A researcher uses a transparent hood to measure photosynthesis by leaves in a field. Air flows through the hood. A gas analyser measures the total volume of carbon dioxide entering and leaving the hood during a sampling period.
| Total leaf area in m2\mathrm{m^2}m2 | Carbon dioxide entering in cm3\mathrm{cm^3}cm3 | Carbon dioxide leaving in cm3\mathrm{cm^3}cm3 | Sampling time in minutes |
|---|---|---|---|
| 2.0 | 360 | 300 | 5 |
Calculate the mean rate of carbon dioxide uptake per minute per square metre of leaf area. Use this rate to predict the volume of carbon dioxide taken up by another group of leaves with a total leaf area of 3.5 m2 in 8 minutes.
Assume that the mean rate of carbon dioxide uptake per square metre is unchanged and that enough carbon dioxide passes through the hood.
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.