gas exchange in plants

Question 1

where in the plant does gas exchange occur?

Answer 1

stomata

Question 2

explain how gases exchange at the stomata?

Answer 2

• oxygen diffuses OUT of stomata
• carbon dioxide diffuses IN through stomata

Question 3

how do stomata reduce water loss?

hint: at night

Answer 3

• stomata close at night
• when photosynthesis wont occur because there is no light
• to reduce water loss by evapouration

Question 4

how is a leaf adapted for gas exchange?

Answer 4

concentration gradient:
- rate of photosynthesis establishes concentration gradient

diffusion distance:
- leaves are thin
- short diffusion distance between stomato and palisade mesophyll

surface area:
- large surface area of spongy mesophyll for rapid diffusion
- increase surface area:volume ratio

Question 5

describe the adapations of xerophyte plants for water loss?

Answer 5

• curled leaves –> to trap moisture to increase local humidity
• hairs –> to trap moisture to increase local humidity
• sunken stomata –> to trap mositure to increase local humidity
• thicker cuticle –? reduce evapouration
• longer root network to reach more water

Question 6

what are xerophyte plants?

Answer 6

plants adapted to live in enviroments with limited water