Farmers sometimes spray a dilute caffeine solution on crops to act as a natural deterrent against herbivorous pests like cabbage white caterpillars (Pieris brassicae).
Design an investigation to find out if spraying cabbage leaves with a caffeine solution affects the mass of leaf material consumed by caterpillars.
31 exam-style questions on Edexcel IGCSE Biology The organism in the environment. Each one has a worked solution and a mark scheme showing where the marks go.