Describe how selective breeding could be used to produce a breed of cattle that yields a large amount of milk. Include in your answer the steps involved in the selective breeding process.

Edexcel GCSE Biology (1BI0) — 4.3 Selective breeding and genetic engineering · Describe · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

A farmer wants to improve the milk yield of their cattle herd over several generations. The farmer decides to use selective breeding to achieve this.

Model answer (4 marks)

1. Identify the cattle that give the highest milk yield and select them as parents.
2. Breed the selected high‑yield cattle with each other.
3. From the resulting offspring, select those that have the highest milk yield and breed them again.
4. Repeat the selection and breeding over many generations; after several generations the herd will consistently produce higher milk yields.

Examiner tips

  • Use the word "select" and "breed" clearly; show the cycle of selection and breeding.
  • Mention that the process is repeated over many generations to achieve a stable trait.

Common mistakes

  • Not stating that the selection is based on milk yield.
  • Failing to mention that the process is repeated over several generations.

Mark scheme (4 marks)

  1. Identify and select cattle with the highest milk yield as parents
  2. Breed the selected cattle with each other
  3. Select offspring with the highest milk yield and breed them again / repeat the process over many generations
  4. Over time / after many generations, the herd will produce offspring with a consistently higher milk yield

Key terms in this question

selective breeding

Related

More Selective breeding and genetic engineering questions

▶ Try answering this question with AI marking (free) →