Five cylinders are cut from the same swede for each of three sucrose solutions. The percentage change in mass of each cylinder is measured.
| Sucrose concentration (mol dm−3\text{mol dm}^{-3}mol dm−3) | Length of each cylinder (mm\text{mm}mm) |
|---|---|
| 0.20 | 20 |
| 0.40 | 30 |
| 0.60 | 40 |
All the cylinders have the same diameter. The volume of solution, temperature, time in the solution and method of blotting are kept the same. A mean percentage change in mass is calculated for each concentration.
Evaluate whether this method can give a valid comparison of the effect of sucrose concentration on the mass of the swede tissue.
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.