gas exchange in plants and animals Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

5 features of a specialised gas exchange surface

A
  • high surface area to volume ratio to increase rate of exchange
  • very thin, small diffusion pathway so faster rate of diffusion
  • selectively permeable to allow selected materials to cross
  • movement of the environment medium (eg air) to maintain a diffusion gradient
  • a transport system to ensure the movement of the internal medium (eg blood) to maintain diffusion gradient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

ficks law

A

surface area x concentration difference
——————————————————-
length of diffusion path

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

is diffusion more rapid in air or water

A

air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how is a leaf adapted for efficient gas exchange

A

large SA to volume ratio
very short diffusion pathway
air spaces in the spongy mesophyll layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how do guard cells open and close stomata

A

when water enters guard cells swell and become turgid
thin elastic wall stretches with turgor pressure
thicker inelastic cell wall (against opening) does not

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is a xerophyte

A

plants that are adapted to living in areas where their water losses due to transpiration may exceed their water uptake.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

cuticle

A

forms a waterproof barrier
the thicker the cuticle the less water can escape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

hairy leaves

A

traps still moist air next to leaf surface
reduces water potential gradient
less water lost by evaporation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

rolling leaves

A

protects lower epidermis from outside helps trap air within the leaf
region becomes saturated with water
water potential gradient disappears

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

stomata in pits/grooves

A

traps moist air next to the leaf,reducing water potential gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

reduced SA:vol ratio

A

thin needles
reduce SA
reduce water loss
(but need to have enough SA for sufficient photosynthesis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the internal system of tubes where gas exchange takes place in insects called

A

trachea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the smaller dead wand tubes of the trachea called

A

tracheoles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the open ends of the trachea called

A

spiracles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how is the diffusion gradient in the insect tracheal system maintained

A

O2 used up so concentration towards tracheole falls
creates a diffusion gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly