3.1.3 c potometer

Question 1

how do you set up a potometer?

Answer 1

1) place all equipment underwater and squeeze all the air out of the tubing
2) assemble potometer underwater and cut the stem underwater
3) push plant stem into the tubing of the potometer
4) place capillary tube into beaker filled with water
5) take apparatus out of the water
6) blot any water on leaves
7) remove the capillary tube from the beaker
8) blot the end of the capillary tube, leaving an air bubble
9) place the capillary tube back into the beaker of water
10) measure the time taken for the bubble to move with a stopwatch

Question 2

why do you have to assemble the apparatus underwater?

Answer 2

so no air can enter because if air enters it could block the xylem and that would stop the continuous water column