Transpiration

Question 1

What is transpiration?

Answer 1

loss of water from stomata.

Question 2

Give the stages of transpiration.

Answer 2

1. stomata open during sunlight to access carbon dioxide, water inside the plant diffuses out.
2. There is now a higher concentration of water inside roots than in leaves, so more water is pulled up to leaves through xylem via osmosis to replace the water lost by transpiration.

Question 3

What factors affect the rate of transpiration?

Answer 3

1. Temperature
2. Light Intensity
3. Air Movement.

Question 4

How does temperature affect transpiration?

Answer 4

A high temperature increases the rate of transpiration because the water will evaporate faster

Question 5

How does light intensity affect transpiration?

Answer 5

High light intensity increases the rate of photosynthesis, which means more stomata open to absorb carbon dioxide, so more water evaporates and the rate of transpiration goes up.

Question 6

How does air movement affect transpiration?

Answer 6

Lots of air movement means more water is swept away, maintaining a low concentration of water outside the leaf, so water diffuses out of the leaf, increasing the rate of transpiration.

Question 7

How does a potometer allow us to measure the rate of transpiration?

Answer 7

1. As the plant transpires, water moves towards the plant.
2. Air bubble follows the water.
3. If the rate of transpiration is high, the air bubble will move quicker,

Question 8

Describe what happens when the stoma open.

Answer 8

1. Stoma open when the vacuole is enlarged (filled with water)

2l The stoma open during the day as the guard cells push them apart.

3. Carbon dioxide enters the plant
4. During this time, the guard cells are turgid.

Question 9

Describe what happens when the stomata are closed.

Answer 9

1. Stomata are closed when the vacuole shrinks and loses water during the night,
2. During this time the guard cells are flaccid.

Question 10

What are the stomata?

Answer 10

Small pores that allow gases to diffuses into or out of plant leaves.

Question 11

What controls the size of the stomata?

Answer 11

Guard cells