Question 1

A plant will usually wilt when which component of water potential reaches 0 MPa?

Accepted Answer

A) solute potential 
B) turgor pressure 
C) total water potential 
D) gravity potential 
A) solute potential 
B) turgor pressure 
C) total water potential 
D) gravity potential

Question 2

Choose the letter of the best match from the following:
-Pore in plasma membrane that allows water movement.

Accepted Answer

A) abscisic acid 
B) trichomes 
C) aquaporin 
D) endodermis 
E) stomate 
A) abscisic acid 
B) trichomes 
C) aquaporin 
D) endodermis 
E) stomate

Question 3

To maintain guard cell turgor,which of the following must occur?

Accepted Answer

A) Potassium ions are pumped out. 
B) Energy is constantly expended. 
C) Water exits by osmosis. 
D) Stomata take up oxygen. 
E) Transpiration occurs. 
A) Potassium ions are pumped out. 
B) Energy is constantly expended. 
C) Water exits by osmosis. 
D) Stomata take up oxygen. 
E) Transpiration occurs.

Question 4

The uneven distribution of an impermeable solute on either side of a membrane will result in

Accepted Answer

A) an increase in oxygen deprivation. 
B) proton pumping. 
C) root pressure. 
D) osmosis. 
E) stomatal closing. 
A) an increase in oxygen deprivation. 
B) proton pumping. 
C) root pressure. 
D) osmosis. 
E) stomatal closing.

Question 5

Choose the letter of the best match from the following:
-Increases humidity at leaf surface.

Accepted Answer

A) abscisic acid 
B) trichomes 
C) aquaporin 
D) endodermis 
E) stomate 
A) abscisic acid 
B) trichomes 
C) aquaporin 
D) endodermis 
E) stomate

Question 6

Which of the following plant hormones plays a primary role in triggering K+ to pass rapidly out of guard cells?

Accepted Answer

A) gibberellic acid 
B) auxin 
C) indoleacetic acid 
D) ethylene 
E) abscisic acid 
A) gibberellic acid 
B) auxin 
C) indoleacetic acid 
D) ethylene 
E) abscisic acid

Question 7

Which of the following does not require expenditure of energy?

Accepted Answer

A) accumulation of ions inside a cell 
B) transport against a concentration gradient 
C) flow of sucrose and other carbohydrates through sieve tubes 
D) the loading and unloading of carbohydrates from the sieve tubes 
E) opening or closing stomata 
A) accumulation of ions inside a cell 
B) transport against a concentration gradient 
C) flow of sucrose and other carbohydrates through sieve tubes 
D) the loading and unloading of carbohydrates from the sieve tubes 
E) opening or closing stomata

Question 8

Most often,the largest gradient in water potential is between

Accepted Answer

A) roots and soil water. 
B) root xylem and shoot xylem. 
C) xylem and phloem. 
D) leaf cells and the intracellular spaces inside the leaves. 
E) the relative humidity inside the leaf and the relative humidity outside the plant. 
A) roots and soil water. 
B) root xylem and shoot xylem. 
C) xylem and phloem. 
D) leaf cells and the intracellular spaces inside the leaves. 
E) the relative humidity inside the leaf and the relative humidity outside the plant.

Question 9

The pressure-flow hypothesis describes

Accepted Answer

A) how hormones move through the phloem. 
B) how carbohydrates enter the sieve tubes. 
C) how carbohydrates in solution move through the phloem. 
D) how water and minerals move through the xylem. 
E) how carbohydrates and minerals move through the xylem. 
A) how hormones move through the phloem. 
B) how carbohydrates enter the sieve tubes. 
C) how carbohydrates in solution move through the phloem. 
D) how water and minerals move through the xylem. 
E) how carbohydrates and minerals move through the xylem.

Question 10

Which of these situations regarding phloem sources and sinks is not correct?

Accepted Answer

A) The seeds in a developing fruit are a strong sink. 
B) The shoot tip and young leaves are strong sources for the leaves below. 
C) Potentially,sugars could be transported from any part of a plant to any other part. 
D) In a seedling,the cotyledons would be strong sources. 
E) During autumn,one of the strongest sinks is the storage tissue in the roots. 
A) The seeds in a developing fruit are a strong sink. 
B) The shoot tip and young leaves are strong sources for the leaves below. 
C) Potentially,sugars could be transported from any part of a plant to any other part. 
D) In a seedling,the cotyledons would be strong sources. 
E) During autumn,one of the strongest sinks is the storage tissue in the roots.

Question 11

The most important ion in controlling the movement of water into and out of the guard cells is

Accepted Answer

A) sodium. 
B) hydrogen. 
C) carbon. 
D) nitrogen. 
E) potassium. 
A) sodium. 
B) hydrogen. 
C) carbon. 
D) nitrogen. 
E) potassium.

Question 12

Which of the following actions occurs in many plants when CO2 concentrations are high?

Accepted Answer

A) Guard cells lose turgor,and the stomata partially close. 
B) Water evaporates at a higher rate than usual. 
C) CAM photosynthesis fixes CO2 at night. 
D) Oxygen is used by plants for photosynthesis. 
E) Calcium ions are transported faster through the phloem. 
A) Guard cells lose turgor,and the stomata partially close. 
B) Water evaporates at a higher rate than usual. 
C) CAM photosynthesis fixes CO2 at night. 
D) Oxygen is used by plants for photosynthesis. 
E) Calcium ions are transported faster through the phloem.

