Sunflower plants were grown at the same temperature and light intensity but with different soil water contents.
| Soil water content (%) | Mean width of stomatal pores (µm) | Rate of carbon dioxide uptake (mg dm⁻² h⁻¹) |
|---|---|---|
| 30 | 8.0 | 24 |
| 20 | 5.0 | 15 |
| 10 | 1.5 | 4 |
Use the data to explain why the rate of photosynthesis decreases as the soil water content decreases. Explain why increasing the light intensity would be unlikely to increase the rate at a soil water content of 10%.
68 exam-style questions on AQA GCSE Biology 4.1 Photosynthesis, covering 4.1.1 Photosynthetic reaction, 4.1.2 Rate of photosynthesis, and 4.1.3 Uses of glucose from photosynthesis. Each one has a worked solution and a mark scheme showing where the marks go.