# Explain why a cell in the metaphase of mitosis has twice the DNA content of a cell that has just completed cytokinesis.

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

> Mitosis is a form of cell division that produces two genetically identical daughter cells. The process is divided into distinct stages, each characterised by specific events involving the chromosomes and the cell.

## Mark scheme (4 marks)

1. DNA replication occurs during S phase of interphase, before mitosis begins
2. At metaphase the replicated chromosomes (consisting of two sister chromatids) are present but have not yet separated
3. During anaphase/telophase the sister chromatids are separated and pulled to opposite poles, halving the DNA content at each pole
4. Cytokinesis divides the cytoplasm so each daughter cell receives one set of chromatids, giving the original (unreplicated) DNA content

## Key terms

- [metaphase](https://www.gradenine.co.uk/glossary/metaphase)
- [mitosis](https://www.gradenine.co.uk/glossary/mitosis)
- [cytokinesis](https://www.gradenine.co.uk/glossary/cytokinesis)
- [DNA content](https://www.gradenine.co.uk/glossary/dna-content)

## 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-a-cell-in-the-76f6fe31) · Published by Druglandscape Ltd.