Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BISC 101 Mid2 > Plant Transport > Flashcards

Plant Transport Flashcards

Lecture 10

1
Q

Transpiration

A

loss of water from leaves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what does transpiration create?

A

a force that pulls xylem sap upwards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

where are water and minerals transported?

A

upwards from root to shoot in xylem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

roots absorb…

A

water and minerals from the soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

roots exchange…

A

gases with air spaces in soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

phloem sap function

A

transports sugars in both directions from site of production (leaves) to sites of storage (roots)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Water movement gradient (basically osmosis)

A

moves from areas of high water potential to low water potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

why is waters movement gradient the way it is?

A
  • due to solute concentration gradients
  • physical pressure exerted on water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Transport over short distances

A

occurs in the apoplast and symplast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

transport over long-distance

A

occurs via bulk flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the rate of transpiration regulated by

A

stomata (and their guard cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

where are sugars transported

A

from sources to sinks via the phloem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Solute potential meaning

A

tendency of water to move by osmosis in response to differences in solute concentrations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

isotonic solution solute concentrations are in what state?

A

in equilibrium meaning no net movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

water movement in hypotonic solution

A

moves into cell by osmosis
(low to high)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

cell volume in animal cell

A

increases until the cell bursts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

cell wall in plant cells

A

semi-rigid cell wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

pressure potential meaning

A

tendency of water to move in response to pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

turgor pressure function

A

keeps cell firm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are cells with no turgor pressure?

A

flacid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does water movement in plants depend on?

A

Combination of solute and pressure potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the endodermis

A

cyclindrical layer of cells forming a boundary between cortex and vascular tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what does the endodermis do?

A

controls ion uptake (selectively)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

pericycle meaning

A

cells can become meristematic; produce lateral roots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what is the casparian strip?
narrow band of water-repellent wax secreted by endodermis cell walls
26
what does the casparian strip do?
blocks the apoplastic route forcing water to move into cytoplasm of endodermal cells
27
what does the casparian strip act as?
- a filter letting K ions through but not Na ions
28
How do plant cells communicate directly?
via plasmodesmata
29
how do animal cells communicate?
via gap junctions
30
what type of movement do plants use?
passive and active transport
31
proton pumps function
primary role in plant transport processes and establishing membrane potentials
32
Ion channels function
can be gated; opening and closing in response to voltage, stretching of membrane, chemical factors, etc.
33
where is water potential high?
in soil
34
where is water potential medium-high
in roots
35
where is water potential low?
in leaves and the atmosphere
36
where is there a water potential gradient?
between roots and shoots
37
what are the 3 hypotheses for how water moves?
1) is water pushed against gravity by positive pressure in roots? 2) is water drawn up xylem cells by capillary action? 3) is water pulled up by a force generated in leaves?
38
Guttation meaning
excess water forced from leaves early in the morning
39
Does positive root pressure push water upwards against gravity in xylem tissue?
root pressure is only a minor mechanism. It's too weak to counter gravity over long distances
40
what is Surface tension?
downward pull that exists on water molecules at an air-water interface
41
what is Adhesion?
molecular attraction between water molecules and a solid substrate due to hydrogen bonding
42
what is Cohesion
molecular attraction between water molecules
43
Is water movement by capillary action possible?
capillary action can only move water over short distances
44
First step of transpirational pull
water vapour diffuses from moist air spaces to drier air
45
second step of transpirational pull
initially water is replaced from water film coating mesophyll cells
46
third step of transpirational pull
evaporation of water film causes water to retreat further into cell wall becoming curved
47
fourth step of transpirational pull
increased surface tension pulls water from surrounding cells and air spaces due to cohesion
48
fifth step of transpirational pull
water from the xylem is pulled into the surrounding cells and air spaces to replace the water that is lost
49
what water properties does transpirational pull depend on?
surface tension adhesion cohesion
50
what is the rate of transpiration regulated by?
stomatal density, and opening and closing
51
why do leaves have a large SA:vol?
to maximize absorption of sunlight for photosynthesis
52
what is wrong with leaves large SA:vol?
it increases water loss via stomata
53
what does stomatal number vary with?
leaf size/shape and season
54
what does stomatal density vary with?
environment and development
55
guard cells take up water to become...
turgid, and bow out = opening
56
guard cells lose water to become...
flaccid, and less bowed = closing
57
translocation meaning
movement of sugars through a plant from sources to sinks via the phloem
58
How is phloem sap transported?
bi-directionally in sieve-tube elements
59
where is phloem sap transported?
from sites of sugar production to sites of sugar use or storage
60
up to 30% of sap is what?
sucrose, AA's, hormones, minerals, mRNA's
61
What does sucrose moving into sieve tubes do?
reduces water potential inside the sieve-tube elements
62
what does the uptake of water do in the pressure-flow hypothesis
generates a positive (turgor) pressure which forces sap to flow along the sieve-tube
63
what happens at the sink unloading sucrose?
water moves into xylem and turgor pressure drops
64
what does a difference in turgor pressure do?
drives movement of phloem sap via bulk flow
65
what direction does sucrose have to be pumped?
against its concentration gradient
66
co-transporter function
uses the proton gradient to move sucrose into phloem cells against concentration gradient

BISC 101 Mid2 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions