A researcher placed four identical leafy shoots in separate controlled-environment cabinets. Each shoot was connected to a potometer. Light intensity and air movement were kept the same.
The table shows the mean movement of the air bubble in each potometer.
| Cabinet | Air temperature in °C | Humidity in % | Time in minutes | Mean distance moved by the air bubble in mm |
|---|---|---|---|---|
| A | 20 | 70 | 12 | 18 |
| B | 30 | 70 | 10 | 40 |
| C | 20 | 40 | 12 | 30 |
| D | 30 | 40 | 10 | 60 |
Calculate the difference between the mean rates of water uptake in cabinets A and D.
Give your answer in mm per minute.
Describe and explain how temperature and humidity affected the mean rate of water uptake by the shoots.
The researcher concluded that temperature had a greater effect on the mean rate of water uptake than humidity.
Evaluate this conclusion.
74 exam-style questions on AQA GCSE Biology 2.3 Plant tissues, organs and systems, covering 2.3.1 Plant tissues and 2.3.2 Plant organ system. Each one has a worked solution and a mark scheme showing where the marks go.