Question 1

Photosynthesis begins to decline when leaves wilt because

Accepted Answer

A)  chloroplasts within wilted leaves are incapable of photosynthesis. 
B)  CO₂ accumulates in the leaves and inhibits the enzymes needed for photosynthesis. 
C)  there is insufficient water for photolysis during the light reactions. 
D)  stomata close, restricting CO₂ entry into the leaf. 
E)  wilted leaves cannot absorb the red and blue wavelengths of light. 
A)  chloroplasts within wilted leaves are incapable of photosynthesis. 
B)  CO₂ accumulates in the leaves and inhibits the enzymes needed for photosynthesis. 
C)  there is insufficient water for photolysis during the light reactions. 
D)  stomata close, restricting CO₂ entry into the leaf. 
E)  wilted leaves cannot absorb the red and blue wavelengths of light.

Question 2

Arrange the following five events in an order that explains the mass flow of materials in the phloem.
1)Water diffuses into the sieve tubes.
2)Leaf cells produce sugar by photosynthesis.
3)Solutes are actively transported into sieve tubes.
4)Sugar is transported from cell to cell in the leaf.
5)Sugar moves down the stem.

Accepted Answer

A)  2, 1, 4, 3, 5 
B)  1, 2, 3, 4, 5 
C)  2, 4, 3, 1, 5 
D)  4, 2, 1, 3, 5 
E)  2, 4, 1, 3, 5 
A)  2, 1, 4, 3, 5 
B)  1, 2, 3, 4, 5 
C)  2, 4, 3, 1, 5 
D)  4, 2, 1, 3, 5 
E)  2, 4, 1, 3, 5

Question 3

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 10 square meters. Where is the most likely environment where this leaf was growing?

Accepted Answer

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

Question 4

The opening of stomata is thought to involve

Accepted Answer

A)  an increase in the solute concentration of the guard cells. 
B)  a decrease in the solute concentration of the stoma. 
C)  active transport of water out of the guard cells. 
D)  decreased turgor pressure in guard cells. 
E)  movement of K⁺ from the guard cells. 
A)  an increase in the solute concentration of the guard cells. 
B)  a decrease in the solute concentration of the stoma. 
C)  active transport of water out of the guard cells. 
D)  decreased turgor pressure in guard cells. 
E)  movement of K⁺ from the guard cells.

Question 5

Which of the following has the lowest (most negative)water potential?

Accepted Answer

A)  root cortical cells 
B)  root xylem 
C)  trunk xylem 
D)  leaf cell walls 
E)  leaf air spaces 
A)  root cortical cells 
B)  root xylem 
C)  trunk xylem 
D)  leaf cell walls 
E)  leaf air spaces

Question 6

Which structure or compartment is part of the symplast?

Accepted Answer

A)  the interior of a vessel element 
B)  the interior of a sieve tube 
C)  the cell wall of a mesophyll cell 
D)  an extracellular air space 
E)  the cell wall of a root hair 
A)  the interior of a vessel element 
B)  the interior of a sieve tube 
C)  the cell wall of a mesophyll cell 
D)  an extracellular air space 
E)  the cell wall of a root hair

Question 7

Ignoring all other factors, what kind of day would result in the fastest delivery of water and minerals to the leaves of a tree?

Accepted Answer

A)  cool, dry day 
B)  warm, dry day 
C)  warm, humid day 
D)  cool, humid day 
E)  very hot, dry, windy day 
A)  cool, dry day 
B)  warm, dry day 
C)  warm, humid day 
D)  cool, humid day 
E)  very hot, dry, windy day

Question 8

Which of the following is responsible for the cohesion of water molecules?

Accepted Answer

A)  hydrogen bonds between the oxygen atoms of a water molecule and cellulose in a vessel cell 
B)  covalent bonds between the hydrogen atoms of two adjacent water molecules 
C)  hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule 
D)  covalent bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule 
E)  low concentrations of charged solutes in the fluid 
A)  hydrogen bonds between the oxygen atoms of a water molecule and cellulose in a vessel cell 
B)  covalent bonds between the hydrogen atoms of two adjacent water molecules 
C)  hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule 
D)  covalent bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule 
E)  low concentrations of charged solutes in the fluid

Question 9

Guard cells do which of the following?

