Carbon dioxide diffuses from four respiring plant root cells into the surrounding fluid. The cells have identical surface areas and membrane thicknesses, and are at the same temperature.
| Cell | Carbon dioxide concentration inside the cell (mmol/dm³) | Carbon dioxide concentration in the surrounding fluid (mmol/dm³) |
|---|---|---|
| A | 1.2 | 0.4 |
| B | 1.0 | 0.2 |
| C | 0.9 | 0.4 |
| D | 1.4 | 0.2 |
Which pair of cells has the same initial net rate of carbon dioxide diffusion out of the cells?
cells A and B
cells C and D
cells B and D
cells A and C
102 exam-style questions on Edexcel GCSE Biology 8.1 Exchange surfaces and diffusion, covering 8.1.1 Introduction to exchange and transport, 8.1.2 Alveoli adapted for gas exchange, 8.1.3 Factors affecting rate of diffusion, and 8.1.4 Rate of diffusion using Fick's law. Each one has a worked solution and a mark scheme showing where the marks go.