3.3 Passage of water through plant Flashcards Preview

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Flashcards in 3.3 Passage of water through plant Deck (40):
1

what percentage of water passing through a plant is used for photosynthesis?

1%

2

the 99% of water not used in photosynthesis evaporates from the leaves in which process?

transpiration

3

what is the highest water potential?

0 (pure water)

4

the more solute the ....... the water potential?

lower

5

the greater the number of water particles the ........ the water potential?

higher

6

what is water key in?

structure and metabolism of plants

7

turgor/hydrostatic pressure is a result of what?

osmosis

8

what does turgor/hydrostatic pressure create in plants?

hydrostatic skeleton

9

what does turgor drive in plants?

cell expansion

10

what does evaporation do to plants?

cools them down

11

mineral ions and products of photosynthesis are transported in what?

aqueous solutions

12

water is a raw material for what?

photosynthesis

13

does soil solution have a high or low water potential? why?

high it is mainly eater with small quantities of mineral ions

14

inside the root is there a high or low water potential?

low

15

why is there a low water potential in the root?

there are amino acids, mineral ions and sugars

16

water moves into the root hair cell down a what?

water potential gradient

17

how are root hairs an adaptation to help absorb water?

increase root surface area which increases speed of water uptake

18

how else are plant roots adapted to absorb water?

thin surface layer of cellulose wall and cell surface membrane (short diffusion distance)

19

what are the two routes which the water can move from the root hair cell into the xylem?

apoplastic pathway
symplastic pathway

20

what does the apoplastic pathway use?

the apoplast/outside

21

what does the symplastic pathway use?

the symplast/middle

22

water moves through the symplast by what process?

osmosis

23

(symplast) due to water diffusing in from soil the root hair cell has higher water potential than the next cell, so what does water do?

moves from root hair to next cell along by osmosis

24

(symplast) water moves from cell to cell until what is reached?

the xylem

25

(symplast) when the xylem is reached water moves through which p?

plasmodesma

26

what is the plasmodesma?

gaps between the cell

27

(symplast) as water leaves the root hair what happens to the water potential of the cytoplasm? what does this maintain?

it decreases
maintaining steep water potential gradient

28

in the apoplast pathway what does water fill?

spaces between network of fibres in cellulose cell wall

29

(apoplast) as water moves into the xylem, what happens to more water molecules?

pulled through apoplast due to cohesive forces between molecules

30

(apoplast) what do the cohesive forces between water molecules create?

tension

31

(apoplast) what does the tension of the water result in?

continuous flow of water through the cellulose wall with little or no resistance

32

in the apoplast pathway the water reaches the endodermis and the casparian strip, what is this?

waterproof band in the endodermal cells preventing the water from passing

33

what happens to the water reaching the casparian strip by the apoplast?

forced into protoplast (living part) joining water from symplast

34

what is the mechanism by which the water gets into the xylem from the symplast and apoplast?

active transport of salts into the xylem

35

when endodermal cells actively transport salts into the xylem what does it create and what does it result in?

lower water potential so water moves into xylem by osmosis
creating force moving water up the plant - root pressure

36

what happens to root pressure when temperature increases?

pressure increases

37

temperature increase will increase the rate of production of what?

ATP

38

why does increased temperature increase ATP production?

root pressure requires energy
ATP is produced by enzymes which work faster and more efficiently at high temperatures

39

how do metabolic inhibitors affect root pressure?

prevent energy release by respiration, no energy for root pressure

40

give an example of a metabolic inhibitor:

cyanide

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