A laboratory grows animal cells beside an oxygen-permeable membrane. Oxygen diffuses through the membrane to the cells. The concentration difference across the membrane remains constant.
| Membrane property | Before the change | After the change |
|---|---|---|
| surface area | 18 cm2 | 45 cm2 |
| thickness | 0.30 mm | 0.20 mm |
Calculate how many times greater the rate of oxygen diffusion is after the membrane is changed.
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.