Topic 2a - Tissues, organs and organ systems ( 8. transpiration and stomata)

Question 1

state the factors effecting the transpiration rate

Answer 1

light intensity
temperature
air flow
humidity

Question 2

how does light intensity effect transpiration rate

Answer 2

bright the light the greater the transpiration rate. Stomata begin to close as it gets darker. Photosynthesis cannot occur in the dark. when the stomata is closed very little water can escape.

Question 3

how does temperature effect transpiration rate

Answer 3

warmer it is the faster the transpiration rate. when its warm water particles have more energy to evaporate and diffuse out of the stomata.

Question 4

how does the air flow effect transpiration rate

Answer 4

the better the air flow around the leaf, the greater the transpiration rate.

Question 5

how does humidity effect transpiration rate

Answer 5

drier the air around the leaf the faster the transpiration happens.

Question 6

how can you estimate the rate of transpiration

Answer 6

by measuring the uptake of water by a plant. this is because you can assume that water uptake by the plant is directly related to the water loss by the leaves transpiration. record the distance moved by the bubble.

Question 7

what are guard cells

Answer 7

2 guard cells surround each stomata. they have a kidney shape which opens and closes the stomata in a leaf.

Question 8

what happens to the guard cell when the plant has a lot of water

Answer 8

guard cells fill with water and go plump and turgid. this makes the stomata open so gases can be exchanged for photosynthesis.

Question 9

what happens to guard cells when the plant is short of water

Answer 9

guard cells lose water and become flaccid making the stomata close. helps to stop too much water vapour from escaping.