# Explain why cells in the meristem of a plant root tip are able to divide repeatedly, whilst cells in the surrounding root cap are not.

> OCR A-Level Biology A (H420) — 2.6 Cell division, diversity and organisation · Explain · 4 marks

> The root tip of a plant contains two distinct regions: the meristem, a zone of actively dividing undifferentiated cells, and the root cap, a zone of differentiated cells that protect the tip as it pushes through soil. Both regions contain cells that were originally produced from the same parent cells and therefore contain identical DNA.

## Mark scheme (4 marks)

1. Meristem cells remain undifferentiated / are stem cells, so retain the ability to divide by mitosis
2. Root cap cells are differentiated, meaning only specific genes are expressed
3. Both cell types contain the same genes / full genome, but root cap cells do not express the genes required for cell division
4. Differentiation of root cap cells is permanent / irreversible in plants under normal conditions, so they cannot revert to a dividing state

## Key terms

- [meristem](https://www.gradenine.co.uk/glossary/meristem)
- [root cap](https://www.gradenine.co.uk/glossary/root-cap)

## Related

- [Revision notes for OCR A-Level Biology A (H420)](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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-cells-in-the-meristem-3242cd1d) · Published by Druglandscape Ltd.