Fick's law states that diffusion rate is proportional to surface area when other factors are constant.
A membrane area increases from 4 cm2 to 12 cm2. All other factors remain constant.
How does the diffusion rate change?
It becomes one third of the original rate.
It becomes four times the original rate.
It becomes one quarter of the original rate.
It becomes three times the original rate.
42 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.