Substances can move across cell membranes by diffusion and by active transport.
Describe two differences between diffusion and active transport.
Cells lining the small intestine absorb glucose by active transport. These cells contain many mitochondria.
Explain why these cells contain many mitochondria.
41 exam-style questions on Edexcel GCSE Biology 1.4 Transport across cell membranes, covering 1.4.1 Transport into and out of cells and 1.4.2 Percentage gain and loss in osmosis. Each one has a worked solution and a mark scheme showing where the marks go.