Trees have layers of dead cells around their stems. These layers are called bark.
Explain how layers of dead cells around a stem defend a tree against microorganisms.
Rose black spot is caused by a fungus that infects the leaves of a rose plant. In autumn the rose plant loses all of its leaves.
Explain how losing its leaves reduces the amount of rose black spot on the plant the following year.
A gardener leaves the fallen leaves on the ground under the rose plant. Suggest why the plant may still become infected the following year.
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.