A grower has three fields of tomato plants. Each field produces a much smaller mass of tomatoes than the grower expected. In field 1 the plants are infected with tobacco mosaic virus. In field 2 the plants are covered with aphids. In field 3 the soil contains very few magnesium ions.
Explain how the problem in each of the three fields reduces the mass of tomatoes produced.
58 exam-style questions on AQA GCSE Biology 3.3 Plant disease, covering 3.3.1 Detection and identification of plant diseases and 3.3.2 Plant defence responses. Each one has a worked solution and a mark scheme showing where the marks go.