# Explain what happens to a plant cell when it is placed in a solution that has a lower water concentration than the cell contents, and explain why the cell does not burst.

> AQA A-Level Biology (7402) — 3.2.3 Transport Across Membranes · Explain · 5 marks

## Mark scheme (5 marks)

1. Water moves out of the cell by osmosis
2. Water moves from an area of higher water concentration (inside the cell) to an area of lower water concentration (in the solution)
3. The cell becomes plasmolysed / the vacuole and cytoplasm shrink / the cell becomes flaccid
4. The cell membrane pulls away from the cell wall (plasmolysis)
5. The cell wall is rigid / inelastic, so it prevents the cell from bursting / the cell wall supports the cell and resists changes in volume

## Key terms

- [water concentration](https://www.gradenine.co.uk/glossary/water-concentration)

## 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/explain-what-happens-to-a-plant-5ac2e28d) · Published by Druglandscape Ltd.