A company sells a testing kit for a plant virus. The company claims that its kit detects the virus in 99% of infected plants. A grower tests the kit on 10 plants from one greenhouse. All 10 plants show signs of disease. The kit gives a positive result for 6 of the 10 plants, so the grower concludes that the company's claim is false.
Give two reasons why the grower's conclusion is not valid.
Describe how the grower could improve this investigation.
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.