module 3-transport in plants

Question 1

transport in plants needed for

Answer 1

metabolic demands
size
sav

Question 2

metabolic demands

Answer 2

many parts of plants need o2 and glucose
need waste products to be removed
hormones needed for transpiration.

Question 3

size

Answer 3

need effective transport to move substances up and down.

Question 4

SAV

Answer 4

leaves adapted to have large SAV exchange
cannot rely on diffusion to supply thier cells

Question 4

xylem

Answer 4

largely non living tissue
made of several types of cell, and most are dead when functioning.
long hollow structures made by several colums fusing.
has two tissue
long cell with secondary walls
lignin, rto support
form rings, which is boarded pits, so water can leave xylem.

Question 4

what are the tissues in xylem

Answer 4

xylem parenchyma, which packs around the xylem vessel.
stores food.
contains tannin

Question 4

functions of xylem

Answer 4

transport of h20 and mineral ions
flow of materials in xylem is up from roots to shoots and leaves.

Question 5

what is tannin

Answer 5

bitter chemicals to avoid herbivores.

Question 6

pholem

Answer 6

living tissue transporting food
supply cells with sugars and aamino acids. needed for respiration.
flow can go up or down .
not lignified.
walls form sieve plates, to allow content to flow
large pores, allow nucleus and organelles to break down
becomes tube filled with sap.
a mature pholem has no nucleus

Question 7

what is main transport vessels for pholem

Answer 7

sieve tube elements, made from cells joined end to end, and are long and hollow

Question 8

companion cells

Answer 8

very active cells, which have life support system so lost most normal functiobs

Question 9

companion cells are closely linked to…

Answer 9

sieve test tubes.
these have many plasmodesmata, (microscopic channels linking cytoplasm)
maintains nucleus and all their organelles.

Question 10

hydrostatic shelton

Answer 10

hydrostatic pressure resulting in plant cell, to support stems and leaves. divides cell expansion, enabling plant to go through tarmac.
loss of water is by evaporation.
mineral ions/photosynthesis transport.

Question 11

root hair cells

Answer 11

exchange where water taken in.
long thin extension.
microscopic size, so pentrates easily.

Question 12

root hair cells hair

Answer 12

thin surface layer, so diffusion and osmosis can occur.

Question 13

soil water

Answer 13

low concentration of dissolved material, so has high water potential.

Question 14

cytoplasm

Answer 14

many solvents, and lower water potential

Question 15

movement of waters

Answer 15

symplast or anoplast

Question 16

symplast pathway

Answer 16

water moves along symplast by osmosis.
symplast=continuous cytoplasm of living plant cells connected through plasmodesmata.
root hair cells, have higher water potential then next cell, so diffuses from coil to next cell, until reaches xylem.
as water leaves the root hair cells by osmosi, water potential decreases, so water completely moves from the soil.

Question 17

anoplast pathway.

Answer 17

movement of water through cell wall and intercelluar spaces,
water fills spaces, between loose network.
water moves into xylem, more water pulled through due to choesvie forces of molecules.
pull from water moving to xylem and up plant, and creating tension, leading to flow of H2O.

Question 18

movement of water from xylem

Answer 18

water moves across root in apoplast and symplast, until reaches endodermis, where layer of cell surrounding vasuclar tissue
endothermisis is noticable due to the casparian strip.
water in apoplast go no further, so goes to cytoplasm, and joined in symplast, as goes through permable membrane so no toxic solutes go.

Question 19

casaparian strip

Answer 19

waxy material forming a waterproof layer.

Question 20

vascular tissue

Answer 20

xylem and pholem

Question 21

when enters vascular bund;e

Answer 21

water returns to apoplast pathway, so can enter xylem, so can move up.
active pumping of minerals to xylem, so water is moved by osmosis. THIS is root presusre

Question 22

root pressure

Answer 22

independent of any effects of transpiration, and gives water a push up.

Question 23

roles of active transport evidence

Answer 23

root pressure increases with temp increases.
levels of o2 fall, if root pressure falls.

Question 24

transpiration

Answer 24

have to ensure gagses move in and out for photosynthsis.
co2 moves from air to leave
o2 moves out through pores=stomata, opened and closed by guard cells.

Question 25

how are plants waterproof

Answer 25

surfaces covered with waxy cuctile, prevents cells losing water.

Question 26

stomata opens?

Answer 26

exchange of co2 and o2 between air and leaf.
water vapour moves out and is lost. this is known as transpiration.

