A gardener cuts branches off an apple tree in winter. This leaves an open wound on the trunk where the bark has been removed. The gardener paints the wound with a sealant.
Explain why removing an area of bark increases the risk of the tree becoming infected.
Suggest how painting the wound with a sealant reduces the risk of infection.
A different gardener does not use a sealant. She cuts the branches so that only a very small wound is left. Suggest why this also reduces the risk of infection.
The gardener cuts the branches in winter rather than in summer. Suggest one reason why the risk of a fungal infection is lower in winter.
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.