A leaf is photosynthesising in daylight. Carbon dioxide from the air enters the photosynthesising cells of the leaf.
A fan moves air continuously over the leaf. The fan is then switched off. Light intensity, temperature and all other conditions remain unchanged.
Explain why switching off the fan causes the rate of carbon dioxide uptake by the leaf to decrease.
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.