# Explain why cells in the meristem of a plant root tip divide by mitosis rather than meiosis, and describe one feature of the cell cycle that ensures each daughter cell receives the correct number of chromosomes.

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

> Plant roots grow by producing new cells at the root tip. A region called the meristem contains rapidly dividing cells that are responsible for this growth. These cells are diploid and must remain genetically identical to the parent cell.

## Mark scheme (4 marks)

1. Mitosis is used because the daughter cells must be genetically identical to the parent cell / for growth and repair, not sexual reproduction
2. Meiosis would produce haploid cells, so the daughter cells would no longer be diploid / would have the wrong chromosome number for somatic cells
3. DNA replication (during S phase / interphase) ensures each chromosome is copied so there is sufficient genetic material to be distributed equally
4. During mitosis, spindle fibres attach to centromeres and pull sister chromatids to opposite poles, ensuring each daughter cell receives one copy of each chromosome

## Key terms

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

## 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)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-cells-in-the-meristem-116d2e61) · Published by Druglandscape Ltd.