A scientist investigated the uptake of a dissolved ion, R, by insect cells grown in a nutrient solution.
The concentration of R was 0.28 mmol per dm3 in the nutrient solution and 1.40 mmol per dm3 inside the cells.
The scientist measured the uptake of R by identical samples of cells under two conditions. All other conditions were kept the same.
| Condition | Rate of uptake of R in μmol per gram per hour\mu\text{mol per gram per hour}μmol per gram per hour |
|---|---|
| Oxygen supplied | 46 |
| No oxygen supplied | 13 |
Calculate the percentage of the uptake rate in the oxygen-supplied cells that was oxygen-dependent.
Give your answer to 2 significant figures.
Explain why the results provide evidence that active transport contributed to the uptake of R.
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.