Factors Effecting The Rate If Transpiration

Question 1

What factors effect the rate of transpiration

Answer 1

Temperature
Light intensity
Humidity
Wind intensity

Question 2

If each factor were increased what would happen?
Temp:
Humidity:
Air movement:
Light intensity:

Answer 2

Temp: increase molecular movement, more water-molecules evaporate from surfaces (RoD increased)

Humidity: decrease concentration of water-molecules outside lead: diffusion of water from lead increased

Air movement: more water vapour is lost from leaf surfaces as RoD increased due to high maintenance of concentration gradient

Light intensity: increases R o photosynthesis; stomata opens so water diffuses out of leaf

Question 3

How would i carry out an experiment measuring the rate if transpiration in a plant

Answer 3

1. Set up the potometer by filling it completely with water to remove any air and dry leaves.
2. Cut the leafy shoot underwater to prevent air from entering the xylem, then insert it into the potometer.
3. Seal all joints with Vaseline to make sure no water escapes.
4. Introduce a small air bubble into the capillary tube.
5. Start the stopwatch and measure the distance the bubble moves over a set time (e.g., every 5 minutes for 15 minutes).
6. Change environmental conditions (e.g., increase light or wind) to test how they affect the rate of transpiration.
7. Repeat the experiment for each condition and record the distance the bubble moves.

Question 4

Why do we add Vaseline to the shoot

Answer 4

To prevent leakage

Question 5

Why do leaves need to be dry at the begining

Answer 5

So it can be equilibrate - make it a fair test