Topic 3 potometer

Question 1

How do you use a potometer?

Answer 1

1. Assemble apparatus under water
2. Remove any visible air bubbles
3. Seal all joints with Vaseline
4. Dry leaves on removal from water
5. Lift capillary tube out of water to introduce an air bubble
6. Wait for air bubble to reach 0 on scale
7. Record distance air bubble travels in certain time

Question 2

What does a potometer measure?

Answer 2

Water used up during photosynthesis (will be more than water lost during transpiration, as water is used in other functions in the plant)

Question 3

Why does it need to set up underwater?

Answer 3

Sealed with Vaseline as well

So air can’t get in

Question 4

What is the purpose of the reservoir?

Answer 4

Let more water in and set bubble back to its starting position