Contents
Key Stage 3
Meaning
Stomata are holes in the leaf that can open and close to allow or stop gas exchange in the leaf.
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| The under side of a leaf showing guard cells and stomata. |
About Stomata
- There are usually more stomata on the underside of a leaf than the top side.
- Stomata close when the leaf becomes dehydrated. This stops photosynthesis, which needs water, so it helps stop the dehydration from getting worse.
The Process:
- 1. Plant becomes dehydrated.
- 2. Guard Cells become flaccid.
- 3. Stomata close.
- 4. Carbon Dioxide can no longer enter the leaf.
- 5. Photosynthesis stops.
- 6. Respiration continues to make water and water is taken up by the roots.
- 7. Plant becomes hydrated again.
- 8. Guard Cells become turgid.
- 9. Stomata open.
- 10. Carbon Dioxide can now get into the leaf.
- 11. Photosynthesis starts again using up the water.
References
AQA
- Stomata, page 55, GCSE Biology; Student Book, Collins, AQA
- Stomata, pages 22, 38, 40, GCSE Combined Science; The Revision Guide, CGP, AQA
- Stomata, pages 23, 66-68, GCSE Biology; Third Edition, Oxford University Press, AQA
- Stomata, pages 297, 301, GCSE Chemistry; Student Book, Collins, AQA
- Stomata, pages 60, 86, 88, 89, GCSE Combined Science Trilogy; Biology, CGP, AQA
- Stomata, pages 60-1, 68, 70-1, GCSE Biology; Student Book, Collins, AQA
- Stomata, pages 66, 92, 94, 95, GCSE Biology, CGP, AQA
- Stomata, pages 68-9, GCSE Combined Science Trilogy 1, Hodder, AQA
- Stomata, pages, 25, 44, GCSE Biology; The Revision Guide, CGP, AQA
Edexcel
- Stomata (singular stoma), page 125, GCSE Biology, Pearson, Edexcel
- Stomata, page 50, GCSE Combined Science; The Revision Guide, CGP, Edexcel
- Stomata, pages 211-214, GCSE Biology, CGP, Edexcel
- Stomata, pages 72, 73, GCSE Biology; The Revision Guide, CGP, Edexcel