transport in plants (topic 8)

Question 1

function xylem

Answer 1

transporting water and dissolved mineral ions from the roots, through the stem and to the leaves
providing support for the plant and helping to keep it upright.

Question 2

function phloem

Answer 2

transport sucrose and amino acids

Question 3

structure of xylem and their adaptations for their function

Answer 3

thick walls with lignin for support
no cell content (hollow) and cells joined end to end with no cross walls to form a long continuous tube to transport water

Question 4

in roots how are phloem and xylem

Answer 4

x- xylem
phloem rest

Question 5

in stems how are phloem and xylem

Answer 5

xylem towards inside and phloem towards outside

Question 6

in a leaf vascular bundle

Answer 6

xylem on top phloem on bottom

Question 7

root hair cells

Answer 7

Type of cell in plant roots that has a large surface area for the absorption of water and mineral ions from the soil, increases surface area of root

Question 8

pathway of water in plants

Answer 8

soil- root hair cells- root hair cell cortex- xylem- stem- mesophyll cells- air spaces- stomata (as vapour)

Question 9

how can you investiagte the pathway of water in plants

Answer 9

cut celery stalk, place in water with food coloring, you should see the stain of the water movement in the stalk

Question 10

transpiration

Answer 10

the loss of water vapour from leaves

Question 11

how does water leave the leaf

Answer 11

evaporation at surface of spongy mesophyl cells to form water vapour evaporates to air spaces, and then diffuses out of the leaves through the stomata as water vapour

Question 12

what increases rate of transpiration and why

Answer 12

increasing temp, water molecules gain energy the rate of evaporation of water from the mesophyll cells increases the diffusion of water through the stomata increases the rate of transpiration increases.
wind speed increasing- wind removes water vapour from just outside the stomata so the diffusion gradient is maintained and water continues to diffuse out.

Question 13

what decreases rate of transpiration

Answer 13

humidity increasing- leaf is surrounded by moist air, the concentration gradient decreases resulting in less transpiration at a higher humidity.

Question 14

explain relationship between surface area, number of stomata, and transpiration

Answer 14

the bigger the surface area of a leaf, more stomata it contains, which results in a faster rate of transpiration

Question 15

explain transpiration pull

Answer 15

this is a suction force, draws water in xylem upwards from roots to leaves, that draws up a column of water molecules, held together by forces of attraction between
water molecules
cohesion- water molecules stick to each other
adhesion- force sticking water to xylem walls

Question 16

explain why and how wilting occurs

Answer 16

stems and leaves of young plants rely on turgicity o their plants to remain rigid, cell lose water, become flaccid losing rigidness and wilting
turgic cells are full of water, enough pressure against cell wall to keep plant upright
wilting happens when rate of transpiration is greater than absoprtion, plant cells lose water reducing tugor pressure, cells become flaccid and plant wilts

Question 17

translocation

Answer 17

the movement of sucrose and amino acids in phloem from sources to sinks

Question 18

sources

Answer 18

the parts of plants that release sucrose or amino acids

Question 19

sinks

Answer 19

region of storage or use in respiration or growth