# A student cuts a small piece of skin after an accident. New skin cells are produced to repair the damaged area. Explain how the cell cycle produces new skin cells that are genetically identical to the original skin cells.

> Edexcel A-Level Biology A: Salters-Nuffield (9BN0) — 2.2 Cell cycle and mitosis · Explain · 5 marks

> Skin repair requires rapid production of new cells. The cells produced must be genetically identical to the surrounding skin cells so that the tissue functions correctly.

## Mark scheme (5 marks)

1. The cell cycle involves interphase, in which DNA replication occurs so each chromosome is copied
2. During interphase the cell also grows and new organelles are synthesised
3. During mitosis the chromosomes are separated so that each daughter cell receives an identical full set of chromosomes
4. Cytokinesis divides the cytoplasm to produce two new daughter cells
5. The two daughter cells are genetically identical to each other and to the original parent cell because they each contain the same DNA / chromosomes

## Key terms

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

## Related

- [Revision notes for Edexcel A-Level Biology A: Salters-Nuffield (9BN0)](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/a-student-cuts-a-small-piece-5ff010f0) · Published by Druglandscape Ltd.