A grower finds that tobacco mosaic disease spreads much faster between the tomato plants in a greenhouse when aphids are present. Which explanation of this observation is correct?
The aphids damage the roots, so more virus is absorbed from the soil
The aphids remove sugars, so the plants cannot build new cell walls
The aphids weaken the plants, so the virus reproduces more quickly
The aphids carry the virus on their mouthparts to healthy plants
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.