A student measured the rate at which a dye diffused through agar jelly at four different concentration differences. The table shows the results. Which conclusion is supported by the data in the table?
Table: The rate of diffusion of a dye through agar jelly at four different concentration differences
| Concentration difference in arbitrary units | Rate of diffusion in mm per hour |
|---|---|
| 2 | 1.4 |
| 4 | 2.8 |
| 6 | 4.2 |
| 8 | 5.6 |
The rate of diffusion is directly proportional to the concentration difference.
The rate of diffusion increases by a smaller amount at each concentration difference.
The rate of diffusion doubles each time the concentration difference increases.
The rate of diffusion is the same at each of the concentration differences tested.
140 exam-style questions on AQA GCSE Biology 1.3 Transport in cells, covering 1.3.1 Diffusion, 1.3.2 Osmosis, and 1.3.3 Active transport. Each one has a worked solution and a mark scheme showing where the marks go.