Question 1

Formation of the curved upper surface, such as occurs in a tube filled with water, is an important factor in plant water movement. A curved upper surface is created by ________.

Accepted Answer

A)   the upward pull of gravity on the water column in the tube
B)   downward pressure from the atmosphere on the topmost layer of water molecules
C)   the water molecules being pulled upward by adhesion to the air
D)   the topmost layer of water molecules being pulled downward by the hydrogen bonds to the water molecules below D

Question 2

One is most likely to see guttation in small plants when the ________.

Accepted Answer

A)   transpiration rates are high
B)   root pressure exceeds transpiration pull
C)   preceding evening was hot, windy, and dry
D)   roots are not absorbing minerals from the soil B

Question 3

If isolated plant cells with a water potential averaging -0.5 MPa are placed into a solution with a water potential of -0.3 MPa, which of the following would be the most likely outcome?

Accepted Answer

A)   The pressure potential of the cells would increase.
B)   Water would move out of the cells.
C)   The cell walls would rupture, killing the cells.
D)   Solutes would move out of the cells. A

Question 4

A fellow student brought in a leaf to be examined. The leaf was dark green, thin, had stoma on the lower surface only, and had a total surface area of ten square meters. Where is the most likely environment where this leaf was growing?

Accepted Answer

A)   a large, still pond
B)   a tropical rain forest
C)   an oasis within a grassland
D)   the floor of a deciduous forest

Question 5

When an animal cell is placed in a hypotonic solution and water enters the cell via osmosis, the volume of the cell increases until it bursts. This does not happen to plant cells, because ________.

Accepted Answer

A)   they have large central vacuoles, which provide abundant space for storage of incoming water
B)   they have cell walls, which prevent the entry of water by osmosis
C)   they have cell walls, which provide pressure to counteract the pressure of the incoming water
D)   certain gated channel proteins embedded in their plasma membranes open as osmotic pressure decreases, allowing excess water to leave the cell

Question 6

Which of following ions play the primary role in basic transport processes in plant cells?

Accepted Answer

A)   H⁺
B)   Na⁺
C)   K⁺
D)   Ca⁺²

Question 7

Given that early land plants most likely share a common ancestor with green algae, the earliest land plants were most likely ________.

Accepted Answer

A)   nonvascular plants that grew leafless, photosynthetic shoots
B)   species that did not exhibit alternation of generations
C)   vascular plants with well-defined root systems
D)   plants with well-developed leaves

Question 8

In the transmembrane route for transport within plant tissue, ________.

Accepted Answer

A)   water and solutes move out of one cell, across the cell wall, and into the neighboring cell
B)   water and solutes move out of one cell, through the plasmodesmata, and into the neighboring cell
C)   water moves out of one cell, across the cell wall, and into the neighboring cell
D)   solutes move out of one cell, across the plasmodesmata, and into the neighboring cell

Question 9

How does a flaccid cell differ from a turgid cell?

Accepted Answer

A)   A flaccid cell has higher pressure potential.
B)   A flaccid cell has lower pressure potential.
C)   A flaccid cell has higher solute potential.
D)   A flaccid cell has lower solute potential.

Question 10

A plant cell with a ΨS of -0.65 MPa maintains a constant volume when bathed in a solution that has a ΨS of -0.30 MPa and is in an open container. The cell has a

Accepted Answer

A)   ΨP of +0.65 MPa.
B)   Ψ of -0.65 MPa.
C)   ΨP of +0.35 MPa.
D)   ΨP of 0 MPa.

Question 11

In xerophytes, ________ are referred to as crypts.

Accepted Answer

A)   stomata recessed in cavities
B)   guard cells
C)   hairs (trichomes) 
D)   lower epidermal cells

Question 12

Compared with a cell with few aquaporin proteins in its membrane, a cell containing many aquaporin proteins will

Accepted Answer

A)   have a faster rate of osmosis.
B)   have a lower water potential.
C)   have a higher water potential.
D)   accumulate water by active transport.

Question 13

The protoplast consists of ________.

Accepted Answer

A)   all cell components without a nucleus
B)   all cell components without a cell membrane
C)   only the cytoplasm and nucleus
D)   the living part of the cell, including the cell membrane

Question 14

If ΨP = 0.3 MPa and ΨS = -0.45 MPa, the resulting Ψ is ________.

Accepted Answer

A)   +0.75 MPa
B)   -0.75 MPa
C)   -0.15 MPa
D)   +0.15 MPa

Question 15

Solute potential in a cell is also called ________.

Accepted Answer

A)   water potential
B)   osmotic potential
C)   potential gradient
D)   pressure potential

Question 16

What is the overall charge on the cytoplasmic side of a plant cell plasma membrane?

Accepted Answer

A)   positive
B)   negative
C)   neutral

Question 17

Which one of the following statements about transport of nutrients in phloem is correct?

Accepted Answer

A)   Solute particles are actively transported from phloem at the source.
B)   Companion cells control the rate and direction of movement of phloem sap.
C)   Differences in osmotic concentration at the source and sink cause a hydrostatic pressure gradient to be formed.
D)   A sink is the part of a plant where a particular solute is produced.

Question 18

Some botanists argue that the entire plant should be considered as a single unit rather than a composite of many individual cells. Which of the following cellular structures best supports this view?

Accepted Answer

A)   cell wall
B)   cell membrane
C)   vacuole
D)   plasmodesmata

Question 19

Which structure or compartment is separate from the apoplastic route?

Accepted Answer

A)   the lumen of a xylem vessel
B)   the lumen of a sieve tube
C)   the cell wall of a mesophyll cell
D)   the cell wall of a root hair

Question 20

The leaf area index is the ratio of the ________.

Accepted Answer

A)   upper leaf surface of a single plant divided by the surface area of the land on which the plant grows
B)   lower leaf surface of a single plant divided by the surface area of the land on which the plant grows
C)   upper leaf surface of a single plant multiplied by the surface area of the land on which the plant grows
D)   lower leaf surface of a single plant multiplied by the surface area of the land on which the plant grows

Exam 36: Resource Acquisition and Transport in Vascular Plants