gas exchange in plants Flashcards
1
Q
xerophyte
A
plants adapted to living in areas with little water
2
Q
mesophyll
A
where gas exchange of CO2 occurs for photosynthesis
3
Q
how is mesophyll adapted?
A
it is spongy meaning it has a large surface area
4
Q
stomata
A
- pores surrounded by 2 guard cells which control their movement
- can be opened or closed in order to limit water loss
5
Q
if a plant has little water what happens to the guard cells?
A
- cells become flacid
- causing the guard cells to close the stomata
6
Q
how is a thick waxy cuticle an adaptation for xerophytic plants?
A
- it is a waterproof barrier
- so reduces evaporation
7
Q
how is a curled leaf an adaptation for xerophytes?
A
- lower epidermis is shielded
- region of still, damp air is created
- meaning the water potential is very high
- so there is no water potential gradient in/outside the leaf
8
Q
how is having stomata in pits an adaptation for xerophytes?
A
- still, moist air is trapped against the leaf
- increasing humidity
- so there is no water potential gradient
9
Q
how is hairy leaves an adaptation for xerophytes?
A
- hairs trap still, moist air next to epidermis
- so water vapour builds up
- which decreases the water potential gradient
10
Q
how is having fewer stomata an adaptation for xerophytes?
A
less chances for water to diffuse out of the plant
