# Explain why mutations are important for the long-term survival of a species in a changing environment.

> AQA A-Level Biology (7402) — 3.4.3 Mutation and Meiosis · Explain · 5 marks

> Mutations are random changes to DNA. Most mutations have no effect on the organism, but occasionally a mutation produces a new allele that alters the phenotype of an organism.

## Mark scheme (5 marks)

1. Mutations produce new alleles (or new variants of genes)
2. This increases genetic variation within the population
3. If the environment changes, some individuals may have a phenotype (caused by the mutation) that is better suited / adapted to the new conditions
4. Those individuals are more likely to survive and reproduce, passing the advantageous allele to offspring (natural selection)
5. Over many generations the frequency of the advantageous allele increases in the population, helping the species survive

## Key terms

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

## Related

- [Revision notes for AQA A-Level Biology (7402)](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-why-mutations-are-important-for-ffac9913) · Published by Druglandscape Ltd.