A scientist grew two groups of young radish plants for 5 days. The plants were kept under the same conditions. The mineral solutions supplied to the groups were identical, except that the solution supplied to group 2 contained no nitrate ions.
The table shows the mean increase in the mass of four substances in each plant.
| Substance | Increase with nitrate ions in mg | Increase without nitrate ions in mg |
|---|---|---|
| Starch | 24.8 | 23.9 |
| Cellulose | 31.2 | 30.4 |
| Lipids | 7.6 | 7.4 |
| Proteins | 18.5 | 3.1 |
Use the data and your knowledge of metabolism to explain how removing nitrate ions affected the substances made by the plants.
92 exam-style questions on AQA GCSE Biology 4.2 Respiration, covering 4.2.1 Aerobic and anaerobic respiration, 4.2.2 Response to exercise, and 4.2.3 Metabolism. Each one has a worked solution and a mark scheme showing where the marks go.