Question 1

The ________ is responsible for the transport of sucrose to companion cells and sieve tube elements.

Accepted Answer

A) chemiosmotic mechanism 
B) apoplastic pathway 
C) symplastic pathway 
D) passive transport 
E) potassium pump 
A) chemiosmotic mechanism 
B) apoplastic pathway 
C) symplastic pathway 
D) passive transport 
E) potassium pump

Question 2

Which of the following statements about transport in plants is false?

Accepted Answer

A) Weak bonding between water molecules and the walls of xylem vessels or tracheids helps support the columns of water in the xylem. 
B) Hydrogen bonding between water molecules, which results in the high cohesion of the water, is essential for the rise of water in tall trees. 
C) Although some angiosperm plants develop considerable root pressure, this is not sufficient to raise water to the tops of tall trees. 
D) Most plant physiologists now agree that the pull from the top of the plant resulting from transpiration is sufficient, when combined with the cohesion of water, to explain the rise of water in the xylem in even the tallest trees. 
E) Gymnosperms can sometimes develop especially high root pressure, which may account for the rise of water in tall pine trees without transpiration pull. 
A) Weak bonding between water molecules and the walls of xylem vessels or tracheids helps support the columns of water in the xylem. 
B) Hydrogen bonding between water molecules, which results in the high cohesion of the water, is essential for the rise of water in tall trees. 
C) Although some angiosperm plants develop considerable root pressure, this is not sufficient to raise water to the tops of tall trees. 
D) Most plant physiologists now agree that the pull from the top of the plant resulting from transpiration is sufficient, when combined with the cohesion of water, to explain the rise of water in the xylem in even the tallest trees. 
E) Gymnosperms can sometimes develop especially high root pressure, which may account for the rise of water in tall pine trees without transpiration pull.

Question 3

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 4

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 5

The symplast transports all of the following except

Accepted Answer

A) sugars. 
B) mRNA. 
C) DNA. 
D) proteins. 
E) viruses. 
A) sugars. 
B) mRNA. 
C) DNA. 
D) proteins. 
E) viruses.

Question 6

Which of the following statements is false concerning the xylem?

Accepted Answer

A) Xylem tracheids and vessels fulfill their vital function only after their death. 
B) The cell walls of the tracheids are greatly strengthened with cellulose fibrils forming thickened rings or spirals. 
C) Water molecules are transpired from the cells of the leaves, and replaced by water molecules in the xylem pulled up from the roots due to the cohesion of water molecules. 
D) Movement of materials is by mass flow; solutes in xylary sap move due to a positive turgor pressure gradient from source to sink. 
E) In the morning, sap in the xylem begins to move first in the twigs of the upper portion of the tree, and later in the lower trunk. 
A) Xylem tracheids and vessels fulfill their vital function only after their death. 
B) The cell walls of the tracheids are greatly strengthened with cellulose fibrils forming thickened rings or spirals. 
C) Water molecules are transpired from the cells of the leaves, and replaced by water molecules in the xylem pulled up from the roots due to the cohesion of water molecules. 
D) Movement of materials is by mass flow; solutes in xylary sap move due to a positive turgor pressure gradient from source to sink. 
E) In the morning, sap in the xylem begins to move first in the twigs of the upper portion of the tree, and later in the lower trunk.

Question 7

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 8

According to the pressure flow hypothesis of phloem transport

Accepted Answer

A) solute moves from a high concentration in the source to a lower concentration in the sink. 
B) water is actively transported into the source region of the phloem to create the turgor pressure needed. 
C) the combination of a high turgor pressure in the source and transpiration water loss from the sink moves solutes through phloem conduits. 
D) the formation of starch from sugar in the sink increases the osmotic concentration. 
E) the pressure in the phloem of a root is normally greater than the pressure in the phloem of a leaf. 
A) solute moves from a high concentration in the source to a lower concentration in the sink. 
B) water is actively transported into the source region of the phloem to create the turgor pressure needed. 
C) the combination of a high turgor pressure in the source and transpiration water loss from the sink moves solutes through phloem conduits. 
D) the formation of starch from sugar in the sink increases the osmotic concentration. 
E) the pressure in the phloem of a root is normally greater than the pressure in the phloem of a leaf.

Question 9

If a mutation occurred and Casparian strips were not produced in root endodermal cells, what would happen to the plant?

Accepted Answer

A) Water movement depends on transpiration; the plant would keep photosynthesizing and growing. 
B) The plant would not be able to regulate uptake of water and ions into the rest of the plant and the plant would not grow. 
C) Water and ions would have to move via an alternative pathway. 
D) Entry of water and ions would occur via root hairs and the plant would continue to grow. 
A) Water movement depends on transpiration; the plant would keep photosynthesizing and growing. 
B) The plant would not be able to regulate uptake of water and ions into the rest of the plant and the plant would not grow. 
C) Water and ions would have to move via an alternative pathway. 
D) Entry of water and ions would occur via root hairs and the plant would continue to grow.

