# Salmon farmers want to produce a strain of salmon that grows more quickly than wild salmon. Explain how selective breeding could be used to produce this faster-growing strain of salmon.

> Pearson Edexcel International GCSE Biology (4BI1) — 5.2 Selective breeding · Explain · 4 marks

## Mark scheme (4 marks)

1. Select/identify salmon that show the fastest growth (from the existing population)
2. Breed the selected (fastest-growing) salmon with each other / interbreed the selected individuals
3. Select the fastest-growing offspring and repeat the process over many generations
4. Until offspring consistently / reliably show the desirable phenotype (fast growth) / the strain breeds true for fast growth

## Key terms

- [selective breeding](https://www.gradenine.co.uk/glossary/selective-breeding)

## Related

- [Revision notes for Pearson Edexcel International GCSE Biology (4BI1)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/salmon-farmers-want-to-produce-a-ac458488) · Published by Druglandscape Ltd.