# Explain how the waxy cuticle and the guard cells each help a leaf to reduce water loss whilst still allowing photosynthesis to continue.

> Cambridge International IGCSE Biology (0610) — 6.2 Leaf structure · Explain · 4 marks

## Mark scheme (4 marks)

1. The waxy cuticle reduces water loss by waterproofing the leaf surface
2. The waxy cuticle is transparent / clear, so light can still pass through to reach the palisade mesophyll for photosynthesis
3. Guard cells close the stomata when water supply is limited, reducing water loss through the stomata
4. Closing the stomata reduces carbon dioxide entry, which can limit photosynthesis, so stomata remain open when water is available to allow carbon dioxide in

## Key terms

- [waxy cuticle](https://www.gradenine.co.uk/glossary/waxy-cuticle)
- [guard cells](https://www.gradenine.co.uk/glossary/guard-cells)

## Related

- [Revision notes for Cambridge International IGCSE Biology (0610)](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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-the-waxy-cuticle-and-f2a07973) · Published by Druglandscape Ltd.