Predict7 marksChallenge
An investigation measured the rate of photosynthesis in a plant leaf at different light intensities and carbon dioxide concentrations. The temperature was kept constant at 20°C. The results are shown in the table.
| Light intensity (μmol m⁻² s⁻¹) | CO₂ concentration (ppm) | Rate of photosynthesis (μmol CO₂ m⁻² s⁻¹) |
|---|---|---|
| 50 | 300 | 2 |
| 50 | 600 | 2 |
| 100 | 300 | 4 |
| 100 | 600 | 4 |
| 200 | 300 | 4 |
| 200 | 600 | 8 |
(a) Predict which factor is limiting the rate at a light intensity of 50 μmol m⁻² s⁻¹ and CO₂ concentration of 300 ppm. Explain how the data support your prediction.
(b) Predict which factor is limiting the rate at a light intensity of 200 μmol m⁻² s⁻¹ and CO₂ concentration of 300 ppm. Explain how the data support your prediction.
(c) State one other factor that could become limiting if both light intensity and CO₂ concentration are increased sufficiently.