# Describe how the structure of a leaf is adapted to allow efficient photosynthesis. Include in your answer the roles of the palisade mesophyll, spongy mesophyll, and upper epidermis.

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

## Mark scheme (4 marks)

1. Palisade mesophyll is positioned near the top of the leaf / close to the upper surface where most light strikes, so it can absorb the maximum amount of light energy
2. Palisade mesophyll cells contain many chloroplasts to carry out photosynthesis
3. Spongy mesophyll has air spaces that increase the surface area, allowing rapid diffusion of carbon dioxide (and oxygen) for photosynthesis
4. Upper epidermis cells are transparent, allowing light to pass through to the palisade mesophyll below

## Key terms

- [palisade mesophyll](https://www.gradenine.co.uk/glossary/palisade-mesophyll)
- [spongy mesophyll](https://www.gradenine.co.uk/glossary/spongy-mesophyll)
- [upper epidermis](https://www.gradenine.co.uk/glossary/upper-epidermis)

## Related

- [Revision notes for Cambridge International IGCSE Biology (0610)](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-how-the-structure-of-a-44b85892) · Published by Druglandscape Ltd.