Bubble potometer

Question 1

Method

Answer 1

• Set up apparatus while under water
• Seal tubing with Vaseline so there’s no air leaks
• Support plant and apparatus with retort stand
• Measure distance the bubble moves at 20 degrees in a set period of time
• Repeat at different temperature
• Reset bubble using syringe/reservoir
• Calculate rate of transpiration D/T

Question 2

Why does the potometer measure water uptake accurately but not transpiration?

Answer 2

Some of the water taken up is used in other processed (photosynthesis, etc.)