B8 transport in plants Flashcards
1
Q
function of xylem
A
- transport of water and mineral ions
- support
2
Q
function of phloem
A
transport of sucrose and amino acids
3
Q
function of root hair cell
A
- absorb water and mineral ions from soil
- increase SA of roots for increased absorption of nutrients
4
Q
A
5
Q
pathway taken by water through plants
A
- root hair cells
- root cortex cells
- xylem
- mesophyll cells
6
Q
what is transpiration
A
loss of water vapour from leaves
7
Q
describe transpiration in leaves
A
- water evaporates from surfaces of mesophyll cells
- into air spaces
- diffuses out of leaves through stomata as water vapour
8
Q
factors affecting transpiration rate
A
- temperature
- wind speed
- humidity
9
Q
how does increasing temperature affect transpiration rate
A
- increase evaporation
- higher rate
10
Q
how does increasing wind speed affect transpiration rate
A
- clears water vapour away from surface of leaf
- maintain conc gradient
- higher rate
11
Q
how does increasing humidity affect transpiration rate
A
- leaf surrounded by moist air
- conc gradient decreases
- lower rate
12
Q
what apparatus is used to demonstrate transpiration
A
potometer
13
Q
why does wilting occur
A
- rate of transpiration > rate of absorption thru rhc
- cells lose water, reduce turgor pressure, become flaccid
14
Q
describe translocation
A
- movement of sucrose and amino acids
- in phloem
- from sources to sinks
15
Q
what is a source in a plant
A
parts of plants that release sucrose or amino acids
