Tobacco mosaic disease produces a mosaic pattern of pale, discoloured patches on the leaves of a tomato plant. Which type of pathogen causes tobacco mosaic disease?
A fungus that grows on the surface of the leaf
A bacterium that lives in the soil around the root
A virus that reproduces inside the cells of the leaf
A protist that is carried into the plant by an insect
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.