# Cancer can develop when cells undergo uncontrolled growth and division. Explain how a mutation in a cell's DNA can lead to the formation of a tumour, and describe one risk and one benefit of using stem cell therapy to treat cancer patients.

> Eduqas A-Level Biology — 1.6 Cell division · Explain · 5 marks

## Mark scheme (5 marks)

1. A mutation causes a change in the cell's DNA
2. The mutation leads to uncontrolled growth and division of cells
3. This produces a large amount of unwanted cells, forming a tumour
4. One valid risk of stem cell therapy (e.g. contamination or mutation of stem cells whilst being grown in the laboratory which could be passed to the patient; long-term risks are unknown / no guarantee the treatment will work; side effects such as rashes, infections or bleeding)
5. One valid benefit of stem cell therapy (e.g. stem cells are not rejected unlike donor organs; stem cells do not have to be matched to the patient; can treat a large variety of diseases; generally lower risks than other treatments)

## Key terms

- [mutation](https://www.gradenine.co.uk/glossary/mutation)
- [uncontrolled growth and division](https://www.gradenine.co.uk/glossary/uncontrolled-growth-and-division)
- [tumour](https://www.gradenine.co.uk/glossary/tumour)
- [stem cell therapy](https://www.gradenine.co.uk/glossary/stem-cell-therapy)
- [cancer](https://www.gradenine.co.uk/glossary/cancer)

## Related

- [Revision notes for Eduqas A-Level Biology](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/cancer-can-develop-when-cells-undergo-aec2df59) · Published by Druglandscape Ltd.