Question 1

What is selective breeding and how is it used in agriculture?

Accepted Answer

Selective breeding, also known as artificial selection, is a process where humans intentionally breed plants or animals for specific traits. In agriculture, it is used to enhance desirable characteristics such as increased yield, disease resistance, or improved nutritional value. This method involves choosing parent organisms with favorable traits to produce offspring that inherit these traits, thereby improving the quality and productivity of crops and livestock.

Question 2

How does selective breeding differ from natural selection?

Accepted Answer

Selective breeding differs from natural selection in that it is a human-directed process, whereas natural selection is a natural process driven by environmental pressures. In selective breeding, humans choose which traits are desirable and breed individuals that exhibit those traits. In contrast, natural selection occurs without human intervention, where organisms with traits better suited to their environment are more likely to survive and reproduce, passing those traits to the next generation.

Question 3

What are some examples of selective breeding in animals?

Accepted Answer

Selective breeding in animals has led to the development of various breeds with specific traits. For example, dairy cows have been selectively bred for higher milk production, while chickens have been bred for increased egg-laying capacity. In dogs, selective breeding has resulted in a wide variety of breeds with different sizes, temperaments, and abilities, such as herding or hunting skills.

Question 4

What are the potential drawbacks of selective breeding?

Accepted Answer

While selective breeding can produce desirable traits, it also has potential drawbacks. One major concern is the reduction of genetic diversity, which can make populations more susceptible to diseases and environmental changes. Additionally, focusing on specific traits can sometimes lead to unintended health issues, such as hip dysplasia in certain dog breeds or reduced fertility in livestock.

Question 5

How is selective breeding covered in the Edexcel IGCSE Biology curriculum?

Accepted Answer

In the Edexcel IGCSE Biology curriculum, selective breeding is covered under the topic 'Use of Biological Resources.' Students learn about the principles and applications of selective breeding in agriculture and animal husbandry, as well as its advantages and disadvantages. The curriculum emphasizes understanding the impact of selective breeding on genetic variation and the ethical considerations involved in manipulating biological resources.

Selective Breeding

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