Accepted Answer

A)  protect the endodermis 
B)  accumulate K⁺ and close the stomata 
C)  contain chloroplasts that import K⁺ directly into the cells 
D)  guard against mineral loss through the stomata 
E)  help balance the photosynthesis-transpiration compromise 
A)  protect the endodermis 
B)  accumulate K⁺ and close the stomata 
C)  contain chloroplasts that import K⁺ directly into the cells 
D)  guard against mineral loss through the stomata 
E)  help balance the photosynthesis-transpiration compromise

Question 10

Which of the following statements is false about bulk flow?

Accepted Answer

A)  It is driven primarily by pressure potential. 
B)  It is more effective than diffusion over distances greater than 100 μm. 
C)  It depends on a difference in pressure potential at the source and sink. 
D)  It depends on the force of gravity on a column of water. 
E)  It may be the result of either positive or negative pressure potential. 
A)  It is driven primarily by pressure potential. 
B)  It is more effective than diffusion over distances greater than 100 μm. 
C)  It depends on a difference in pressure potential at the source and sink. 
D)  It depends on the force of gravity on a column of water. 
E)  It may be the result of either positive or negative pressure potential.

Question 11

What would enhance water uptake by a plant cell?

Accepted Answer

A)  decreasing the Ψ of the surrounding solution 
B)  increasing the pressure exerted by the cell wall 
C)  the loss of solutes from the cell 
D)  increasing the Ψ of the cytoplasm 
E)  positive pressure on the surrounding solution 
A)  decreasing the Ψ of the surrounding solution 
B)  increasing the pressure exerted by the cell wall 
C)  the loss of solutes from the cell 
D)  increasing the Ψ of the cytoplasm 
E)  positive pressure on the surrounding solution

Question 12

In plant roots, the Casparian strip is correctly described by which of the following?

Accepted Answer

A)  It aids in the uptake of nutrients. 
B)  It provides energy for the active transport of minerals into the stele from the cortex. 
C)  It ensures that all minerals are absorbed from the soil in equal amounts. 
D)  It ensures that all water and dissolved substances must pass through a cell membrane before entering the stele. 
E)  It provides increased surface area for the absorption of mineral nutrients. 
A)  It aids in the uptake of nutrients. 
B)  It provides energy for the active transport of minerals into the stele from the cortex. 
C)  It ensures that all minerals are absorbed from the soil in equal amounts. 
D)  It ensures that all water and dissolved substances must pass through a cell membrane before entering the stele. 
E)  It provides increased surface area for the absorption of mineral nutrients.

Question 13

Which of the following statements about xylem is incorrect?

Accepted Answer

A)  It conducts material from root tips to leaves. 
B)  The conducting cells are part of the apoplast. 
C)  It transports mainly sugars and amino acids. 
D)  It typically has a lower water potential than is found in soil. 
E)  No energy input is required for transport. 
A)  It conducts material from root tips to leaves. 
B)  The conducting cells are part of the apoplast. 
C)  It transports mainly sugars and amino acids. 
D)  It typically has a lower water potential than is found in soil. 
E)  No energy input is required for transport.

Question 14

Transpiration in plants requires all of the following except

Accepted Answer

A)  adhesion of water molecules to cellulose. 
B)  cohesion between water molecules. 
C)  evaporation of water molecules. 
D)  active transport through xylem cells. 
E)  transport through tracheids. 
A)  adhesion of water molecules to cellulose. 
B)  cohesion between water molecules. 
C)  evaporation of water molecules. 
D)  active transport through xylem cells. 
E)  transport through tracheids.

Question 15

In which plant cell or tissue would the pressure component of water potential most often be negative?

Accepted Answer

A)  leaf mesophyll cell 
B)  stem xylem 
C)  stem phloem 
D)  root cortex cell 
E)  root epidermis 
A)  leaf mesophyll cell 
B)  stem xylem 
C)  stem phloem 
D)  root cortex cell 
E)  root epidermis

Question 16

All of the following have an effect on water potential (Ψ)in plants except

Accepted Answer

A)  physical pressure. 
B)  water-attracting matrices. 
C)  dissolved solutes. 
D)  osmosis. 
E)  DNA structure. 
A)  physical pressure. 
B)  water-attracting matrices. 
C)  dissolved solutes. 
D)  osmosis. 
E)  DNA structure.

