# A muscle cell is damaged during exercise. Describe how mitosis allows the body to replace the damaged muscle cell, and explain why it is important that the new cells produced are identical to the original.

> AQA A-Level Biology (7402) — 3.2.2 Cell Replication · Describe and Explain · 5 marks

## Mark scheme (5 marks)

1. The damaged cell (or a nearby cell) undergoes cell division / mitosis
2. The chromosomes / DNA are copied / replicated before division so each daughter cell receives a full set
3. Two daughter cells are produced that are genetically identical to each other and to the parent cell
4. The new cells are identical so they have the same genes / instructions to carry out the same function as the original muscle cell
5. If the new cells were not identical / had different genetic information, they could not function correctly as muscle cells / could be harmful (e.g. cancer)

## Key terms

- [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 "Describe and 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/a-muscle-cell-is-damaged-during-256afc76) · Published by Druglandscape Ltd.