Question 10

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 11

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 12

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 13

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 14

Movement of phloem sap from a source to a sink

Accepted Answer

A) occurs through the apoplast of sieve-tube elements. 
B) depends ultimately on the activity of proton pumps. 
C) depends on tension, or negative pressure potential. 
D) depends on pumping water into sieve tubes at the source. 
E) results mainly from diffusion. 
A) occurs through the apoplast of sieve-tube elements. 
B) depends ultimately on the activity of proton pumps. 
C) depends on tension, or negative pressure potential. 
D) depends on pumping water into sieve tubes at the source. 
E) results mainly from diffusion.

Question 15

A water molecule could move all the way through a plant from soil to root to leaf to air and pass through a living cell only once. This living cell would be a part of which structure?

Accepted Answer

A) the Casparian strip 
B) a guard cell 
C) the root epidermis 
D) the endodermis 
E) the root cortex 
A) the Casparian strip 
B) a guard cell 
C) the root epidermis 
D) the endodermis 
E) the root cortex

Question 16

Root hairs are most important to a plant because they

Accepted Answer

A) anchor a plant in the soil. 
B) store starches. 
C) increase the surface area for absorption. 
D) provide a habitat for nitrogen-fixing bacteria. 
E) contain xylem tissue. 
A) anchor a plant in the soil. 
B) store starches. 
C) increase the surface area for absorption. 
D) provide a habitat for nitrogen-fixing bacteria. 
E) contain xylem tissue.

Question 17

Which of the following best explains why very few CAM plants are tall?

Accepted Answer

A) They have difficulty moving water and minerals to the top of the plant during the day. 
B) They would be unable to supply sufficient sucrose for active transport of minerals into the roots during the day or night. 
C) Transpiration occurs only at night, and this would cause a highly negative Ψ in the roots of a tall plant during the day. 
D) Since the stomata are closed in the leaves, the Casparian strip is closed in the endodermis of the root. 
E) With the stomata open at night, the transpiration rate would limit plant height. 
A) They have difficulty moving water and minerals to the top of the plant during the day. 
B) They would be unable to supply sufficient sucrose for active transport of minerals into the roots during the day or night. 
C) Transpiration occurs only at night, and this would cause a highly negative Ψ in the roots of a tall plant during the day. 
D) Since the stomata are closed in the leaves, the Casparian strip is closed in the endodermis of the root. 
E) With the stomata open at night, the transpiration rate would limit plant height.

Question 18

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 19

A primary result for stomatal closure on a hot, dry day would be

Accepted Answer

A) release of K⁺ ions to the apoplast and subsidiary cells. 
B) displacement of Ca⁺⁺ ions from the thick inner walls of the guard cells. 
C) disassembly of the microfibrils in the cell walls of the subsidiary cells. 
D) upregulation of aquaporin synthesis. 
E) downregulation of extension proteins. 
A) release of K⁺ ions to the apoplast and subsidiary cells. 
B) displacement of Ca⁺⁺ ions from the thick inner walls of the guard cells. 
C) disassembly of the microfibrils in the cell walls of the subsidiary cells. 
D) upregulation of aquaporin synthesis. 
E) downregulation of extension proteins.

Question 20

All of the following are plant adaptations to life on land except

Accepted Answer

A) tracheids and vessels. 
B) root hairs. 
C) cuticle. 
D) the Calvin cycle of photosynthesis. 
E) collenchyma. 
A) tracheids and vessels. 
B) root hairs. 
C) cuticle. 
D) the Calvin cycle of photosynthesis. 
E) collenchyma.

Exam 36: Resource Acquisition and Transport in Vascular Plants

The ________ is responsible for the transport of sucrose to companion cells and sieve tube elements.

Which of the following statements about transport in plants is false?

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

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

The symplast transports all of the following except

Which of the following statements is false concerning the xylem?

Which of the following statements is false about bulk flow?

According to the pressure flow hypothesis of phloem transport

If a mutation occurred and Casparian strips were not produced in root endodermal cells, what would happen to the plant?

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?

Guard cells do which of the following?

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

Movement of phloem sap from a source to a sink

A water molecule could move all the way through a plant from soil to root to leaf to air and pass through a living cell only once. This living cell would be a part of which structure?

Root hairs are most important to a plant because they

Which of the following best explains why very few CAM plants are tall?

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

A primary result for stomatal closure on a hot, dry day would be

All of the following are plant adaptations to life on land except

Introduction: Evolution and Themes of Biology

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

Dna Tools and 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 Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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