Question 17

One would expect to find the highest density of aquaporins in which of the following?

Accepted Answer

A)  the plasma membrane of guard cells 
B)  the pits of a tracheid 
C)  the plasma membrane of parenchyma cells in a ripe fruit 
D)  the plasma membrane of a mature mesophyll cell in a leaf 
E)  the membrane lining plasmodesmata 
A)  the plasma membrane of guard cells 
B)  the pits of a tracheid 
C)  the plasma membrane of parenchyma cells in a ripe fruit 
D)  the plasma membrane of a mature mesophyll cell in a leaf 
E)  the membrane lining plasmodesmata

Question 18

An open beaker of pure water has a water potential (Ψ)of

Accepted Answer

A)  -0.23 MPa. 
B)  +0.23 MPa. 
C)  +0.07 MPa. 
D)  -0.0000001 MPa. 
E)  0.0 (zero). 
A)  -0.23 MPa. 
B)  +0.23 MPa. 
C)  +0.07 MPa. 
D)  -0.0000001 MPa. 
E)  0.0 (zero).

Question 19

Guard cells are the only cells in the epidermis that contain chloroplasts and can undergo photosynthesis. This is important because

Accepted Answer

A)  chloroplasts sense when light is available so that guard cells will open. 
B)  photosynthesis provides the energy necessary for contractile proteins to flex and open the guard cells. 
C)  guard cells will produce the O₂ necessary to power active transport. 
D)  ATP is required to power proton pumps in the guard cell membranes. 
E)  chloroplasts sense when light is available so that guard cells will open and guard cells will produce the O₂ necessary to power active transport. 
A)  chloroplasts sense when light is available so that guard cells will open. 
B)  photosynthesis provides the energy necessary for contractile proteins to flex and open the guard cells. 
C)  guard cells will produce the O₂ necessary to power active transport. 
D)  ATP is required to power proton pumps in the guard cell membranes. 
E)  chloroplasts sense when light is available so that guard cells will open and guard cells will produce the O₂ necessary to power active transport.

Question 20

All of the following involve active transport across membranes except

Accepted Answer

A)  the movement of mineral nutrients from the apoplast to the symplast. 
B)  the movement of sugar from mesophyll cells into sieve-tube elements. 
C)  the movement of sugar from one sieve-tube element to the next. 
D)  the movement of K⁺ across guard cell membranes during stomatal opening. 
E)  the movement of mineral nutrients into cells of the root cortex. 
A)  the movement of mineral nutrients from the apoplast to the symplast. 
B)  the movement of sugar from mesophyll cells into sieve-tube elements. 
C)  the movement of sugar from one sieve-tube element to the next. 
D)  the movement of K⁺ across guard cell membranes during stomatal opening. 
E)  the movement of mineral nutrients into cells of the root cortex.

Exam 36: Resource Acquisition and Transport in Vascular Plants

Photosynthesis begins to decline when leaves wilt because

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 10 square meters. Where is the most likely environment where this leaf was growing?

The opening of stomata is thought to involve

Which of the following has the lowest (most negative)water potential?

Which structure or compartment is part of the symplast?

Ignoring all other factors, what kind of day would result in the fastest delivery of water and minerals to the leaves of a tree?

Which of the following is responsible for the cohesion of water molecules?

Guard cells do which of the following?

Which of the following statements is false about bulk flow?

What would enhance water uptake by a plant cell?

In plant roots, the Casparian strip is correctly described by which of the following?

Which of the following statements about xylem is incorrect?

Transpiration in plants requires all of the following except

In which plant cell or tissue would the pressure component of water potential most often be negative?

All of the following have an effect on water potential (Ψ)in plants except

One would expect to find the highest density of aquaporins in which of the following?

An open beaker of pure water has a water potential (Ψ)of

Guard cells are the only cells in the epidermis that contain chloroplasts and can undergo photosynthesis. This is important because

All of the following involve active transport across membranes except

Introduction: Themes in the Study of Life

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Viruses

Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure, Growth, and Development

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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