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

Answer: Selective breeding is the process of choosing parent organisms with desirable traits to produce offspring that inherit those traits, aiming to enhance specific characteristics in future generations.

Question 1: Describe the main steps involved in the process of selective breeding.

Answer: The main steps are: 1. Identify organisms with desirable traits, 2. Select the best individuals to breed, 3. Breed these selected organisms, 4. Repeat the process over several generations to enhance traits.

Question 2: Explain why genetic diversity might decrease as a result of selective breeding.

Answer: Because selective breeding often involves choosing a limited number of organisms with specific traits, reducing the overall genetic variation in the population.

Question 1: A farmer selects 10 bulls, of which 4 carry a desirable coat colour gene. If the farmer breeds these bulls with 20 cows, what is the probability that a randomly selected calf inherits the gene assuming the bulls are heterozygous for the trait? (Use Punnett square principles.)

Answer: The probability is 25%. Explanation: If bulls are heterozygous (Aa), and cows are unaffected (aa), then each calf has a 50% chance of inheriting the dominant allele from the bull. Since 4 out of 10 bulls carry the gene, the overall probability is (4/10) * 0.5 = 0.2 or 20%.

Question 1: List three important safety or ethical considerations when performing selective breeding programmes.

Answer: Ensuring animal welfare, avoiding reduced genetic diversity leading to health problems, and preventing the loss of wild genetic traits.

Question 2: Identify two variables that must be controlled during a selective breeding experiment.

Answer: Environmental conditions and age of the organisms used for breeding.

Question 1: In a population of 200 chickens, 150 have a desirable feather colour, and 50 do not. The next generation shows 180 with the desirable trait and 20 without. Discuss what these data suggest about the effectiveness of selective breeding in this case.

Answer: The increase from 150 to 180 chickens with the desirable trait suggests that selective breeding is effective, promoting the trait's prevalence. The reduction of non-desirable traits from 50 to 20 indicates successful selection over generations, although some variation remains. This demonstrates the potential to enhance desired characteristics through selective breeding.

Question 1: Explain how selective breeding has been used to improve crop yields in agriculture.

Answer: Selective breeding has been used to develop crop varieties with higher yields, resistance to pests and diseases, and tolerance to environmental stresses by choosing plants with these traits to produce the next generation.

Question 2: Discuss a potential ethical concern associated with using selective breeding in animals.

Answer: A concern is that selective breeding can lead to health problems in animals, such as reduced genetic diversity and inherited diseases, raising ethical questions about animal welfare.