of a farm animal, such as cattle.

Answer: The steps include selecting parent animals with desirable traits, controlled mating to ensure these traits are passed on, and selecting the best offspring for further breeding over multiple generations.

Question 3: Which of the following is NOT a reason for using selective breeding? A) To increase crop yield B) To develop disease-resistant plants C) To create genetically identical clones D) To improve livestock quality

Answer: C) To create genetically identical clones

Question 4: Fill in the blank: The process of selecting parents with desirable traits and breeding them to produce offspring with those traits is called __________.

Answer: selective breeding

Question 5: Explain two advantages of using selective breeding in agriculture.

Answer: Advantages include the development of crops and animals that are more productive, disease-resistant, or better suited to specific environments, which can increase food security and reduce the need for chemical treatments.

Question 6: What ethical considerations might arise from selective breeding practices?

Answer: Ethical considerations include concerns about animal welfare, reduced genetic diversity, and potential long-term health problems in selectively bred organisms.

Question 7: In a study, breeders selected for larger fruit size over five generations. The average fruit weight increased from 50g to 80g. Calculate the percentage increase in fruit size.

Answer: Percentage increase = [(Final value - Initial value) / Initial value] x 100 = [(80g - 50g) / 50g] x 100 = (30g / 50g) x 100 = 0.6 x 100 = 60%

Question 8: Identify two potential risks or disadvantages associated with selective breeding.

Answer: Risks include reduced genetic diversity, which can make populations more vulnerable to diseases, and the possibility of unintended health problems or defects in selectively bred organisms.

Question 9: Design a simple experiment to demonstrate how selective breeding can improve a trait in plants. Include independent variable, dependent variable, and safety precautions (theory only).

Answer: An experiment could involve selecting plants with the tallest stems (desirable trait) and cross-breeding them over several generations. The independent variable is the selection criteria (tallest stems), the dependent variable is plant height, and safety precautions include wearing gloves when handling chemicals or soil, and ensuring proper disposal of plant material to prevent contamination.

Question 10: Apply your understanding of selective breeding to a real-world scenario: How might selective breeding be used to develop drought-resistant crops for climate change adaptation?

Answer: Selective breeding can be used to identify and cross plants that naturally survive with less water, gradually enhancing drought tolerance over generations, thus producing crops better suited to changing climate conditions.