Question 1

If a plant cell is placed in a solution whose solute concentration is lower than that inside the cell, the cell will

Accepted Answer

A)  wilt. 
B)  take up water. 
C)  take up solute. 
D)  divide. 
E)  shrink. 
A)  wilt. 
B)  take up water. 
C)  take up solute. 
D)  divide. 
E)  shrink. B

Question 2

_______ is primarily responsible for maintaining one continuous column of water within the xylem.

Accepted Answer

Cohesion

Question 3

Assume that two chambers of water are separated by a permeable membrane.The two chambers are under identical conditions, except that on one side of the membrane there is pure water, and on the other side there is a sucrose solution (i.e., sucrose dissolved in water).From measurements you determine that the side with the solution has a solute potential (F1F1F1S1F1F1F10s) of -2.3 MPa.Which of the following is also likely to be true?

Accepted Answer

A)  There will be no net movement of water. 
B)  For the side with the sucrose solution, F1F1F1S1F1F1F10p = 2.3 MPa. 
C)  For the side with the sucrose solution, F1F1F1S1F1F1F10total = -2.3 MPa. 
D)  For the side with the pure water, F1F1F1S1F1F1F10p = -2.3 MPa. 
E)  For the side with the pure water F1F1F1S1F1F1F10s = -2.3 MPa. 
A)  There will be no net movement of water. 
B)  For the side with the sucrose solution, F1F1F1S1F1F1F10p = 2.3 MPa. 
C)  For the side with the sucrose solution, F1F1F1S1F1F1F10total = -2.3 MPa. 
D)  For the side with the pure water, F1F1F1S1F1F1F10p = -2.3 MPa. 
E)  For the side with the pure water F1F1F1S1F1F1F10s = -2.3 MPa. C

Question 4

Transpiration is principally due to

Accepted Answer

A)  the flow of water into the roots by osmosis. 
B)  xylem pressure in the stem. 
C)  capillary action. 
D)  the continuity of the water column. 
E)  a large, negative water potential difference between water in the leaf and water in the atmosphere. 
A)  the flow of water into the roots by osmosis. 
B)  xylem pressure in the stem. 
C)  capillary action. 
D)  the continuity of the water column. 
E)  a large, negative water potential difference between water in the leaf and water in the atmosphere.

Question 5

In which of the following conditions do plants close their stomata?

Accepted Answer

A)  Bright sunlight 
B)  Water stress 
C)  Low CO2 
D)  Lack of wind 
E)  Warm temperatures 
A)  Bright sunlight 
B)  Water stress 
C)  Low CO2 
D)  Lack of wind 
E)  Warm temperatures

Question 6

Increasing the flow of photosynthate to sinks is being investigated in agricultural systems as a mechanism for increasing the supply of

Accepted Answer

A)  food. 
B)  mineral nutrients. 
C)  water. 
D)  chlorophyll. 
E)  glucose. 
A)  food. 
B)  mineral nutrients. 
C)  water. 
D)  chlorophyll. 
E)  glucose.

Question 7

The opening and closing of guard cells is most directly determined by uptake and release of

Accepted Answer

A)  Br-. 
B)  K+. 
C)  Na+. 
D)  Mg2+. 
E)  H+. 
A)  Br-. 
B)  K+. 
C)  Na+. 
D)  Mg2+. 
E)  H+.

Question 8

Translocation results from the _______ transport of sucrose into the _______.

Accepted Answer

A)  passive; phloem at a source 
B)  active; xylem 
C)  active; phloem at a source 
D)  active; phloem at a sink 
E)  passive; xylem 
A)  passive; phloem at a source 
B)  active; xylem 
C)  active; phloem at a source 
D)  active; phloem at a sink 
E)  passive; xylem

Question 9

Active transport enables K+ ions to move again the concentration gradient because

Accepted Answer

A)  they are coupled with H+ ions. 
B)  they are transported via proton pumps. 
C)  they are propelled by diffusion. 
D)  the electrical gradient causes them to enter the cell. 
E)  ATP-powered pumps move them into the cell. 
A)  they are coupled with H+ ions. 
B)  they are transported via proton pumps. 
C)  they are propelled by diffusion. 
D)  the electrical gradient causes them to enter the cell. 
E)  ATP-powered pumps move them into the cell.

