A scientist investigates transpiration from the same group of plants in a greenhouse compartment.
The ventilation fan is operated at two different speeds. The temperature and light intensity remain constant.
| Measurement | Value |
|---|---|
| Water vapour added by the plants at low fan speed | 3.0 g per minute |
| Water vapour concentration of air leaving at low fan speed | 9.5 g/m³ |
| Water vapour concentration of air entering at high fan speed | 8.0 g/m³ |
| Water vapour concentration of air leaving at high fan speed | 8.6 g/m³ |
| Volume of air passing through at high fan speed | 10 m³ per minute |
Calculate the mass of water vapour added to the air by the plants each minute at high fan speed.
Using the data and your answer to (a), explain the effect of increasing the fan speed on the rate of transpiration.
114 exam-style questions on OCR GCSE Biology 2.2 The challenges of size, covering 2.2.1 Exchange surfaces and surface area : volume ratio, 2.2.2 Substances transported in organisms, 2.2.3 The human circulatory system, 2.2.4 The heart and blood vessels, 2.2.5 Red blood cells and plasma, 2.2.6 Uptake of water and mineral ions by plants, 2.2.7 Transpiration and translocation, 2.2.8 Xylem and phloem, 2.2.9 Environmental factors and water uptake, and 2.2.10 Using a potometer. Each one has a worked solution and a mark scheme showing where the marks go.