A scientist investigates a sample of marine algae that is photosynthesising in the light.
The table shows the light energy measured during one hour.
| Measurement | Energy (J) |
|---|---|
| Light energy reaching the sample | 1200 |
| Light energy passing through the sample | 420 |
| Light energy reflected by the sample | 60 |
Calculate the light energy absorbed by the sample during the hour.
Explain why the data support the conclusion that photosynthesis is endothermic and what happens to the absorbed energy.
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.