Question 10

All of the following stimulate stomata to open in most plants except

Accepted Answer

A)  low CO2 levels within the leaf. 
B)  sunlight. 
C)  entry of K+ into guard cells. 
D)  low levels of abscisic acid. 
E)  loss of water from guard cells. 
A)  low CO2 levels within the leaf. 
B)  sunlight. 
C)  entry of K+ into guard cells. 
D)  low levels of abscisic acid. 
E)  loss of water from guard cells.

Question 11

The uptake of ions in plant cells is influenced by all of the following except

Accepted Answer

A)  electrical gradient. 
B)  concentration gradient. 
C)  ionic balance. 
D)  the pumping of H+. 
E)  cell wall rigidity. 
A)  electrical gradient. 
B)  concentration gradient. 
C)  ionic balance. 
D)  the pumping of H+. 
E)  cell wall rigidity.

Question 12

The opening of stomata in the light involves _______, and their closing in the dark involves _______.

Accepted Answer

A)  diffusion of K+ into guard cells; passive efflux of K+ from guard cells 
B)  passive uptake of K+ by guard cells; active efflux of K+ from guard cells 
C)  active uptake of H+ by guard cells; passive efflux of H+ from guard cells 
D)  uptake of water from guard cells; loss of water by guard cells 
E)  active pumping of H+ into guard cells; diffusion of Cl- out of guard cells 
A)  diffusion of K+ into guard cells; passive efflux of K+ from guard cells 
B)  passive uptake of K+ by guard cells; active efflux of K+ from guard cells 
C)  active uptake of H+ by guard cells; passive efflux of H+ from guard cells 
D)  uptake of water from guard cells; loss of water by guard cells 
E)  active pumping of H+ into guard cells; diffusion of Cl- out of guard cells

Question 13

Which of the following is true regarding the distinction between monocots and eudicots, with respect to controlling leaf gas exchange?

Accepted Answer

A)  Monocots do not have a system for controlling leaf gas exchange. 
B)  Eudicots lack stomata. 
C)  Monocots lack guard cells. 
D)  Monocots and eudicots have fundamentally the same strategy for controlling leaf gas exchange. 
E)  Monocots lack the specialized epidermal cells that eudicots possess. 
A)  Monocots do not have a system for controlling leaf gas exchange. 
B)  Eudicots lack stomata. 
C)  Monocots lack guard cells. 
D)  Monocots and eudicots have fundamentally the same strategy for controlling leaf gas exchange. 
E)  Monocots lack the specialized epidermal cells that eudicots possess.

Question 14

You are working on a self-directed lab for an online-only general biology course.The instructions say to apply a stain to a section of spinach leaf, and that this stain will form color only in the apoplast.Which of the following will be colored?

Accepted Answer

A)  Cell walls 
B)  Plasma membranes 
C)  Plasmodesmata 
D)  Cytoplasm 
E)  Vacuoles 
A)  Cell walls 
B)  Plasma membranes 
C)  Plasmodesmata 
D)  Cytoplasm 
E)  Vacuoles

Question 15

Refer to the table below.   Assume that the table indicates water potential for a number of locations inside a healthy tree.Given the data, what can you conclude?

Accepted Answer

A)  The tree has a wound of some sort in the trunk. 
B)  There is no water flowing through the xylem. 
C)  Water is flowing in the wrong direction. 
D)  There seems to be minimal transpiration taking place. 
E)  There does not seem to be adequate cohesion drawing the water through the tree. 
A)  The tree has a wound of some sort in the trunk. 
B)  There is no water flowing through the xylem. 
C)  Water is flowing in the wrong direction. 
D)  There seems to be minimal transpiration taking place. 
E)  There does not seem to be adequate cohesion drawing the water through the tree.

