# A scientist is researching stem cells to develop new treatments for diseases. Explain why stem cells are useful in medicine and describe how they can be used to treat patients with damaged tissues.

> OCR A-Level Biology B — Advancing Biology (H422) — 3.1 Cell division and stem cells · Explain · 5 marks

> Stem cells are unspecialised cells found in embryos and in some adult tissues. Researchers believe stem cells could be used to replace damaged or diseased cells in a range of medical conditions, including those affecting the nervous system and blood.

## Mark scheme (5 marks)

1. Stem cells are unspecialised / undifferentiated cells
2. Stem cells can differentiate into many / different types of specialised cells
3. Stem cells can be used to replace damaged or diseased cells / tissues in the body
4. Embryonic stem cells can differentiate into any cell type (are pluripotent) OR adult stem cells are found in bone marrow and can differentiate into blood cells
5. There are ethical concerns / risks associated with stem cell use, e.g. use of embryos raises ethical issues OR risk of rejection / infection

## Key terms

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

## Related

- [Revision notes for OCR A-Level Biology B — Advancing Biology (H422)](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-scientist-is-researching-stem-cells-af28e6cf) · Published by Druglandscape Ltd.