# Describe the role of stomata in the excretion of waste gases from the leaves of a flowering plant.

> Pearson Edexcel International GCSE Biology (4BI1) — 2.12 Excretion: flowering plants · Describe · 4 marks

> Flowering plants produce waste gases as by-products of metabolism. These gases must be removed from the plant body.

## Mark scheme (4 marks)

1. Carbon dioxide is a waste product of (aerobic) respiration in flowering plants
2. Oxygen is a waste product of photosynthesis in flowering plants
3. Waste gases move out of the leaf by diffusion (through the stomata)
4. Stomata are pores / openings (in the leaf surface / epidermis) that allow gas exchange / that open and close to control the movement of gases

## Key terms

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

## Related

- [Revision notes for Pearson Edexcel International GCSE Biology (4BI1)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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/describe-the-role-of-stomata-in-30ded5db) · Published by Druglandscape Ltd.