Question 1

If the guard cells and surrounding epidermal cells in a plant are deficient in potassium ions, all of the following would occur except

Accepted Answer

A)  photosynthesis would decrease. 
B)  roots would take up less water. 
C)  phloem transport rates would decrease. 
D)  leaf temperatures would decrease. 
E)  stomata would be closed. 
A)  photosynthesis would decrease. 
B)  roots would take up less water. 
C)  phloem transport rates would decrease. 
D)  leaf temperatures would decrease. 
E)  stomata would be closed. D

Question 2

Plasmodesmata can change in number, and when dilated can provide a passageway for

Accepted Answer

A)  macromolecules such as RNA and proteins. 
B)  ribosomes. 
C)  chloroplasts. 
D)  mitochondria. 
E)  cytoskeletal components. 
A)  macromolecules such as RNA and proteins. 
B)  ribosomes. 
C)  chloroplasts. 
D)  mitochondria. 
E)  cytoskeletal components. A

Question 3

Phloem transport of sucrose is often described as going from source to sink. Which of the following would not normally function as a sink?

Accepted Answer

A)  growing leaf 
B)  growing root 
C)  storage organ in summer 
D)  mature leaf 
E)  shoot tip 
A)  growing leaf 
B)  growing root 
C)  storage organ in summer 
D)  mature leaf 
E)  shoot tip D

Question 4

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)  water potential in the stele of the root is high. 
E)  roots are not absorbing minerals from the soil. 
A)  transpiration rates are high. 
B)  root pressure exceeds transpiration pull. 
C)  preceding evening was hot, windy, and dry. 
D)  water potential in the stele of the root is high. 
E)  roots are not absorbing minerals from the soil.

Question 5

If you were to prune the shoot tips of a plant, what would be the effect on the plant and the leaf area index?

Accepted Answer

A)  bushier plants; lower leaf area index 
B)  tall plants; lower leaf area index 
C)  tall plants; higher leaf area index 
D)  short plants; lower leaf area index 
E)  bushier plants; higher leaf area indexes 
A)  bushier plants; lower leaf area index 
B)  tall plants; lower leaf area index 
C)  tall plants; higher leaf area index 
D)  short plants; lower leaf area index 
E)  bushier plants; higher leaf area indexes

Question 6

Which of the following experimental procedures would most likely reduce transpiration while allowing the normal growth of a plant?

Accepted Answer

A)  subjecting the leaves of the plant to a partial vacuum 
B)  increasing the level of carbon dioxide around the plant 
C)  putting the plant in drier soil 
D)  decreasing the relative humidity around the plant 
E)  injecting potassium ions into the guard cells of the plant 
A)  subjecting the leaves of the plant to a partial vacuum 
B)  increasing the level of carbon dioxide around the plant 
C)  putting the plant in drier soil 
D)  decreasing the relative humidity around the plant 
E)  injecting potassium ions into the guard cells of the plant

Question 7

Water rises in plants primarily by cohesion-tension. Which of the following is not true about the cohesion-tension model?

Accepted Answer

A)  Water loss (transpiration) is the driving force for water movement. 
B)  The "tension" of this model represents the excitability of the xylem cells. 
C)  Cohesion represents the tendency for water molecules to stick together by hydrogen bonds. 
D)  The physical forces in the capillary-sized xylem cells make it easier to overcome gravity. 
E)  The water potential of the air is more negative than the xylem. 
A)  Water loss (transpiration) is the driving force for water movement. 
B)  The "tension" of this model represents the excitability of the xylem cells. 
C)  Cohesion represents the tendency for water molecules to stick together by hydrogen bonds. 
D)  The physical forces in the capillary-sized xylem cells make it easier to overcome gravity. 
E)  The water potential of the air is more negative than the xylem.

Question 8

The ancestors of land plants were aquatic algae. Which of the following is not an evolutionary adaptation to life on land?

Accepted Answer

A)  C₃ photosynthesis 
B)  a waxy cuticle 
C)  root hairs 
D)  xylem and phloem 
E)  guard cells 
A)  C₃ photosynthesis 
B)  a waxy cuticle 
C)  root hairs 
D)  xylem and phloem 
E)  guard cells

Question 9

A plant developed a mineral deficiency after being treated with a fungicide. What is the most probable cause of the deficiency?

