# Describe the role of limiting factors in photosynthesis. In your answer, give two examples of limiting factors and explain how each one limits the rate of photosynthesis.

> AQA GCSE Biology (8461) — 4.4.1 Photosynthesis · Describe · 4 marks

## Mark scheme (4 marks)

1. A limiting factor is a factor that limits the rate of photosynthesis when there is not enough of it
2. Names light intensity as a limiting factor
3. Explains how the named first factor (e.g. light intensity) limits the rate — e.g. low light intensity means less energy is transferred to the chloroplasts so the rate of photosynthesis decreases
4. Names a second limiting factor (e.g. carbon dioxide concentration or temperature) AND explains how it limits the rate — e.g. low CO₂ concentration means less raw material is available so the rate of photosynthesis decreases

## Key terms

- [limiting factor](https://www.gradenine.co.uk/glossary/limiting-factor)
- [photosynthesis](https://www.gradenine.co.uk/glossary/photosynthesis)

## Related

- [Revision notes for AQA GCSE Biology (8461)](https://www.gradenine.co.uk/learn)
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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-the-role-of-limiting-factors-23f9770a) · Published by Druglandscape Ltd.