Aphids are found on the stems of a crop plant. Why is this important when a disease is being detected?
The aphids feed on pathogens, so the crop recovers without treatment
The aphids show that the soil around the crop is deficient in nitrate
The aphids only settle on plants already infected by a plant pathogen
The aphids are a sign of damage and can carry pathogens to new 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.