A laboratory compares saline solutions before using one to suspend red blood cells for examination.
The table shows the mean volume of the cells before and after exposure to each solution.
| Concentration of saline solution in mol/dm3\text{mol/dm}^3mol/dm3 | Mean initial volume in fL\text{fL}fL | Mean final volume in fL\text{fL}fL |
|---|---|---|
| 0.10 | 90.0 | 96.0 |
| 0.18 | 90.0 | 84.0 |
Calculate the percentage change in mean cell volume for each saline concentration.
Assuming mean cell volume changes linearly between the two concentrations, estimate the saline concentration at which the mean final volume would equal the initial volume.
A separate sample of red blood cells is exposed to saline at 0.22 mol/dm3. Explain how the cells' volume will change.
194 exam-style questions on OCR GCSE Biology 2.1 Supplying the cell, covering 2.1.1 Transport across cell membranes, 2.1.2 Mitosis and the cell cycle, 2.1.3 Importance of cell differentiation, and 2.1.4 Stem cells. Each one has a worked solution and a mark scheme showing where the marks go.