Question 1

Why is nitrogen fixation an essential process?

Accepted Answer

A)  Nitrogen fixation can only be done by certain prokaryotes. 
B)  Fixed nitrogen is often the limiting factor in plant growth. 
C)  Nitrogen fixation is very expensive in terms of metabolic energy. 
D)  Nitrogen fixers are sometimes symbiotic with legumes. 
A)  Nitrogen fixation can only be done by certain prokaryotes. 
B)  Fixed nitrogen is often the limiting factor in plant growth. 
C)  Nitrogen fixation is very expensive in terms of metabolic energy. 
D)  Nitrogen fixers are sometimes symbiotic with legumes. B

Question 2

The earliest vascular plants on land had underground stems (rhizomes) but no roots. Water and mineral nutrients were most likely obtained by

Accepted Answer

A)  absorption by hairs and trichomes. 
B)  absorption by mycorrhizae. 
C)  osmosis through the root hairs. 
D)  diffusion across the cuticle of the rhizome. 
A)  absorption by hairs and trichomes. 
B)  absorption by mycorrhizae. 
C)  osmosis through the root hairs. 
D)  diffusion across the cuticle of the rhizome. B

Question 3

Which of the following is of least concern to a researcher in a mineral nutrition experiment?

Accepted Answer

A)  purity of the chemicals used to make the nutrient solutions 
B)  purity of the water used to make the nutrient solutions 
C)  ability of a laboratory balance to weigh very small quantities of chemicals 
D)  medium in which the test seedlings were grown 
A)  purity of the chemicals used to make the nutrient solutions 
B)  purity of the water used to make the nutrient solutions 
C)  ability of a laboratory balance to weigh very small quantities of chemicals 
D)  medium in which the test seedlings were grown C

Question 4

Compared to a cell with few aquaporins in its membrane, a cell containing many aquaporins will

Accepted Answer

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

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

Question 6

In hydroponic culture, what is the purpose of bubbling air into the solute?

Accepted Answer

A)  to keep dissolved nutrients evenly distributed 
B)  to provide oxygen to the root cells 
C)  to inhibit the growth of aerobic algae 
D)  to inhibit the growth of anaerobic bacteria 
A)  to keep dissolved nutrients evenly distributed 
B)  to provide oxygen to the root cells 
C)  to inhibit the growth of aerobic algae 
D)  to inhibit the growth of anaerobic bacteria

Question 7

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. 
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.

Question 8

Which of the following would be least likely to affect osmosis in plants?

Accepted Answer

A)  proton pumps in the membrane 
B)  a difference in solute concentrations 
C)  receptor proteins in the membrane 
D)  aquaporins 
A)  proton pumps in the membrane 
B)  a difference in solute concentrations 
C)  receptor proteins in the membrane 
D)  aquaporins

Question 9

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. 
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.

Question 10

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 
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

Question 11

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

Question 12

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. 
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.

Question 13

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

Question 14

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. 
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.

Question 15

Rhizobia, actinomycetes, and cyanobacteria all share the common feature that they can

Accepted Answer

A)  increase water uptake in plants. 
B)  increase nutrient availability in the soil for plants. 
C)  kill parasites in the soil. 
D)  fix atmospheric nitrogen. 
A)  increase water uptake in plants. 
B)  increase nutrient availability in the soil for plants. 
C)  kill parasites in the soil. 
D)  fix atmospheric nitrogen.

Question 16

Water potential is generally most negative in which of the following parts of a plant?

Accepted Answer

A)  mesophyll cells of the leaf 
B)  xylem vessels in leaves 
C)  xylem vessels in roots 
D)  cells of the root cortex 
A)  mesophyll cells of the leaf 
B)  xylem vessels in leaves 
C)  xylem vessels in roots 
D)  cells of the root cortex

Question 17

You are conducting an experiment on plant growth. You take a plant fresh from the soil that weighs 5 kg. Then you dry the plant overnight and determine the dry weight to be 1 kg. Of this dry weight, how much would you expect to be made up of organic molecules?

