A technician measures oxygen production by a culture of microalgae during three trials.
The conditions and results are shown in the table.
| Trial | Light intensity in W m−2\text{W m}^{-2}W m−2 | Temperature in ∘C^\circ\text{C}∘C | Carbon dioxide concentration in % | Rate of oxygen production in cm3 min−1\text{cm}^3\ \text{min}^{-1}cm3 min−1 |
|---|---|---|---|---|
| J | 50 | 25 | 0.10 | 0.8 |
| K | 100 | 25 | 0.10 | 1.6 |
| L | 50 | 30 | 0.10 | 0.8 |
Which conclusion is supported by the data?
Doubling the light intensity has no effect when the temperature is 25 ∘C25\ ^\circ\text{C}25 ∘C.
The algae in trial J could photosynthesise faster if given more light.
Warming the algae from 25 ∘C25\ ^\circ\text{C}25 ∘C to 30 ∘C30\ ^\circ\text{C}30 ∘C would speed up trial J.
The unchanged rate in trials J and L shows that carbon dioxide is limiting.
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.