A student tests whether rate of photosynthesis is proportional to light intensity. Temperature and carbon dioxide concentration are controlled.
The table shows the results.
Table
| Distance from lamp in cm | Gas volume in cm3\text{cm}^3cm3 | Collection time in minutes |
|---|---|---|
| 15 | 9.6 | 4 |
| 30 | 3.0 | 5 |
Which statement correctly compares the rate ratio with the light intensity ratio?
The ratios are 2 : 1 and 4 : 1, respectively.
Both ratios are 4 : 1, supporting direct proportionality.
Both ratios are 2 : 1, supporting direct proportionality.
The ratios are 4 : 1 and 2 : 1, respectively.
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.