A scientist places a moss plant in a sealed transparent chamber. A sensor measures the change in carbon dioxide concentration at different light intensities. A positive value means that the carbon dioxide concentration increased. A negative value means that the carbon dioxide concentration decreased. Temperature and all other conditions are kept constant.
| Light intensity in lux | Change in carbon dioxide concentration in ppm per minute |
|---|---|
| 100 | +0.9 |
| 150 | 0.0 |
Explain why there is no change in carbon dioxide concentration at 150 lux and, using the data, predict how the carbon dioxide concentration is likely to change at 125 lux.
117 exam-style questions on OCR GCSE Biology 1.4 Photosynthesis, covering 1.4.1 Photosynthesisers as biomass producers, 1.4.2 Factors affecting the rate of photosynthesis, and 1.4.3 Limiting factors in photosynthesis. Each one has a worked solution and a mark scheme showing where the marks go.