Question 16

A researcher uses aphid stylets to collect the phloem sap from 27 different families of flowering plants.The most commonly found sugar in the phloem is likely to be

Accepted Answer

A)  glucose. 
B)  xylose. 
C)  sucrose. 
D)  ribulose. 
E)  ribose. 
A)  glucose. 
B)  xylose. 
C)  sucrose. 
D)  ribulose. 
E)  ribose.

Question 17

Tension can develop in a column of water because water molecules are

Accepted Answer

A)  tensile. 
B)  cohesive. 
C)  covalent. 
D)  linear. 
E)  adhesive. 
A)  tensile. 
B)  cohesive. 
C)  covalent. 
D)  linear. 
E)  adhesive.

Question 18

According to the theory of transpirationF1F1F1S1F1F1F10cohesionF1F1F1S1F1F1F10tension, what forces in addition to these three are needed to draw water through the xylem?

Accepted Answer

A)  None 
B)  Gravity 
C)  Active transport 
D)  Capillary action 
E)  Root contraction 
A)  None 
B)  Gravity 
C)  Active transport 
D)  Capillary action 
E)  Root contraction

Question 19

The fact that there is one continuous column of water within the xylem is best explained by

Accepted Answer

A)  transpiration. 
B)  differences in pressure potential. 
C)  the force of gravity pushing down on the water column. 
D)  the force of cohesion. 
E)  osmosis drawing water into the xylem. 
A)  transpiration. 
B)  differences in pressure potential. 
C)  the force of gravity pushing down on the water column. 
D)  the force of cohesion. 
E)  osmosis drawing water into the xylem.

Question 20

Aquaporins

Accepted Answer

A)  actively pump water into the cell. 
B)  facilitate movement of water across the plasma membrane. 
C)  reverse the direction of osmosis. 
D)  are needed for the apoplastic transport of water in roots. 
E)  move water against the pressure gradient. 
A)  actively pump water into the cell. 
B)  facilitate movement of water across the plasma membrane. 
C)  reverse the direction of osmosis. 
D)  are needed for the apoplastic transport of water in roots. 
E)  move water against the pressure gradient.

Exam 34: Transport in Plants

If a plant cell is placed in a solution whose solute concentration is lower than that inside the cell, the cell will

_______ is primarily responsible for maintaining one continuous column of water within the xylem.

Transpiration is principally due to

In which of the following conditions do plants close their stomata?

Increasing the flow of photosynthate to sinks is being investigated in agricultural systems as a mechanism for increasing the supply of

The opening and closing of guard cells is most directly determined by uptake and release of

Translocation results from the _______ transport of sucrose into the _______.

Active transport enables K+ ions to move again the concentration gradient because

All of the following stimulate stomata to open in most plants except

The uptake of ions in plant cells is influenced by all of the following except

The opening of stomata in the light involves _______, and their closing in the dark involves _______.

Which of the following is true regarding the distinction between monocots and eudicots, with respect to controlling leaf gas exchange?

You are working on a self-directed lab for an online-only general biology course.The instructions say to apply a stain to a section of spinach leaf, and that this stain will form color only in the apoplast.Which of the following will be colored?

Refer to the table below. Assume that the table indicates water potential for a number of locations inside a healthy tree.Given the data, what can you conclude?

A researcher uses aphid stylets to collect the phloem sap from 27 different families of flowering plants.The most commonly found sugar in the phloem is likely to be

Tension can develop in a column of water because water molecules are

According to the theory of transpirationcohesiontension, what forces in addition to these three are needed to draw water through the xylem?

The fact that there is one continuous column of water within the xylem is best explained by

Aquaporins

Studying Life

Small Molecules and the Chemistry of Life

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Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

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Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

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Translocation results from the _ transport of sucrose into the _.

Active transport enables K⁺ ions to move again the concentration gradient because

The opening of stomata in the light involves _, and their closing in the dark involves _.