Researchers placed dead moss on soil containing decomposer microorganisms. Wheat plants were growing in the same sealed, transparent chamber.
Lamps kept the wheat plants in the light. An air pump bubbled air through the soil. Researchers could identify carbon atoms that had come from the dead moss.
| Time after adding dead moss in days | Mass of carbon from the dead moss in carbon dioxide in the chamber air in mg | Mass of carbon from the dead moss in glucose in the wheat leaves in mg |
|---|---|---|
| 0 | 0 | 0 |
| 2 | 16 | 0 |
| 4 | 30 | 5 |
| 6 | 25 | 12 |
| 8 | 18 | 19 |
Use the data to explain how carbon from the dead moss became part of glucose in the wheat leaves.
The air pump was switched off on day 8.
Predict how this would affect the mass of carbon from the dead moss found in glucose in the wheat leaves by day 12, compared with leaving the pump switched on.
Explain your answer.
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.