Equal samples of living seedling root tissue were placed in a concentrated sugar solution containing nitrate ions.
The nitrate ion concentration was 8.0 mmol per dm3 inside the root cells and 1.0 mmol per dm3 in the solution.
A chemical that stops respiration was added to one sample.
The results after 40 minutes are shown in the table.
| Treatment | Decrease in mass of root tissue in g | Nitrate ions taken up by root tissue in mg |
|---|---|---|
| Respiration not stopped | 0.48 | 0.30 |
| Respiration stopped | 0.46 | 0.01 |
Explain how the results show that the movement of water and nitrate ions across the root cell membranes involves different transport processes.
140 exam-style questions on AQA GCSE Biology 1.3 Transport in cells, covering 1.3.1 Diffusion, 1.3.2 Osmosis, and 1.3.3 Active transport. Each one has a worked solution and a mark scheme showing where the marks go.