CAIE A Level Biology 9700 · Cell membranes and transport
A student measured the change in mass of potato cylinders after immersion in sucrose solutions of different concentrations. The table shows the results.
| Sucrose concentration / mol dm | Percentage change in mass |
|---|---|
| 0.0 | +15 |
| 0.2 | +8 |
| 0.4 | 0 |
| 0.6 | -5 |
| 0.8 | -12 |
| 1.0 | -18 |
Describe how the student could use these results to estimate the water potential of the potato tissue.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
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