# Explain how auxin causes a plant shoot to grow towards a light source.

> AQA GCSE Biology (8461) — 4.5.4 Plant hormones (Bio only) · Explain · 4 marks

## Mark scheme (4 marks)

1. Auxin is produced at the tip of the shoot and moves/distributes to the shaded side
2. Auxin causes cells to elongate / grow longer on the shaded side
3. The shaded side grows faster/longer than the light side
4. This unequal growth causes the shoot to bend / curve towards the light

## Key terms

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

## Related

- [Revision notes for AQA GCSE Biology (8461)](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-auxin-causes-a-plant-40a5e2ef) · Published by Druglandscape Ltd.