transpiration

Question 1

is the evaporation of water from the aerial parts of plants

Answer 1

transpiration

Question 2

of all the water plant absorbs, over ______ is transpired to the air as water vapor

Answer 2

95-99%

Question 3

from where water is transpired?

Answer 3

1) lenticel (lenticular transpiration) - 0.1%
2) cutin (cuticular transpiration) - 3-10%
3) stomata (stomatal transpiration) - ~90%

Question 4

prevents water loss

Answer 4

cuticle

Question 5

site of photosynthesis

Answer 5

mesophyll

Question 6

openings allow gases and wate to move in and out of leaf

Answer 6

stomata

Question 7

open and close the stomata

Answer 7

guard cells

Question 8

what goes out of stomata?

Answer 8

o2 and h2o

Question 9

what goes in to stomata?

Answer 9

co2, h2o (sometimes ?)

Question 10

what process involves using CO2 and H2O releasing O2 as a waste product?

Answer 10

photosynthesis

Question 11

what is the plant using this process (photosynthesis) to make?

Answer 11

glucose (carbs)

Question 12

if the plant needs water for photosynthesis, why is water coming out of the stoma?

Answer 12

the stomata naturally allow water to evaporate out

Question 13

why would the plant close stomata with guard cells?

Answer 13

to prevent excess water loss through transpiration or to conserve water

Question 14

what is the point of having stomata?

Answer 14

allows gas exchange for photosynthesis and transpiration to occur

Question 15

what is the function of cellulose microfibril?

Answer 15

increase cell strength

Question 16

function of accessory/subsidiary cells?

Answer 16

surround and support the guard cells, act as a buffer b/w epidermal and guard cells

Question 17

how do the guard cells react to the availability of water when dry and lots of water?

Answer 17

when dry - close
lost of h2o - open

Question 18

when stomata is open, what happens?

Answer 18

gas exchange and transpiration

Question 19

kidney-shaped guard cells are for?

Answer 19

dicots

Question 20

dumbbell-shaped guard cells are for?

Answer 20

monocots

Question 21

dorsal or outer side of the guard cell has a ___ cell wall

Answer 21

thin cell wall

Question 22

ventral or inner side of the guard cell has a ___ cell wall

Answer 22

thick cell wall

Question 23

they contain ____ and can perform ____ reactions (not ____ for the lack of key _____)

Answer 23

guard cells; chloroplastl light; calvin cycle; enzymes

Question 24

are structurally isolated from _____ cells for the lack of ______ (water and ions transmit only through _____ pathway, thus helping to build up ______)

Answer 24

guard cells; epidermal cells; plasmodesmata; cellular; water gradient

Question 25

little _____, little amount of water absorption or loss controls ______

Answer 25

volume; stomatal aperture

Question 26

low aperture of guard cells =

Answer 26

small opening

Question 27

mechanism of stomata opening?

Answer 27

K+ absorption theory

Question 28

when stomata is opening (K+ AT) what happens?

Answer 28

K+ rises to 0.5 M, anions rise to 0.2-0.5 M, osmotic potential drops 2 MPa

Question 29

what are the factors influencing the stomatal aperturte?

Answer 29

light, temperature, plant hormones, co2, water content

Question 29

stomata of most plants open in the ____ and close at _____, while ___ plants are just the opposite

Answer 29

day; night; CAM

Question 30

stomata opening is sensitive to ____ and ____ light, and _____ light is more effective, it stimulates opening by a ____ receptor: _______

Answer 30

red and blue lights; blue light; blue-light; zeaxanthin

Question 31

stomatal apertures ____ with Temperature, within ________ (the _________

Answer 31

increase, 20-30°C (optimal)

Question 32

______ CO2 concentration promotes stomatal opening

Answer 32

low

Question 33

___ CO2 concentration inhibits stomatal opening through its _____ of the guard cell thus inhibits plasma membrane ________

Answer 33

high; acidication; hyperpolarization

Question 34

stomata _____ when the leaf contains enough water. When there is a water shortage, they _____

Answer 34

opens; close

Question 35

promotes opening of stomata

Answer 35

cytokinins

Question 36

inhibits opening of stomata or it closes the stomata

Answer 36

abscisic acid

Question 37

what are the factors that influence transpiration rate?

Answer 37

light, temperature, humidity, wind, soil water

Question 38

transpiration from the leaf depends on two major factors:

Answer 38

1) difference in water vapor gradient 2) diffusional resistance

Question 39

this is the driving force of transpiration

Answer 39

vapor pressure gradient

Question 40

this is the difference in vapor pressure between the internal spaces in the leaf and the atmosphere around the leaf

Answer 40

vapor pressure gradient

Question 41

diffusional resistance is comprised of what?

Answer 41

stomatal resistance and boundary layer resistance

Question 42

this resists transpiration

Answer 42

air boundary layer

Question 43

formula of transpiration rate

Answer 43

transpiration rate = driving force / resistance

Question 44

plants transpire more rapidly in the ____ than in the ____. This is largely because light stimulates the ______ of the stomata

Answer 44

light; dark; opening

Question 45

light also speeds up transpiration by _____ the leaf

Answer 45

warming

Question 46

plants transpire more rapidly at _____ temperatures because water evaporates more rapidly as the temperature rises

Answer 46

higher

Question 47

when the surrounding air is ____ or ___ humid, diffusion of water out of the leaf goes on more rapidly

Answer 47

dry, low humid

Question 48

when a _______ is present, the humid air is carried away and replaced by ____ air

Answer 48

breeze; drier

Question 49

a plant cannot continue to transpire rapidly if its _____ is not made up by replacement from the soil

Answer 49

water loss

Question 50

when absorption of water by the roots fails to keep up with the rate of transpiration, loss of _____ occurs, and the stomata _____. This immediately ______ the rate of transpiration

Answer 50

turgor; close; reduces

Question 51

if the loss of turgor extends to the rest of the leaf and stem, the plant _____

Answer 51

wilts