Describe5 marksChallenge
A student investigated the effect of light intensity on the rate of photosynthesis in the aquatic plant Elodea. The plant was placed in a beaker of water at a constant temperature of 20°C. The light intensity was varied by changing the distance of a lamp from the beaker, and the number of oxygen bubbles released per minute was counted. The results are shown in the table.
| Light intensity (arbitrary units) | Number of bubbles per minute |
|---|---|
| 10 | 8 |
| 20 | 15 |
| 40 | 28 |
| 60 | 38 |
| 80 | 42 |
| 100 | 44 |
| 120 | 45 |
| 150 | 45 |
Describe the effect of light intensity on the rate of photosynthesis in this plant. Explain the shape of the curve obtained, and suggest an investigation to determine which factor is limiting the rate at the highest light intensity used.