Two lung conditions are described in the table.
Table
| Condition | Change from a healthy lung |
|---|---|
| P | Some alveolar walls are lost, reducing total exchange area. |
| Q | Alveolar walls become thicker, with no change in exchange area. |
Which statement identifies the cause of reduced oxygen uptake in both conditions?
P increases the distance for diffusion; Q reduces the area for diffusion.
P reduces the area for diffusion; Q decreases the distance for diffusion.
P reduces the area for diffusion; Q increases the distance for diffusion.
P decreases the distance for diffusion; Q reduces the area for diffusion.
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.