transport

Question 1

how are xylem and phloem different to animal vessels

Answer 1

there is no pump and gasses are not carried by these tussues

Question 2

what tissues support vascular bundle

Answer 2

collenchyma and sclerenchma

Question 3

were is xylem found in the young root

Answer 3

the central core of xylem in the shape of an x

Question 4

were is the phloem found in the young root?

Answer 4

in between the arms of the x shaped xylem tissue.

Question 5

were is the endodermis located in the young root?

Answer 5

around the vascular bundle

Question 6

what is the role of the endodermis bundle?

Answer 6

getting water into the xylem vessels

Question 7

what is inside the endodermis?

Answer 7

a layer of meristem cells called the pericycle

Question 8

what is the difference between the position of the vessels in non woody and woody stems?

Answer 8

in woody plants the bundles are separate and discrete but in woody plants this is the same for young stems however they become continuous rings

Question 9

what is in between the xylem and phloem in the stem?

Answer 9

a layer of cambium (meristem) cells

Question 10

xylem and phloem in the leaf

Answer 10

vascular bundle forms midrib were xylem is on top of phlem

Question 11

structure of xylem

Answer 11

fibres help support the plant

living parenchyma cells act as packing tissue support vessels

Question 12

lignin effect on xylem

Answer 12

makes it waterproof
hollows walls
strengthen walls
open
rings allow flexibility

Question 13

boarders pits

Answer 13

allow water to pass between vessels and pass onto living cell parts

Question 14

why is the flow of water not impeded by the xylem

Answer 14

no cross walls
no cell contents
lignin thickening

Question 15

structure of phloem

Answer 15

made up of sieve tube elements and companion cells

Question 16

features of sieve tubes

Answer 16

no nucleus
little cytoplasm
perforated crosswalls (sieve plates)
thin walls

Question 17

companion cell features

Answer 17

large nucleus
dense cytoplasm
numerous mitochondrea

Question 18

what are the plasmodesmata

Answer 18

cell junctions were the cytoplasm of one cell is connected to that of another through cell wall gaps

Question 19

apoplast pathway

Answer 19

water passes through spaces in the cell walls so moves by mass flow

Question 20

symplast pathway

Answer 20

water enters cell cytoplasm through plasma membrane and passes through plasmodesmata

Question 21

vacuolar pathway

Answer 21

same as symplast pathway however it can pass through the vacuoles

Question 22

what is the term for when the membrane loses contact with the cell wall

Answer 22

plasmolysis

Question 23

were does water evaporate from?

Answer 23

the spongey mesophyl

Question 24

importance of transpiration

Answer 24

useful for mineral ions
maintains cell turgidity
supplies water for growth
cools plants down

Question 25

what is adhesion

Answer 25

attraction between water and xylem walls

Question 26

endodermis?

Answer 26

layer of cells surrounding the medulla and xylem contains starch granules

Question 27

role of caesarian strip

Answer 27

blocks the apoplast pathway between cortex and medula ensuring water passes through cytoplasm

Question 28

what moves mineral ions from the cortex to the medula and xylem?

Answer 28

transporter proteins

Question 29

how does water move into the medula and xylem?

Answer 29

by osmosis and it cant pass back because it is blocked by the casparian strip

Question 30

what helps water move up the stem?

Answer 30

root pressure transpiration pull capillary action

Question 31

what is root pressure

Answer 31

endodermis moving minerals into the medulla pressure builds in root pushing water up xylem

Question 32

transpiration pull

Answer 32

loss of water through evaporation from leaves must be replaced and water molecules are attracted by cohesion

Question 33

capillary action?

Answer 33

water attracted to the sides of the xylem vessel through adhesion

Question 34

what is a hydrophite?

Answer 34

a plant adapted to living in water or where the ground is very wet

Question 35

what is a xerophyte?

Answer 35

a plant adapted to living in dry conditions l.

Question 36

terrestrial plants

Answer 36

reduce their water loss by structural and behavioural adaptations such as the waxy cuticle and losing leaves in winter.

Question 37

adaptations of marram grass

Answer 37

leaf rolled longitudinally so air is trapped inside making air humid. Thick waxy cuticle. stoma on inner side of rolled leaf.

Question 38

adaptations of cacti

Answer 38

store water in stems and it can expand leaves reduced to spines reducing surface area widespread roots

Question 39

adaptations of water lilly

Answer 39

many large air spaces keeping afloat | stomata on upper epidermis

Question 40

sink

Answer 40

part of the plant were materials are removed from the transport system e.g the roots

Question 41

source

Answer 41

part of plant that loads materials into the transport system e.g the leaves

Question 42

how is sucrose loaded into the sieve tube?

Answer 42

by an active process involving ATP

Question 43

what is cotransport?

Answer 43

active transport of hydrogen ions out of the companion cells creating a concentration gradient which brings them back into the companion cells with sucrose.

Question 44

how does sucrose get through plasmodesmata?

Answer 44

diffuses through when there is enough in the companion cells

Question 45

how does sucrose move along the phloem?

Answer 45

by mass flow

Question 46

what causes the flow of sap in the phloem?

Answer 46

difference in hydrostatic pressure between ends of tube creating pressure gradient.

Question 47

what causes an increases in hydrostatic pressure at the source?

Answer 47

osmosis of water into the sieve tube as a result of a decreased water potential due to the entrance of sucrose.

Question 48

why does water move out at the sink?

Answer 48

removal of sucrose increases water potential therefore water leaves trough osmosis