A non-poisonous grassland plant has white patches on its leaves. The pattern of the patches is similar to the pattern on the leaves of a poisonous plant in the same habitat. Leaf-eating beetles become unwell after eating the poisonous plant.
A scientist allowed some beetles to feed on the poisonous plant. Other beetles were not allowed to feed on the poisonous plant.
The scientist then gave each beetle a leaf from the non-poisonous plant. On some leaves, the white patches were covered with a green coating. The coating did not change the smell or taste of the leaves.
| Previous experience of poisonous plant | White patches | Mean area of leaf eaten in 24 hours in cm² |
|---|---|---|
| Fed on poisonous plant | Visible | 0.7 |
| Fed on poisonous plant | Covered | 3.1 |
| Not fed on poisonous plant | Visible | 2.9 |
| Not fed on poisonous plant | Covered | 3.0 |
Explain how the results support the idea that the white patches defend the non-poisonous plant.
Suggest how the disappearance of the poisonous plant from the habitat could affect the growth of the non-poisonous plant.
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.