A student investigates the effect of temperature on diffusion through an artificial membrane. The membrane is permeable to substance X and its permeability does not change with temperature.
Table
| Investigation | Temperature / ∘C^\circ\text{C}∘C | Initial concentration of X on side P / arbitrary units | Initial concentration of X on side Q / arbitrary units |
|---|---|---|---|
| 1 | 15 | 8 | 2 |
| 2 | 25 | 8 | 2 |
| 3 | 15 | 8 | 4 |
| 4 | 25 | 6 | 4 |
All other conditions are the same.
Which comparison isolates the effect of temperature, and what result is expected?
compare 1 and 2; the initial net rate is greater in 2
compare 1 and 2; the initial net rate is greater in 1
compare 3 and 4; the initial net rate is greater in 4
compare 3 and 4; the initial net rate is greater in 3
41 exam-style questions on Edexcel GCSE Biology 1.4 Transport across cell membranes, covering 1.4.1 Transport into and out of cells and 1.4.2 Percentage gain and loss in osmosis. Each one has a worked solution and a mark scheme showing where the marks go.