CAIE A Level Biology 9700 · Photosynthesis
A student investigated the effect of light intensity on the rate of photosynthesis using a suspension of chloroplasts and DCPIP. The table shows the time taken for the DCPIP to become colourless at different light intensities.
| Light intensity (arbitrary units) | Decolourisation time (minutes) |
|---|---|
| 10 | 8.0 |
| 20 | 4.0 |
| 40 | 2.5 |
| 80 | 2.5 |
Predict the time taken for the DCPIP to decolourise if the light intensity is increased to 120 arbitrary units. Explain your answer.
4 marks, so the mark scheme is looking for about 4 separate creditworthy points. Making the same point twice in different words earns it once.
Predict means: Say what you expect to happen, using the information given. State the outcome clearly first. If marks remain, add the reason that leads to it.
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