Two soil trays each contain the same mass of dead insect material and are supplied with air. One tray is kept at 20 °C and the other at 10 °C. Carbon dioxide concentrations in the air leaving each tray are measured at the start and after 7 days.
| Temperature of tray | Carbon dioxide concentration at start (%) | Carbon dioxide concentration after 7 days (%) |
|---|---|---|
| 20 °C | 0.04 | 0.28 |
| 10 °C | 0.04 | 0.13 |
Calculate the increase in carbon dioxide concentration in each tray and use the results to explain why the increases are different.
101 exam-style questions on Edexcel GCSE Biology 9.3 Material cycles and decomposition, covering 9.3.1 Cycling of materials through ecosystems, 9.3.2 The carbon cycle, 9.3.3 The water cycle, 9.3.4 The nitrogen cycle, 9.3.5 Indicator species and pollution, 9.3.6 Decomposition in preservation and composting, and 9.3.7 Rate changes in decay of biological material. Each one has a worked solution and a mark scheme showing where the marks go.