Accepted Answer

A)  Mineral receptor proteins in the plant membrane were not functioning. 
B)  Mycorrhizal fungi were killed. 
C)  Active transport of minerals was inhibited. 
D)  The genes for the synthesis of transport proteins were destroyed. 
E)  Proton pumps reversed the membrane potential. 
A)  Mineral receptor proteins in the plant membrane were not functioning. 
B)  Mycorrhizal fungi were killed. 
C)  Active transport of minerals was inhibited. 
D)  The genes for the synthesis of transport proteins were destroyed. 
E)  Proton pumps reversed the membrane potential.

Question 10

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 above the shallow fresh water in which they lived. 
B)  species that did not exhibit alternation of generations. 
C)  vascular plants with well-defined root systems. 
D)  plants with well-developed leaves. 
E)  species with a well-developed, thick cuticle. 
A)  nonvascular plants that grew leafless photosynthetic shoots above the shallow fresh water in which they lived. 
B)  species that did not exhibit alternation of generations. 
C)  vascular plants with well-defined root systems. 
D)  plants with well-developed leaves. 
E)  species with a well-developed, thick cuticle.

Question 11

What is the driving force for the movement of solutes in the phloem of plants?

Accepted Answer

A)  gravity 
B)  a difference in water potential (Ψ) between the source and the sink 
C)  root pressure 
D)  transpiration of water through the stomata 
E)  adhesion of water to phloem sieve tubes 
A)  gravity 
B)  a difference in water potential (Ψ) between the source and the sink 
C)  root pressure 
D)  transpiration of water through the stomata 
E)  adhesion of water to phloem sieve tubes

Question 12

Which of the following is a correct statement about sugar movement in phloem?

Accepted Answer

A)  Diffusion can account for the observed rates of transport. 
B)  Movement can occur both upward and downward in the plant. 
C)  Sugar is translocated from sinks to sources. 
D)  Only phloem cells with nuclei can perform sugar movement. 
E)  Sugar transport does not require energy. 
A)  Diffusion can account for the observed rates of transport. 
B)  Movement can occur both upward and downward in the plant. 
C)  Sugar is translocated from sinks to sources. 
D)  Only phloem cells with nuclei can perform sugar movement. 
E)  Sugar transport does not require energy.

Question 13

Long-distance electrical signaling in the phloem has been shown to elicit a change in all of the following except

Accepted Answer

A)  rapid leaf movement. 
B)  gene transcription 
C)  a switch from C₄ to C₃ photosynthesis. 
D)  gene transcription. 
E)  phloem unloading. 
A)  rapid leaf movement. 
B)  gene transcription 
C)  a switch from C₄ to C₃ photosynthesis. 
D)  gene transcription. 
E)  phloem unloading.

Question 14

The movement of water across biological membranes can best be predicted by

Accepted Answer

A)  negative charges in the cell wall. 
B)  prevailing weather conditions. 
C)  aquaporins. 
D)  level of active transport. 
E)  water potential. 
A)  negative charges in the cell wall. 
B)  prevailing weather conditions. 
C)  aquaporins. 
D)  level of active transport. 
E)  water potential.

Question 15

Several tomato plants are growing in a small garden plot. If soil water potential were to drop significantly on a hot summer afternoon, which of the following would most likely occur?

Accepted Answer

A)  Stomatal apertures would decrease. 
B)  Transpiration would increase. 
C)  The leaves would become more turgid. 
D)  The uptake of CO₂ would be enhanced. 
E)  The proton gradient would dissipate. 
A)  Stomatal apertures would decrease. 
B)  Transpiration would increase. 
C)  The leaves would become more turgid. 
D)  The uptake of CO₂ would be enhanced. 
E)  The proton gradient would dissipate.

Question 16

Which of the following would likely not contribute to the surface area available for water absorption from the soil by a plant root system?

