# Describe how the rate of photosynthesis in a plant would change if carbon dioxide concentration in the air gradually increased. Explain why this change occurs.

> Eduqas GCSE Biology — 1.5.2 Photosynthesis · Describe · 4 marks

> A plant is growing in a sealed greenhouse. Over several hours, the concentration of carbon dioxide inside the greenhouse slowly rises.

## Mark scheme (4 marks)

1. The rate of photosynthesis increases (as carbon dioxide concentration rises)
2. Carbon dioxide is a reactant / raw material used in photosynthesis
3. More carbon dioxide available means more reactions can take place / more glucose can be produced
4. The rate will eventually level off / stop increasing because another factor becomes limiting (e.g. light intensity or temperature)

## Key terms

- [photosynthesis](https://www.gradenine.co.uk/glossary/photosynthesis)
- [carbon dioxide](https://www.gradenine.co.uk/glossary/carbon-dioxide)
- [rate of photosynthesis](https://www.gradenine.co.uk/glossary/rate-of-photosynthesis)

## Related

- [Revision notes for Eduqas GCSE Biology](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-how-the-rate-of-photosynthesis-82a33278) · Published by Druglandscape Ltd.