Question 1

In the process of guttation, water is exuded from leaves through hydathodes.

Accepted Answer

A) True 
 B)False  True

Question 2

Which of the following is/are present in the highest concentration in sieve-tube sap?

Accepted Answer

A)  glucose 
B)  amino acids 
C)  magnesium 
D)  sorbitol 
E)  sucrose 
A)  glucose 
B)  amino acids 
C)  magnesium 
D)  sorbitol 
E)  sucrose E

Question 3

It is the smallest pores in the walls or pit membranes of vessels or tracheids that are the most susceptible to air seeding.

Accepted Answer

A) True 
 B)False  False

Question 4

Which of the following is NOT evidence supporting the role of phloem in sugar transport?

Accepted Answer

A)  Honeydew contains amino acids but not sucrose. 
B)  14C-labeled sucrose is transported in sieve tubes. 
C)  The exudate from the stylets of feeding aphids is mainly sucrose. 
D)  Radioactive assimilates are transported in the phloem. 
E)  When a tree is girdled, the bark above the ring becomes swollen. 
A)  Honeydew contains amino acids but not sucrose. 
B)  14C-labeled sucrose is transported in sieve tubes. 
C)  The exudate from the stylets of feeding aphids is mainly sucrose. 
D)  Radioactive assimilates are transported in the phloem. 
E)  When a tree is girdled, the bark above the ring becomes swollen.

Question 5

In the process of stomatal movement, blue light activates a proton pump in the plasma membrane of the guard cell.

Accepted Answer

A) True 
 B)False

Question 6

Which of the following statements about sources and sinks in assimilate movement is FALSE?

Accepted Answer

A)  A plant part unable to meet its nutritional needs functions as a sink. 
B)  In seedlings, the cotyledons commonly act as the major sinks. 
C)  In mature plants, the upper leaves commonly act as sources for the shoot apex. 
D)  In mature plants, the lower leaves commonly act as sources for the roots. 
E)  Developing fruits are highly competitive sinks. 
A)  A plant part unable to meet its nutritional needs functions as a sink. 
B)  In seedlings, the cotyledons commonly act as the major sinks. 
C)  In mature plants, the upper leaves commonly act as sources for the shoot apex. 
D)  In mature plants, the lower leaves commonly act as sources for the roots. 
E)  Developing fruits are highly competitive sinks.

Question 7

Radial micellation refers to the ______ of guard cells.

Accepted Answer

A)  shape 
B)  opening and closing 
C)  orientation of proteins in the plasma membrane 
D)  orientation of cellulose microfibrils in the cell walls 
E)  mode of attachment between the ends 
A)  shape 
B)  opening and closing 
C)  orientation of proteins in the plasma membrane 
D)  orientation of cellulose microfibrils in the cell walls 
E)  mode of attachment between the ends

Question 8

In the process of stomatal closing, which of the following events occurs first?

Accepted Answer

A)  Water moves out of guard cells. 
B)  Water moves into guard cells. 
C)  Guard cell turgor pressure decreases. 
D)  Guard cell solute concentration declines. 
E)  Guard cell water potential increases. 
A)  Water moves out of guard cells. 
B)  Water moves into guard cells. 
C)  Guard cell turgor pressure decreases. 
D)  Guard cell solute concentration declines. 
E)  Guard cell water potential increases.

Question 9

Phototropins are:

Accepted Answer

A)  osmoticums. 
B)  photoreceptors. 
C)  microfibrils. 
D)  enzymes. 
E)  active-transport proteins. 
A)  osmoticums. 
B)  photoreceptors. 
C)  microfibrils. 
D)  enzymes. 
E)  active-transport proteins.

Question 10

The driving force for assimilate transport is:

Accepted Answer

A)  diffusion. 
B)  active transport. 
C)  transpiration. 
D)  osmosis. 
E)  pressure-flow. 
A)  diffusion. 
B)  active transport. 
C)  transpiration. 
D)  osmosis. 
E)  pressure-flow.

Question 11

Mycorrhizae are especially important in the plant's absorption of:

Accepted Answer

A)  zinc. 
B)  phosphorus. 
C)  manganese. 
D)  copper. 
E)  iron. 
A)  zinc. 
B)  phosphorus. 
C)  manganese. 
D)  copper. 
E)  iron.

Question 12

Which of the following statements about stomatal movements is FALSE?

Accepted Answer

A)  An increase in CO2 levels usually causes stomata to close. 
B)  Sensors for carbon dioxide are located in guard cells. 
C)  Stomatal opening and closing exhibit circadian rhythms. 
D)  Cacti and pineapple open their stomata at night. 
E)  Temperatures above 30°-35°F usually stimulate stomatal opening. [OK to add F?] 
A)  An increase in CO2 levels usually causes stomata to close. 
B)  Sensors for carbon dioxide are located in guard cells. 
C)  Stomatal opening and closing exhibit circadian rhythms. 
D)  Cacti and pineapple open their stomata at night. 
E)  Temperatures above 30°-35°F usually stimulate stomatal opening. [OK to add F?]

