plant transport

Question 1

transpiration

Answer 1

loss of water vapour form the stomata due to evaporation

Question 2

where does transpiration usually occur

Answer 2

leaves and stem

Question 3

factors that increases rate of transpiration [2]

Answer 3

1. increased temp
2. decreased humidity

Question 4

how does water affect transpiration

Answer 4

cohesive- hydrogen bond forms with each other
adhesive- water column is continuous

Question 5

adaptations of xylem [5]

Answer 5

1. hollow + made from dead cells
   - no need for osmosis
   - less obstruction
2. absent end walls
   - continuous flow of water
3. lignin
   - prevent xylem from collapsing
4. pits for water to enter and exit
5. narrow
   - capillary action

Question 6

diagram of stem

Answer 6

xylem inside
phloem outside

Question 7

diagram of root

Answer 7

xylem- star
phloem- circles

Question 8

function of xylem

Answer 8

transports water from the roots up the stem and leaves

Question 9

function of phloem

Answer 9

transport sucrose from the leaves to the roots

Question 10

function of cortex

Answer 10

unspecialised cells that bulk out the root to strengthen it and increase surface area

Question 11

function of endodermis

Answer 11

inner skin of cells that water must pass through to reach the xylem

Question 12

epidermis

Answer 12

absorbs water and mineral ions from the soil often using long narrow root hairs

Question 13

what does the companion cells use

Answer 13

co-transporter protein to transport sucrose and h+ ions form the source

Question 14

flow of sugars in phloem [4]

Answer 14

1. leaf cells produce sugars by photosynthesis
2. sugar transported form cell to cell in leaf
3. solutes actively transported into phloem
4. water diffuses into phloem

Question 15

phloem loading

Answer 15

source making sucrose bc photosynthesis

Question 16

how is proton concentration gradient maintianed

Answer 16

companion cell using atp to transport h+ to the source cell

Question 17

root pressure

Answer 17

positive pressure potential generated in xylem by active transport of mineral ions from roots to xylem

Question 18

movement of ions into the xylem

Answer 18

higher solute concentration in the xylem than in surrounding soil

Question 19

pressure

Answer 19

drives water and dissolved minerals up the plant’s stem

Question 20

pressure at leaves

Answer 20

negative hydrostatic pressure

Question 21

plasmodesmata

Answer 21

channels through the cell walls of plant cells that connect neighbouring cells

Question 22

apoplast pathway

Answer 22

pass thru the cell wall
- fast

Question 23

symplast pathway

Answer 23

goes thru cell (cytoplasm and vacuoles) to travel between cells
- slow

Question 24

how does water enter cytoplasm + result

Answer 24

osmosis by capillary action
- increased hydrostatic pressure

Question 25

how do mineral ions enter the root hair cells

Answer 25

active transport

Question 26

what happens when water leaves apoplast

Answer 26

enters endothermis
from synoplast

Question 27

why does water go up the xylem

Answer 27

difference in hydrostatic pressure potential

Question 28

concentration of sucrose, water and turgor pressure at the source

Answer 28

s- high
w- low
t- high

Question 29

concentration of sucrose, water and turgor pressure at the sink

Answer 29

s- low
w- high
t- low

Question 30

how does cohesion help water travel up the stem

Answer 30

dragged up using shoot tension

Question 31

why is water vapour lost

Answer 31

diffusion thru large amount of stomata

Question 32

function of sieve tube element

Answer 32

active translocation

Question 33

function of companion cell

Answer 33

take sucrose from the leaf
- facilitated diffusion + active transport

Question 34

lateral sieve area

Answer 34

plasmodesmata