Two exchange surfaces have the measurements shown in the table. The other factors affecting diffusion are the same for both surfaces.
| Exchange surface | Surface area (cm²) | Concentration difference (arbitrary units) | Membrane thickness (mm) |
|---|---|---|---|
| A | 40 | 3.0 | 0.20 |
| B | 60 | 4.0 | 0.30 |
Calculate the rate of diffusion through surface B as a multiple of the rate through surface A, using Fick's law.
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.