Question 13

Even in the absence of transpiration,some water can move into the roots and partially up the xylem columns.This phenomenon is due to

Accepted Answer

A) flooding. 
B) stomatal opening. 
C) root pressure. 
D) proton pumps. 
E) phloem translocation. 
A) flooding. 
B) stomatal opening. 
C) root pressure. 
D) proton pumps. 
E) phloem translocation.

Question 14

Most of the water absorbed by the plant enters through the

Accepted Answer

A) root apical meristem. 
B) root cap. 
C) root hairs. 
D) stomata. 
E) lenticels. 
A) root apical meristem. 
B) root cap. 
C) root hairs. 
D) stomata. 
E) lenticels.

Question 15

Turgor is most directly related to the plant cells'

Accepted Answer

A) total water potential. 
B) pressure potential. 
C) solute potential. 
D) osmosis. 
E) gravity potential. 
A) total water potential. 
B) pressure potential. 
C) solute potential. 
D) osmosis. 
E) gravity potential.

Question 16

In Cell 2,

Accepted Answer

A) $\Psi$p = 0.75 MPa and $\Psi$w = 0.0 MPA. 
B) $\Psi$p = 0.0 MPa and $\Psi$w = -0.75 MPa. 
C) $\Psi$p = -0.25 MPa and $\Psi$w = -0.5 MPa. 
D) $\Psi$p = +0.25 MPa and $\Psi$w = -0.5 MPa. 
E) $\Psi$p = +0.25 MPa and $\Psi$w = +0.25 MPa. 
A) $\Psi$p = 0.75 MPa and $\Psi$w = 0.0 MPA. 
B) $\Psi$p = 0.0 MPa and $\Psi$w = -0.75 MPa. 
C) $\Psi$p = -0.25 MPa and $\Psi$w = -0.5 MPa. 
D) $\Psi$p = +0.25 MPa and $\Psi$w = -0.5 MPa. 
E) $\Psi$p = +0.25 MPa and $\Psi$w = +0.25 MPa.

Question 17

Water molecules can "stick" to certain surfaces by

Accepted Answer

A) adhesion. 
B) cohesion. 
C) root pressure. 
D) water pressure. 
E) pneumatophores. 
A) adhesion. 
B) cohesion. 
C) root pressure. 
D) water pressure. 
E) pneumatophores.

Question 18

Which of the following statements about transport through phloem is true?

Accepted Answer

A) Transport only occurs from the roots to the shoot. 
B) It is aided by root pressure. 
C) The direction of flow can change at different times if the sources and sinks change. 
D) No energy is requireD. 
E) Mostly dissolved starch is transported. 
A) Transport only occurs from the roots to the shoot. 
B) It is aided by root pressure. 
C) The direction of flow can change at different times if the sources and sinks change. 
D) No energy is requireD. 
E) Mostly dissolved starch is transported.

Question 19

Plants living in standing water often face which of the following problems?

Accepted Answer

A) increased CO2 levels 
B) chilling of the roots 
C) oxygen deprivation 
D) loss of stomata 
E) harmful root pressure 
A) increased CO2 levels 
B) chilling of the roots 
C) oxygen deprivation 
D) loss of stomata 
E) harmful root pressure

Question 20

On a short-term basis,water loss in plants may be controlled by the

Accepted Answer

A) bending of the petioles on the leaves. 
B) closing of the stele in the roots. 
C) closing of the stomates in the leaves to limit transpiration. 
D) opening of the stomates in the leaves to allow more carbon dioxide to enter. 
E) opening the casparian strips in the roots. 
A) bending of the petioles on the leaves. 
B) closing of the stele in the roots. 
C) closing of the stomates in the leaves to limit transpiration. 
D) opening of the stomates in the leaves to allow more carbon dioxide to enter. 
E) opening the casparian strips in the roots.

Exam 38: Transport in Plants

A plant will usually wilt when which component of water potential reaches 0 MPa?

Choose the letter of the best match from the following: -Pore in plasma membrane that allows water movement.

To maintain guard cell turgor,which of the following must occur?

The uneven distribution of an impermeable solute on either side of a membrane will result in

Choose the letter of the best match from the following: -Increases humidity at leaf surface.

Which of the following plant hormones plays a primary role in triggering K+ to pass rapidly out of guard cells?

Which of the following does not require expenditure of energy?

Most often,the largest gradient in water potential is between

The pressure-flow hypothesis describes

Which of these situations regarding phloem sources and sinks is not correct?

The most important ion in controlling the movement of water into and out of the guard cells is

Which of the following actions occurs in many plants when CO2 concentrations are high?

Even in the absence of transpiration,some water can move into the roots and partially up the xylem columns.This phenomenon is due to

Most of the water absorbed by the plant enters through the

Turgor is most directly related to the plant cells'

In Cell 2,

Water molecules can "stick" to certain surfaces by

Which of the following statements about transport through phloem is true?

Plants living in standing water often face which of the following problems?

On a short-term basis,water loss in plants may be controlled by the

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Which of the following plant hormones plays a primary role in triggering K⁺ to pass rapidly out of guard cells?

Which of the following actions occurs in many plants when CO₂ concentrations are high?