# Explain why a population of organisms that reproduces only by mitosis is less likely to survive a new disease compared to a population of the same species that reproduces by meiosis.

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

## Mark scheme (5 marks)

1. Mitosis produces genetically identical cells / clones
2. So all individuals in the mitosis-only population are genetically identical / have the same genes
3. Meiosis produces gametes / offspring with genetic variation
4. Some individuals in the meiosis population may have alleles / mutations that give resistance to the disease
5. Those resistant individuals survive and reproduce, passing on the resistance allele / the population survives whereas the clonal population would all die

## Key terms

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

## 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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-a-population-of-organisms-b5b13071) · Published by Druglandscape Ltd.