Jam is made by boiling fruit with a large mass of sugar. Jam with a high sugar concentration does not go mouldy, even after several months in an open jar.
Explain why mould does not grow on jam that has a high sugar concentration.
A manufacturer makes a reduced sugar jam. Suggest why this jam must be kept in a refrigerator once the jar has been opened.
58 exam-style questions on AQA GCSE Biology 1.3 Transport in cells, covering 1.3.1 Diffusion, 1.3.2 Osmosis, and 1.3.3 Active transport. Each one has a worked solution and a mark scheme showing where the marks go.