# A student says: 'When a cell divides by mitosis, the DNA must be copied before division can occur.' Explain why the student is correct, and describe what happens to the chromosomes during mitosis to ensure each daughter cell receives the correct genetic information.

> AQA A-Level Biology (7402) — 3.2.2 Cell Replication · Explain · 5 marks

## Mark scheme (5 marks)

1. DNA replication occurs before mitosis / in the cell cycle before division
2. This ensures there is enough DNA / a full set of chromosomes to pass to each daughter cell
3. The chromosomes line up along the middle / equator of the cell
4. The copies of each chromosome are pulled to opposite ends / poles of the cell
5. Two daughter cells are produced, each with the same number of chromosomes as the parent cell / genetically identical to the parent cell

## Key terms

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

## Related

- [Revision notes for AQA A-Level Biology (7402)](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-student-says-when-a-cell-68da4290) · Published by Druglandscape Ltd.