# Explain how osmosis moves water into a plant root hair cell when the cell is surrounded by soil water.

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

> Root hair cells have a large surface area and are in contact with water in the soil. The cell contents of a root hair cell contain dissolved minerals and sugars.

## Mark scheme (5 marks)

1. Osmosis is the movement of water molecules
2. through a partially permeable membrane
3. The soil water has a higher water concentration than the cell contents (or the cell contents have a lower water concentration than the soil water)
4. Water moves from a region of higher water concentration (soil water) to a region of lower water concentration (inside the cell)
5. The dissolved minerals / sugars inside the cell reduce the water concentration of the cell contents (explaining why the gradient exists)

## Key terms

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

## 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-how-osmosis-moves-water-into-11c2f39c) · Published by Druglandscape Ltd.