A biogas generator is filled with animal waste and is then sealed so that air cannot enter. Which statement describes what happens inside the generator?
Carbon dioxide is produced because the microorganisms respire aerobically
Methane is produced because the microorganisms respire aerobically
Carbon dioxide is produced because the microorganisms respire anaerobically
Methane is produced because the microorganisms respire anaerobically
83 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.