13 - Plant Transport

Question 1

How do roots take up all of the ions that are in the soild? the plant is hypertonic to the soil so there is a concentration gradient

Answer 1

specifically creates a charge gradient, the plant activel exports H⁺ nions from the cell via an ATP pump, there fore causeing the intracellular charge of the cell to become electronegative drawing in cations through diffusion throught the transmb channel

Question 2

how do roots uptake negatively charged molecules like NO₃^-

Answer 2

through an H⁺ cotransporter the NO₃^- goes up its concentration gradient, as wll as large molecules like sugar + H⁺

Question 3

Why does H₂O move through the plant?

during the day?

Night?

Answer 3

negative pressure during the day b/c of evaporation

night = ionic concentration in root cells = osmotic pull

Answer 4

7 - epidermis

8 - cortex

9 - endodermis

10 - parenchyma

11 - phloem

12 - Xylem

13 - pith

Question 5

How is the arrangement of vascular tissue different in monocot and dicot stems?

Answer 5

In monocots, vascular bundles are scattered throughout the ground tissue, with many at the periphery and decreasing numbers toward the center of the stem. By contrast, the vascular bundles in dicots are arranged in a single ring toward the periphery of the stem, with none in the center.

Question 6

How is the arrangement of vascular tissues in a monocot root different from a dicot root?

Answer 6

In monocots, the vascular bundle has a central pith, which is surrounded by a cylinder of xylem, surrounded by a cylinder of phloem. By contrast in the vascular bundle of a dicot the xylem is a star-shaped, centrally located column with strands of phloem located between the arms or points of the xylem.

Question 7

Potatoes contain food in the form of starch, which ground tissue are you eating when you eat mashed potatoes?

Answer 7

parenchyma

Question 8

The part of rhubarb that people eat is the petiole of a large leaf. Which tissue provides support for rhubarb?

Answer 8

collenchyma

Question 9

Which ground tissue is a major component of the blades of spinach leaves?

Answer 9

parenchyma

Question 10

Which ground tissue makes the shell of a nut hard?

Answer 10

sclerenchyma

Question 11

The _____________ prevents substances from leaking back out of teh xylem

Answer 11

casperian strip

Question 12

describe the casperian strip

Answer 12

waxy

impenitrable via transmb route or apoplastic route

acts as a guard for the roots

Question 13

list the three routes that water and minerals get into roots, which one is the most direct

Answer 13

1. apoplastic - through the cellular walls - doesn’t get direct access
2. symplastic - through the plasmodesmata - direct route
3. transmembrane - accross cells - not direct

Question 14

The ___________ route gains minerals and water entry though the casparian strip via ___________

Answer 14

symplastic

plasmodesmata

Question 15

Why doesnt the plant have its casparian strip just inside of the pidermis versus the endodermis?

Answer 15

it increases the surface area of absorption

Question 16

How does the concentration of potassium affect guard cells?

Answer 16

• stomata opening and closing as the ions enter and leave the stomata bring along with it H2O.
• the movement of the K⁺ ions brings with it water, and is caused by light changes
• this is under hormonal control

Question 17

Define transpiration

Answer 17

• water evaporation via xylem cohesion and adhesion to the polar cllulose of the walls of the X
• also keeps the temp regulated of the plant

Question 18

where are the sinks of the plant?

Answer 18

growing things -

also storage for excess

Question 19

Define translocation

Answer 19

movement in Phloem of sugars hormoes from sourse to sink

the bulk flow is facilitaed by positive pressure

Question 20

Where is the source cell for sugar production

Answer 20

where chlorophyll is taking sunlight and turning it inot sugar

Question 21

what is the difference b/t the mech of bulk transport oin xylem vs phloem?

Answer 21

X = negative pressure

P = positive pressure

Question 22

A water molecule could move all the way through a plant from soil to root to leaf to air and pass through a living cell only once. This living cell would be a part of which structure?
Select one:
A. The root cortex
B. A guard cell
C. The root epidermis
D. The casparian strip
E. The endodermis

Answer 22

The endodermis

Question 23

Which of the following is NOT part of the transpiration-cohesion-tension mechanism?
Select one:
A. Water is remarkably cohesive
B. Removal of water from the xylem exerts a pull on the water column
C. Water evaporates from the walls of mesophyll cells
D. The high pressure created by the K+ concentration gradient aids in the pull on the water column

Answer 23

The high pressure created by the K+ concentration gradient aids in the pull on the water column

Question 24

Which statement about phloem transport is NOT true?

Select one:
A. Phloem sap flows due to pressure
B. The location of the source and sink can change
C. At the sink solute is always actively transported
D. At the sink water returns to the xylem

Answer 24

At the sink solute is always actively transported

Question 25

Which statement is NOT true?
Select one:
A. Water can move freely in the apoplast without entering cells
B. The symplast consists of the interconnected cytoplasm of living cells
C. The endodermis is a cell layer in the cortex
D. The casparian strip prevents water from moving between endodermal cells by the apoplast
E. Water can enter the stele (cylinder of vascular tissue in the stem) without entering the symplast

Answer 25

Water can enter the stele (cylinder of vascular tissue in the stem) without entering the symplast

Question 26

Proton pumps in the plasma membranes of plant cells may

Select one:
A. Are involved in the movement of K+ into guard cells
B. Contribute to the movement of anions through a cotransport mechanism
C. All answers apply
D. Generate a membrane potential that helps drive cations into the cell through their specific channels

Answer 26

all answers apply

Question 27

In the xylem,
Select one:
A. The products of photosynthesis travel down the stem
B. Living cells pump the sap upwards
C. Roots drive the force of sap movement
D. The sap is under tension

Answer 27

The sap is under tension

Question 28

What would enhance water uptake by a plant cell?

Select one:

a. positive pressure on the surrounding solution
b. the loss of solutes from the cell
c. increasing the pressure exerted by the cell wall
d. decreasing the water potential of the surrounding solution
e. increasing the water potential of the cytoplasm

Answer 28

positive pressure on the surrounding solution