A reference group, R, and four test groups contain the same number and type of animal cells. Each group is placed in a solution. The temperature is constant, and the cells in each group have the same total membrane surface area and membrane thickness.
The initial dissolved oxygen concentrations are shown in the table.
| Group | Oxygen concentration in solution in mmol dm−3\mathrm{mmol\,dm^{-3}}mmoldm−3 | Oxygen concentration in cells in mmol dm−3\mathrm{mmol\,dm^{-3}}mmoldm−3 |
|---|---|---|
| R | 0.28 | 0.12 |
| W | 0.26 | 0.10 |
| X | 0.21 | 0.09 |
| Y | 0.25 | 0.15 |
| Z | 0.12 | 0.28 |
Which test group has the same initial net rate of oxygen diffusion into the cells as group R?
Group X has the same initial net rate as group R.
Group Z has the same initial net rate as group R.
Group W has the same initial net rate as group R.
Group Y has the same initial net rate as group R.
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.