Question 13

A dry breeze increases the rate of transpiration mainly because it:

Accepted Answer

A)  cools the leaf. 
B)  warms the leaf. 
C)  increases the CO2 gradient across the leaf surface. 
D)  decreases the CO2 gradient across the leaf surface. 
E)  increases the vapor pressure difference across the leaf surface. 
A)  cools the leaf. 
B)  warms the leaf. 
C)  increases the CO2 gradient across the leaf surface. 
D)  decreases the CO2 gradient across the leaf surface. 
E)  increases the vapor pressure difference across the leaf surface.

Question 14

The polymer trapping mechanism is a symplastic loading mechanism.

Accepted Answer

A) True 
 B)False

Question 15

Nocturnal transpiration occurs in CAM plants but not C3 plants.

Accepted Answer

A) True 
 B)False

Question 16

In vascular plants, hydraulic redistribution is the:

Accepted Answer

A)  movement of water from roots to leaves. 
B)  flow of water against a water potential gradient. 
C)  movement of water across the endodermis. 
D)  transfer of water across Casparian strips. 
E)  transfer of water by roots from moist to dry regions of the soil. 
A)  movement of water from roots to leaves. 
B)  flow of water against a water potential gradient. 
C)  movement of water across the endodermis. 
D)  transfer of water across Casparian strips. 
E)  transfer of water by roots from moist to dry regions of the soil.

Question 17

The transport of the assimilate stream in the phloem is called translocation.

Accepted Answer

A) True 
 B)False

Question 18

Which of the following does NOT provide evidence supporting the cohesion-tension theory?

Accepted Answer

A)  Water has sufficient tensile strength. 
B)  The water potential in a stem is sufficient. 
C)  In the morning, heated water begins to flow close to the leaves. 
D)  In the morning, the diameter of a tree decreases first in the upper trunk. 
E)  In the evening, the diameter of a tree increases first in the lower trunk. 
A)  Water has sufficient tensile strength. 
B)  The water potential in a stem is sufficient. 
C)  In the morning, heated water begins to flow close to the leaves. 
D)  In the morning, the diameter of a tree decreases first in the upper trunk. 
E)  In the evening, the diameter of a tree increases first in the lower trunk.

Question 19

The cuticle is largely impermeable to both water and carbon dioxide.

Accepted Answer

A) True 
 B)False

Question 20

A plant loses the greatest amount of water through the:

Accepted Answer

A)  leaf cuticle. 
B)  stem cuticle. 
C)  root cuticle. 
D)  stomata. 
E)  lenticels. 
A)  leaf cuticle. 
B)  stem cuticle. 
C)  root cuticle. 
D)  stomata. 
E)  lenticels.

Exam 30: The Movement of Water and Solutes in Plants

In the process of guttation, water is exuded from leaves through hydathodes.

Which of the following is/are present in the highest concentration in sieve-tube sap?

It is the smallest pores in the walls or pit membranes of vessels or tracheids that are the most susceptible to air seeding.

Which of the following is NOT evidence supporting the role of phloem in sugar transport?

In the process of stomatal movement, blue light activates a proton pump in the plasma membrane of the guard cell.

Which of the following statements about sources and sinks in assimilate movement is FALSE?

Radial micellation refers to the ______ of guard cells.

In the process of stomatal closing, which of the following events occurs first?

Phototropins are:

The driving force for assimilate transport is:

Mycorrhizae are especially important in the plant's absorption of:

Which of the following statements about stomatal movements is FALSE?

A dry breeze increases the rate of transpiration mainly because it:

The polymer trapping mechanism is a symplastic loading mechanism.

Nocturnal transpiration occurs in CAM plants but not C3 plants.

In vascular plants, hydraulic redistribution is the:

The transport of the assimilate stream in the phloem is called translocation.

Which of the following does NOT provide evidence supporting the cohesion-tension theory?

The cuticle is largely impermeable to both water and carbon dioxide.

A plant loses the greatest amount of water through the:

Botany: an Introduction

The Molecular Composition of Plant Cells

The Plant Cell and the Cell Cycle

The Movement of Substances Into and Out of Cells

The Flow of Energy

Respiration

Photosynthesis, Light, and Life

Sexual Reproduction and Heredity

The Chemistry of Heredity and Gene Expression

Recombinant Dna Technology, Plant Biotechnology, and Genomics

The Process of Evolution

Systematics: the Science of Biological Diversity

Prokaryotes and Viruses

Fungi

Protists: Algae and Heterotrophic Protists

Bryophytes

Seedless Vascular Plants

Gymnosperms

Introduction to the Angiosperms

Evolution of the Angiosperms

Plants and People

Early Development of the Plant Body

Cells and Tissues of the Plant Body

The Root: Structure and Development

The Shoot: Primary Structure and Development

Secondary Growth in Stems

Regulating Growth and Development: the Plant Hormones

External Factors and Plant Growth

Plant Nutrition and Soils

The Dynamics of Communities and Ecosystems

Global Ecology

Filters

Nocturnal transpiration occurs in CAM plants but not C₃ plants.