A crop is grown in a controlled room. A scientist changes one condition at a time and measures the rate of oxygen production. The results are shown in the table.
| Test | Light intensity (relative units) | Carbon dioxide concentration (%) | Temperature (°C) | Rate of oxygen production (cm³ min⁻¹) |
|---|---|---|---|---|
| 1 | 100 | 0.04 | 20 | 5 |
| 2 | 200 | 0.04 | 20 | 9 |
| 3 | 200 | 0.10 | 20 | 9 |
| 4 | 200 | 0.10 | 30 | 15 |
| 5 | 200 | 0.10 | 40 | 6 |
Explain what the results show about the interaction of light intensity, carbon dioxide concentration and temperature in limiting the rate of photosynthesis. Explain the likely effect on the rate in test 3 of increasing the carbon dioxide concentration to 0.20%.
87 exam-style questions on Edexcel GCSE Biology 6.1 Photosynthesis, covering 6.1.1 Photosynthetic organisms as producers, 6.1.2a Limiting factors on the rate of photosynthesis, 6.1.2b Interactions of limiting factors on photosynthesis, and 6.1.3 Inverse square law and light intensity. Each one has a worked solution and a mark scheme showing where the marks go.