# Explain how a mutation in a gene may lead to a change in the phenotype of an organism.

> Eduqas GCSE Biology — 2.4.1 Variation · Explain · 4 marks

## Mark scheme (4 marks)

1. A mutation is a random change in the DNA (base sequence) of a gene.
2. A change in the base sequence alters the sequence of amino acids coded for (via the triplet code).
3. A different amino acid sequence produces a different (or non-functional) protein.
4. A change in the protein produced leads to a change in the characteristic / phenotype of the organism.

## Key terms

- [mutation](https://www.gradenine.co.uk/glossary/mutation)
- [gene](https://www.gradenine.co.uk/glossary/gene)
- [phenotype](https://www.gradenine.co.uk/glossary/phenotype)

## Related

- [Revision notes for Eduqas GCSE Biology](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/explain-how-a-mutation-in-a-2802e22d) · Published by Druglandscape Ltd.