A pond contains the food chain: algae → water flea → stickleback → heron. Which organism is the secondary consumer?
The algae, which are eaten by the water fleas
The stickleback, which is eaten by the heron
The water flea, which is eaten by the stickleback
The heron, which is not eaten by any organism
40 exam-style questions on AQA GCSE Biology 7.2 Organisation of an ecosystem, covering 7.2.1 Levels of organisation, 7.2.2 How materials are cycled, 7.2.3 Decomposition, and 7.2.4 Impact of environmental change (HT only). Each one has a worked solution and a mark scheme showing where the marks go.