A habitat management team removes dead reeds from a wetland. Equal masses of chopped reeds are placed in four rooms under different conditions.
| Room | Temperature | Reeds | Oxygen supply |
|---|---|---|---|
| A | Cold | Moist | High |
| B | Warm | Moist | High |
| C | Warm | Dry | High |
| D | Warm | Moist | Low |
Which room is most likely to make the reeds decay fastest by aerobic processes?
Room A, because cold conditions prevent decomposer enzymes from being denatured while oxygen remains available.
Room C, because dry material allows oxygen to reach decomposers while warmth keeps their enzymes active.
Room D, because a low oxygen supply reduces respiration so decomposers use less energy during decay.
Room B, because warmth increases decomposer enzyme activity and the high oxygen supply supports aerobic respiration.
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.