A disease causes fluid to accumulate between alveolar air and capillary blood. Ventilation maintains the original oxygen concentration difference.
Why does the rate of oxygen diffusion still decrease?
The diffusion distance decreases even though the concentration gradient is maintained.
The oxygen concentration gradient disappears even though the diffusion distance is unchanged.
The oxygen concentration gradient reverses even though the diffusion distance is unchanged.
The diffusion distance increases even though the concentration gradient is maintained.
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.