CAIE A-Level Biology 9.1.7 Gas Exchange in the Alveoli
Practise explaining oxygen and carbon dioxide diffusion between alveolar air and blood using gradients and exchange-surface adaptations.
- Syllabus
- 2028–2030
- Course
- Biology 9700
- Level
- AS
Exam points
- state the direction of oxygen and carbon dioxide diffusion from their partial-pressure gradients
- link a large area and thin alveolar-capillary barrier to a short, rapid diffusion pathway
- explain how ventilation and blood flow maintain steep concentration gradients at the surface
