In a group of 40 courgette plants, malformed leaves and small growths appear. Samples from six affected plants are tested using a monoclonal antibody testing kit designed to detect bacterial pathogen P. All six samples give a negative result.
| Day after signs were first observed | Number of plants showing signs |
|---|---|
| 0 | 3 |
| 4 | 8 |
| 8 | 18 |
| 12 | 31 |
A student concludes that the signs are caused by a mineral deficiency and not by a pathogen.
Evaluate the student's conclusion. In your answer, suggest one method that could identify the exact cause.
133 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.