A young apple tree has a mass of 0.6 kg. Twenty years later the tree has a mass of 380 kg. The mass of the soil the tree is growing in has hardly changed.
Explain where most of the extra mass of the tree has come from.
Suggest why the mass of the soil has hardly changed.
68 exam-style questions on AQA GCSE Biology 4.1 Photosynthesis, covering 4.1.1 Photosynthetic reaction, 4.1.2 Rate of photosynthesis, and 4.1.3 Uses of glucose from photosynthesis. Each one has a worked solution and a mark scheme showing where the marks go.