Accepted Answer

A)  root hairs 
B)  endodermis 
C)  mycorrhizae 
D)  fungi associated with the roots 
E)  fibrous arrangement of the roots 
A)  root hairs 
B)  endodermis 
C)  mycorrhizae 
D)  fungi associated with the roots 
E)  fibrous arrangement of the roots

Question 17

What is the role of proton pumps in root hair cells?

Accepted Answer

A)  establish ATP gradients 
B)  maintain the H⁺ gradient 
C)  pressurize xylem transport 
D)  eliminate excess electrons 
E)  assist in active uptake of water molecules 
A)  establish ATP gradients 
B)  maintain the H⁺ gradient 
C)  pressurize xylem transport 
D)  eliminate excess electrons 
E)  assist in active uptake of water molecules

Question 18

The value for Ψ in root tissue was found to be -0.15 MPa. If you take the root tissue and place it in a 0.1 M solution of sucrose (Ψ = -0.23 MPa), the net water flow would

Accepted Answer

A)  be from the tissue into the sucrose solution. 
B)  be from the sucrose solution into the tissue. 
C)  be in both directions and the concentrations would remain equal. 
D)  occur only as ATP was hydrolyzed in the tissue. 
E)  be impossible to determine from the values given here. 
A)  be from the tissue into the sucrose solution. 
B)  be from the sucrose solution into the tissue. 
C)  be in both directions and the concentrations would remain equal. 
D)  occur only as ATP was hydrolyzed in the tissue. 
E)  be impossible to determine from the values given here.

Question 19

All of the following are adaptations that help reduce water loss from a plant except

Accepted Answer

A)  transpiration. 
B)  sunken stomata. 
C)  C₄ photosynthesis. 
D)  small, thick leaves. 
E)  crassulacean acid metabolism. 
A)  transpiration. 
B)  sunken stomata. 
C)  C₄ photosynthesis. 
D)  small, thick leaves. 
E)  crassulacean acid metabolism.

Question 20

The following factors may sometimes play a role in the movement of sap through xylem. Which one depends on the direct expenditure of ATP by the plant?

Accepted Answer

A)  capillarity of water within the xylem 
B)  evaporation of water from leaves 
C)  cohesion among water molecules 
D)  concentration of ions in the symplast 
E)  bulk flow of water in the root apoplast 
A)  capillarity of water within the xylem 
B)  evaporation of water from leaves 
C)  cohesion among water molecules 
D)  concentration of ions in the symplast 
E)  bulk flow of water in the root apoplast

Exam 36: Resource Acquisition and Transport in Vascular Plants

If the guard cells and surrounding epidermal cells in a plant are deficient in potassium ions, all of the following would occur except

Plasmodesmata can change in number, and when dilated can provide a passageway for

Phloem transport of sucrose is often described as going from source to sink. Which of the following would not normally function as a sink?

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

If you were to prune the shoot tips of a plant, what would be the effect on the plant and the leaf area index?

Which of the following experimental procedures would most likely reduce transpiration while allowing the normal growth of a plant?

Water rises in plants primarily by cohesion-tension. Which of the following is not true about the cohesion-tension model?

The ancestors of land plants were aquatic algae. Which of the following is not an evolutionary adaptation to life on land?

A plant developed a mineral deficiency after being treated with a fungicide. What is the most probable cause of the deficiency?

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

What is the driving force for the movement of solutes in the phloem of plants?

Which of the following is a correct statement about sugar movement in phloem?

Long-distance electrical signaling in the phloem has been shown to elicit a change in all of the following except

The movement of water across biological membranes can best be predicted by

Several tomato plants are growing in a small garden plot. If soil water potential were to drop significantly on a hot summer afternoon, which of the following would most likely occur?

Which of the following would likely not contribute to the surface area available for water absorption from the soil by a plant root system?

What is the role of proton pumps in root hair cells?

The value for Ψ in root tissue was found to be -0.15 MPa. If you take the root tissue and place it in a 0.1 M solution of sucrose (Ψ = -0.23 MPa), the net water flow would

All of the following are adaptations that help reduce water loss from a plant except

The following factors may sometimes play a role in the movement of sap through xylem. Which one depends on the direct expenditure of ATP by the plant?

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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