lecture 6

Question 1

what part of the plant absorbs the most water

Answer 1

the root hairs

Question 2

what is the area of growth for the root

Answer 2

the root tip

Question 3

what are the two ways water moves throughout the plant

Answer 3

apoplast and symplast

Question 4

what is apoplast water movement (3 important things)

Answer 4

water travels through the CELLULOSE filled cell walls and intercellular spaces, h2o never cross a membrane, plant has no say over water movement in this pathway

Question 5

what is symplast water movement (three important things)

Answer 5

continuous water movement though the cytoplasm of cells CONNECTED by the plasmodesmata, plasma membrane controls movement (osmosis), plants have a say on what they want inside (REQUIRES ENERGY)

Question 6

what stops apoplast water movement

Answer 6

casparian strip

Question 7

what is the casparian strip

Answer 7

water impermeable (wax) sealing space in between cells and doesnt let water travel through cell walls

Question 8

what is the vascular tissue of a plant

Answer 8

xylem and phloem

Question 9

what is transpiration

Answer 9

movement of water vapor out of the leaf and into the atmosphere through the stomata

Question 10

what is evaporation

Answer 10

movement of water vapor from the cell walls of spongy mesophyll cells into the intercellular space

Question 11

is the movement of water vapor active or passive

Answer 11

passive

Question 12

what creates negative pressure in the leaf

Answer 12

when transpiration occurs, it deepens the meniscus of water in the leaf

Question 13

how does tension occur

Answer 13

created when transpiration pulls h20 molecules to fill the gap in the xylem drawing h20 upward

Question 14

what is cohesion

Answer 14

water sticking together

Question 15

what is adhesion

Answer 15

water sticking to other things

Question 16

what is the apical meristem

Answer 16

the location in which a plant grows , it grows at the top and it gets longer from the tips of the stems and the roots

Question 17

what are the three systems of a vascular plant

Answer 17

dermal, ground, vascular tissue

Question 18

in what plants are stomata found

Answer 18

mosses, hornworts, and vascular plants

Question 19

what happens when stomatas are opened

Answer 19

co2 is free to enter, o2 is free to leave, h2o evaporates an leaves the leaf tissue

Question 20

what happens when stomatas are closed

Answer 20

co2 can be depleted by photosynthesis , o2 can be accumulated and that inhibits photosynthesis, and h2o gets trapped in leaf

Question 21

how do stomata work in seed free, mosses, and some vascular plants

Answer 21

stomata opens when cells are turgid (full of water) and close when flaccid. when central vacuole is filled the cell has turgor pressure making it firm.

Question 22

how do stomata work in seed plants

Answer 22

a proton pump responds to light to change osmosis pressure potential of guard cells so that they swell and open (uses energy)

Question 23

what do stomata do during the day

Answer 23

stomata opens to allow co2 to enter

Question 24

what do stomata do during the night

Answer 24

stomata closes to conserve h2o

Question 25

where does stomata control water transport

Answer 25

through the xylem

Question 26

how do tall trees water their leaves

Answer 26

this process is controlled by evaporation and doesnt need energy, increased evaporation increases force and rate of h20 so water movement happens more on hot dry windy days

Question 27

when does evaporation ever stop

Answer 27

when theres no h2o in soil

Question 28

when does evaporation and transpiration occur mostly

Answer 28

on hot dry windy days rather than cool rainy days

Question 29

spermatophytes are

Answer 29

seed plants

Question 30

what is secondary growth

Answer 30

cell division that causes stems and roots to thicken

Question 31

what is primary growth

Answer 31

cell division that occurs at the tips of stems and roots

Question 32

what is wood

Answer 32

secondary xylem

Question 33

how is wood created

Answer 33

by secondary growth

Question 34

what two things are wood and bark derived from

Answer 34

2 lateral meristems

Question 35

what are the two lateral meristems

Answer 35

vascular cambium and cork cambium

Question 36

vascular cambium

Answer 36

produces secondary xylem (wood) and secondary phloem (inner bark)

Question 37

cork cambium

Answer 37

produces waxy walled protective cells , some die and become outer bark

Question 38

as you go to the center of the tree, what do you find

Answer 38

the older parts of the tree

Question 39

what does the vascular cambium do as the tree grows

Answer 39

the VC stops being in clusters of cells and becomes a cylinder making secondary xylem and secondary phloem expanding the diameter of the tree

Question 40

what does the cork cambium do

Answer 40

makes the cork cells that end up being bark

Question 41

what happens to the secondary xylem after a season has passed

Answer 41

the VC makes another secondary xylem by pushing it self outwards and the old secondary xylem becomes a ring inside of the tree

Question 42

what does the secondary xylem do

Answer 42

cannot carry water but allows support so that primary growth can occur

Question 43

what does the secondary phloem do

Answer 43

it has the live cells crush up against the cork cambium until it dies because only one secondary phloem can exist as the same time

Question 44

what is the difference between secondary xylem and secondary phloem

Answer 44

secondary xylem accumulates year after year while the secondary phloem gets crushed and dies