An investigator designed an experiment to study osmosis using cylinders of butternut squash.
The investigator placed 40 cm340\text{ cm}^340 cm3 of mannitol solution of different concentrations into six different beakers, labelled A to F. They then added one butternut squash cylinder of identical mass and surface area to each beaker. After 6 hours, the cylinders were removed and the volume of solution remaining in each beaker was measured.
The results are shown in the table below:
| Beaker | Concentration of mannitol solution (mol/dm3\text{mol/dm}^3mol/dm3) | Volume of solution at start (cm3\text{cm}^3cm3) | Volume of solution after 6 hours (cm3\text{cm}^3cm3) |
|---|---|---|---|
| A | 0.0 | 40 | 34 |
| B | 0.2 | 40 | 37 |
| C | 0.4 | 40 | 43 |
| D | 0.6 | 40 | 46 |
| E | 0.8 | 40 | 46 |
| F | 1.0 | 40 | 46 |
Define the term osmosis.
Name the independent variable and one controlled variable in this investigation.
Use the data to estimate the concentration of the cytoplasm in the butternut squash cells, explaining your reasoning.
Identify all the beakers in which the butternut squash cylinders lost water.
23 exam-style questions on Edexcel IGCSE Biology Movement of substances into and out of cells. Each one has a worked solution and a mark scheme showing where the marks go.