A submerged aquatic plant grows in a stream. Its broad leaves are one cell thick. The stream water contains a higher concentration of carbon dioxide than the leaf cells and flows continuously over both surfaces of each leaf. The leaf cells are photosynthesising.
Explain how the structure of the leaves and the movement of the stream water increase the rate at which carbon dioxide enters the leaf cells.
102 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.