# Explain why farmers growing crops in greenhouses sometimes pump extra carbon dioxide into the greenhouse and also use artificial lighting at night.

> AQA A-Level Biology (7402) — 3.5.1 Photosynthesis · Explain · 5 marks

## Mark scheme (5 marks)

1. Carbon dioxide is a reactant in / raw material for photosynthesis
2. Increasing carbon dioxide concentration increases the rate of photosynthesis (so more glucose is produced)
3. Light is a reactant / energy source for photosynthesis
4. Artificial lighting at night extends the period during which the plant can photosynthesise / prevents light from being a limiting factor at night
5. Greater rate of photosynthesis means more glucose produced, leading to faster / greater plant growth (increased biomass / yield)

## Key terms

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

## 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-why-farmers-growing-crops-in-cbc7d91c) · Published by Druglandscape Ltd.