A grower tests four greenhouse conditions.
The table shows the mean rates of photosynthesis.
Table
| Condition | Temperature in ∘C^\circ\text{C}∘C | Carbon dioxide concentration in % | Light intensity | Rate in arbitrary units |
|---|---|---|---|---|
| W | 15 | 0.04 | low | 3 |
| X | 25 | 0.04 | low | 3 |
| Y | 25 | 0.04 | high | 7 |
| Z | 25 | 0.10 | high | 11 |
The grower claims that extra heating alone must increase photosynthesis, and that extra carbon dioxide has no effect at high light intensity. Which comparisons provide evidence against these two claims, respectively?
W with X; Y with Z.
X with Y; Y with Z.
Y with Z; W with X.
W with X; X with Y.
44 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.