# Explain how mutations and sexual reproduction contribute to genetic variation within a population.

> Cambridge International IGCSE Biology (0610) — 18.1 Variation · Explain · 4 marks

## Mark scheme (4 marks)

1. Mutation causes a random change in the base sequence of DNA
2. New alleles formed by mutation increase genetic variation between individuals
3. During meiosis, gametes are produced each with a different combination of alleles
4. Fusion of two different gametes at fertilisation produces offspring with a new, unique combination of alleles / genotype

## Key terms

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

## Related

- [Revision notes for Cambridge International IGCSE Biology (0610)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-mutations-and-sexual-reproduction-bda441d8) · Published by Druglandscape Ltd.