Plant leaves are adapted for photosynthesis and gas exchange. Roots absorb water and mineral ions through root hair cells and are transported up the plant by the xylem.
The uptake of water can be measured using a potometer. Under normal circumstances, the rate of water uptake gives a measure of the rate of transpiration.
A simple potometer is a piece of capillary tubing to which a plant has been connected. The water uptake is measured by recording the time taken for a bubble in the tube to move a set distance.
To find the rate of water uptake of a plant.
Care must be taken when inserting the plant shoot into the rubber tubing attached to the capillary tube and with the scissors used to cut the plant shoot.
Time in minutes | Distance moved by bubble in mm |
---|---|
0 | 0 |
5 | 16 |
10 | 32 |
15 | 47 |
20 | 64 |
25 | 80 |
30 | 95 |
Plot a line graph of the data.