# Explain how active transport allows a plant root hair cell to absorb mineral ions from the soil, even when the concentration of mineral ions in the soil water is lower than inside the cell.

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

## Mark scheme (5 marks)

1. Active transport moves mineral ions against a concentration gradient (from low to high concentration)
2. Active transport requires energy (in the form of ATP / released from respiration)
3. Carrier proteins in the cell membrane are used to transport the mineral ions into the cell
4. The mineral ions move from the soil water into the root hair cell
5. This allows the plant to absorb ions it needs even when their concentration is already higher inside the cell than in the soil

## Key terms

- [active transport](https://www.gradenine.co.uk/glossary/active-transport)
- [mineral ions](https://www.gradenine.co.uk/glossary/mineral-ions)

## 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-active-transport-allows-a-c65e0d32) · Published by Druglandscape Ltd.