# A scientist is comparing two types of stem cells. Explain the differences between embryonic stem cells and adult stem cells, and suggest why embryonic stem cells are considered more useful for medical treatments.

> OCR A-Level Biology B — Advancing Biology (H422) — 2.1 Cell structure · Explain · 5 marks

> Stem cells are used in medical research and treatment. Scientists can obtain stem cells from two main sources: early embryos and bone marrow.

## Mark scheme (5 marks)

1. Embryonic stem cells can differentiate into any cell type (are pluripotent)
2. Adult stem cells are found in bone marrow and can only form many (but not all) types of cells
3. Both are undifferentiated / unspecialised cells capable of differentiating
4. Embryonic stem cells are more useful because they can be used to produce a wider range of specialised cells / tissues for treatment
5. Adult stem cells are limited in the range of cell types they can produce, making them less versatile for medical treatments

## Key terms

- [embryonic stem cell](https://www.gradenine.co.uk/glossary/embryonic-stem-cell)
- [adult stem cell](https://www.gradenine.co.uk/glossary/adult-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-comparing-two-types-47f195f7) · Published by Druglandscape Ltd.