Describe how a farmer could use selective breeding to produce a herd of cattle that gives more milk than the current herd.

Eduqas GCSE Biology — 7.4 Selective breeding and gene technology · Describe · 4 marks · View as Markdown

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

A farmer has a herd of cattle. Some individuals in the herd naturally produce more milk than others. The farmer wants to increase the milk yield of the whole herd over several generations.

Model answer (4 marks)

Identify and select cattle that naturally produce the highest milk yield as parents. Breed these selected individuals together. From the offspring, choose those with the greatest milk yield and use them as parents for the next generation. Repeat this selection and breeding cycle over many generations, gradually increasing the average milk yield of the herd.

Examiner tips

Use the word ‘select’ and ‘breed’ to show the process.
Show the cycle of selecting parents, breeding, and re‑selecting offspring.
Mention that the improvement occurs over several generations.
Use UK spelling (e.g., ‘herd’).

Common mistakes

Failing to mention that the process is repeated over many generations.
Using vague terms like ‘improve’ without describing selection and breeding steps.
Mixing up the order of selection and breeding (e.g., breeding first then selecting).

Mark scheme (4 marks)

Identify and select cattle with the desired characteristic (high milk yield) as parents
Breed the selected individuals together
Select the offspring with the highest milk yield from the next generation and repeat the process
Over many generations, the milk yield of the herd increases

Key terms in this question

selective breeding