Accepted Answer

A)  1 g 
B)  4 g 
C)  40 g 
D)  960 g 
A)  1 g 
B)  4 g 
C)  40 g 
D)  960 g

Question 18

Why does overwatering a plant kill it?

Accepted Answer

A)  Water does not have all the necessary minerals a plant needs to grow. 
B)  Water neutralizes the pH of the soil. 
C)  The roots are deprived of oxygen. 
D)  Water supports the growth of root parasites. 
A)  Water does not have all the necessary minerals a plant needs to grow. 
B)  Water neutralizes the pH of the soil. 
C)  The roots are deprived of oxygen. 
D)  Water supports the growth of root parasites.

Question 19

The NPK percentages on a package of fertilizer refer to the

Accepted Answer

A)  total protein content of the three major ingredients of the fertilizer. 
B)  percentages of manure collected from different types of animals. 
C)  relative percentages of organic and inorganic nutrients in the fertilizer. 
D)  percentages of three important mineral nutrients. 
A)  total protein content of the three major ingredients of the fertilizer. 
B)  percentages of manure collected from different types of animals. 
C)  relative percentages of organic and inorganic nutrients in the fertilizer. 
D)  percentages of three important mineral nutrients.

Question 20

Plants do not have a circulatory system like that of some animals. If a water molecule did "circulate" (that is, go from one point in a plant to another and back in the same day), it would require the activity of

Accepted Answer

A)  only the xylem. 
B)  only the phloem. 
C)  only the endodermis. 
D)  both the xylem and the phloem. 
A)  only the xylem. 
B)  only the phloem. 
C)  only the endodermis. 
D)  both the xylem and the phloem.

Exam 29: Resource Acquisition, Nutrition, and Transport in Vascular Plants

Why is nitrogen fixation an essential process?

The earliest vascular plants on land had underground stems (rhizomes) but no roots. Water and mineral nutrients were most likely obtained by

Which of the following is of least concern to a researcher in a mineral nutrition experiment?

Compared to a cell with few aquaporins in its membrane, a cell containing many aquaporins will

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

In hydroponic culture, what is the purpose of bubbling air into the solute?

Root hairs are most important to a plant because they

Which of the following would be least likely to affect osmosis in plants?

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

Which structure or compartment is part of the symplast?

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?

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

Photosynthesis begins to decline when leaves wilt because

Rhizobia, actinomycetes, and cyanobacteria all share the common feature that they can

Water potential is generally most negative in which of the following parts of a plant?

You are conducting an experiment on plant growth. You take a plant fresh from the soil that weighs 5 kg. Then you dry the plant overnight and determine the dry weight to be 1 kg. Of this dry weight, how much would you expect to be made up of organic molecules?

Why does overwatering a plant kill it?

The NPK percentages on a package of fertilizer refer to the

Plants do not have a circulatory system like that of some animals. If a water molecule did "circulate" (that is, go from one point in a plant to another and back in the same day), it would require the activity of

Introduction: Evolution and the Foundations of Biology

The Chemical Context of Life

Carbon and the Molecular Diversity of Life

A Tour of the Cell

Membrane Transport and Cell Signaling

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Development, Stem Cells, and Cancer

Viruses

Genomes and Their Evolution

Descent With Modification

Phylogeny

The Evolution of Populations

The Origin of Species

Broad Patterns of Evolution

Early Life and the Diversification of Prokaryotes

The Origin and Diversification of Eukaryotes

The Colonization of Land by Plants and Fungi

The Rise of Animal Diversity

Plant Structure and Growth

Reproduction and Domestication of Flowering Plants

Plant Responses to Internal and External Signals

Homeostasis and Endocrine Signaling

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Reproduction and Development

Neurons, Synapses, and Signaling

Nervous and Sensory Systems

Motor Mechanisms and Behavior

Population Ecology and the Distribution of Organisms

Species Interactions

Ecosystems and Energy

Global Ecology and Conservation Biology

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