Question 27

stomata opens/closes for

Answer 27

control water lost.
day opens-takes in co2
nigh closes-no need of sunlight

Question 28

transpiration steam

Answer 28

moves by osmosis across membranes
diffusion in apoplast from xylem through cells.evaporates from permeable wall to airspaces.
water vapour move to air through stomata along diffusion gradient.
mocves water up from roots of plants to highest leaves.

Question 29

transpiration steam-xylem

Answer 29

h2o evaporates of mesophll moving out of stomata by diffusion.
loss of water=lower water potential so move to cell by osmosis.
repeated across leafd to xylem, move by osmosis to cells.
ahension and cohesion

Question 30

ahension

Answer 30

water molecules form h2 bonds with carbohydrates.

Question 31

cohesion

Answer 31

water molecules form h2 bonds with each other

Question 32

combination of ahesion and cohesion

Answer 32

exhibits capilary action, so water moves up against gravity, in a continous stream, THIS IS TRANSPIRATION PULL.

Question 33

evidence of cohesion-tension theory

Answer 33

changing in diameters-tree shrinker when tension is highest.
xylem vessel broken, and air is pulled up, so plant dosent move

Question 34

stomata

Answer 34

turgor driven process
environmental favourable, guard cells pump solutes by active transport-MORE TURGOR.
cellulose hoops prevent cell swelling, move lengthway.
guard cells less flexible, so leads to cell becoming bean shaped.
less water-hormonal signals, so closes pores.

Question 35

turgor driven process

Answer 35

turgor is low-closes pore.

Question 36

factors affecting transpiration

Answer 36

temperature
air movement
soil water availability

Question 37

temperature

Answer 37

increases, more kinetic energy of water, so more evaporation. also more water vapour, so decreases humidity, both increasing transpiration.

Question 38

air movement

Answer 38

each leaf has layer of still air, which has hairs decreasing movement, so water vapour accumulates here, so higher water vapour potential, so higher gradient, and more rate of transpiration.

Question 39

translocation

Answer 39

leaves of a plant produce large amount of glucose=needed for respiration by cells.
this is converted to sucrose, and converted back.
active process-energy neede, substances moved up or down

Question 40

plants transport organic..

Answer 40

in phloem from sources to sink.

Question 41

sources

Answer 41

green leaves/green stems.
storage organs unloading stores.
food stores in seeds.

Question 42

sinks

Answer 42

roots growing/absorbing minearl ions.
meristems actively dividing
laying down food stores.

Question 43

pholem loading

Answer 43

Many plants, soluble products moved to pholem, from sources in active transport.
MAINLY surcose, as not used in metabolism.
Can be active and passive

Question 44

ACTIVE pholem loading

Answer 44

apoplast
surcose travels through cell wall/intercell spaces, to companion cells, by diffusion.
COMPANION CELLS-surcose moved to cytoplasm across membrane.
H+ pumped out of companion cells into tissue USING ATP, and returns to companion cells down concentration gradient via proteins.
SURCOSE is cotransported, more concentration in companion cells and in sieve elements.

Question 45

companion cells

Answer 45

many infoldings in cell membrane,MEANS higher surface area, and many mitochondria.
due to buildup of sucrose, water move by osmosis. higher turgor pressure, so water moves to sieve elements, reduces pressure in cells, so moves up/down by mass flow.

Question 46

solute accumlating-source

Answer 46

pholem leads to increase in turgour pressure, so sap goes to sink lower pressure. PRESSURE difference, leads to transport of sources.

Question 47

pholem unloading

Answer 47

sucrose unloaded from phloem.
can also be converted to another molecule. this maintains concentration. gradient between pholem and cells.

Question 48

loss of solutes from pholem

Answer 48

rises in water potential, so mvoes into surrounding cells by osmosis.
some water drawn to transpiration system.

Question 49

evidence of translocation

Answer 49

mitochondria poisioned-no translocation.
flow of sugars faster by diffusion alone.

Question 50

xerophytes.

Answer 50

plants have adaptations to conserve water.
including:
waxy cucticle, reduces transpiration
hot conditions, water evaporates rapidly.

Question 51

ways of conservation

Answer 51

thick waxy cucticle
sunken stomata-less air movement
less stomata
less leaves
hairy leaves
curled leaves
succleents
leaf loss
long roots

Question 52

hydrophytea

Answer 52

need adapations to lose water.

Question 53

ways of losing water

Answer 53

no waxy cuctile
many open stomata
no strucrure
wide flat, capture lots of light
small roots
stem root. large surface.

Question 54

endoermis

Answer 54

layer of cells covering xylem and pholem