A farmer grows a wheat crop in soil that contains very few nitrate ions. Which symptom is the wheat crop most likely to show?
A mosaic pattern of pale patches across the older leaves
Purple and black spots forming on the surface of the leaves
Yellow areas spreading between the green veins of the leaves
Stunted growth, with stems much shorter than normal stems
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.