A disease destroys some walls between adjacent alveoli. Several small air spaces become one larger air space with less total surface area.
Assume the concentration difference and diffusion distance are unchanged. Which statement predicts the effect?
Oxygen uptake increases because more molecules can cross at the same time.
Oxygen uptake decreases because fewer molecules can cross at the same time.
Oxygen uptake decreases because molecules must cross a thicker barrier.
Oxygen uptake increases because molecules must cross a thinner barrier.
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.