Which of the following statements correctly details a characteristic of an effective gas exchange surface and its significance?
Constant ventilation of the lungs maintains a steep concentration gradient.
A dense network of capillaries allows the concentration of gases to reach equilibrium.
Folding of the exchange surface reduces the surface area to volume ratio.
Squamous epithelial cells are highly layered to reduce the diffusion distance.
34 exam-style questions on OCR A A Level Biology Exchange surfaces. Each one has a worked solution and a mark scheme showing where the marks go.