Question 1

Which of the following are examples or parts of plants' systemic acquired resistance against infection?

Accepted Answer

A) phytoalexins 
B) salicylic acid 
C) alarm hormones 
D) A and B only 
E) A, B, and C 
A) phytoalexins 
B) salicylic acid 
C) alarm hormones 
D) A and B only 
E) A, B, and C

Question 2

Plant hormonal control differs from animal hormonal control in that there are no separate hormone producing organs in plants as there are in animals.

Accepted Answer

A) True 
 B)False

Question 3

A short-day plant will flower only when

Accepted Answer

A) days are shorter than nights. 
B) days are shorter than a certain critical value. 
C) nights are shorter than a certain critical value. 
D) nights are longer than a certain critical value. 
E) days and nights are of equal length. 
A) days are shorter than nights. 
B) days are shorter than a certain critical value. 
C) nights are shorter than a certain critical value. 
D) nights are longer than a certain critical value. 
E) days and nights are of equal length.

Question 4

Which of the following hormones would be most useful in promoting the rooting of plant cuttings?

Accepted Answer

A) oligosaccharins 
B) abscisic acid 
C) cytokinins 
D) gibberellins 
E) auxins 
A) oligosaccharins 
B) abscisic acid 
C) cytokinins 
D) gibberellins 
E) auxins

Question 5

Negative gravitropism of plant shoots

Accepted Answer

A) depends upon auxin distribution. 
B) depends upon the aggregation of statoliths. 
C) results from relatively rapid elongation of some stem cells. 
D) A and B only 
E) A, B and C 
A) depends upon auxin distribution. 
B) depends upon the aggregation of statoliths. 
C) results from relatively rapid elongation of some stem cells. 
D) A and B only 
E) A, B and C

Question 6

If a scientist discovers an Arabidopsis mutant that does not store starch in plastids but has normal gravitropic bending, what aspect of our understanding would need to be reevaluated?

Accepted Answer

A) the role of auxin in gravitropism 
B) the role of calcium in gravitropism 
C) the role of statoliths in gravitropism 
D) the role of light in gravitropism 
E) the role of differential growth in gravitropic bending 
A) the role of auxin in gravitropism 
B) the role of calcium in gravitropism 
C) the role of statoliths in gravitropism 
D) the role of light in gravitropism 
E) the role of differential growth in gravitropic bending

Question 7

Which one of the following is not a direct function of either auxin or gibberellin?

Accepted Answer

A) inducing semescence and ripening 
B) producing apical dominance 
C) producing positive geotropism of shoots 
D) stimulating cell elongation 
E) breaking dormancy in seeds 
A) inducing semescence and ripening 
B) producing apical dominance 
C) producing positive geotropism of shoots 
D) stimulating cell elongation 
E) breaking dormancy in seeds

Question 8

Cells elongate in response to auxin. All of the following are part of the acid growth hypothesis except

Accepted Answer

A) Auxin stimulates proton pumps in cell membranes. 
B) Lowered pH results in the breakage of cross-links between cellulose microfibrils. 
C) The wall fabric becomes looser (more plastic). 
D) Auxin-activated proton pumps stimulate cell division in meristems. 
E) The turgor pressure of the cell exceeds the restraining pressure of the loosened cell wall, and the cell takes up water and elongates. 
A) Auxin stimulates proton pumps in cell membranes. 
B) Lowered pH results in the breakage of cross-links between cellulose microfibrils. 
C) The wall fabric becomes looser (more plastic). 
D) Auxin-activated proton pumps stimulate cell division in meristems. 
E) The turgor pressure of the cell exceeds the restraining pressure of the loosened cell wall, and the cell takes up water and elongates.

Question 9

External stimuli would be received most quickly by a plant cell if the receptors for signal transduction were located in the

Accepted Answer

A) cell membrane. 
B) cytoplasmic matrix. 
C) endoplasmic reticulum. 
D) nuclear membrane. 
E) nucleoplasm. 
A) cell membrane. 
B) cytoplasmic matrix. 
C) endoplasmic reticulum. 
D) nuclear membrane. 
E) nucleoplasm.

Question 10

Plants often use changes in day length (photoperiod)to trigger events such as dormancy and flowering. It is logical that plants have evolved this mechanism because photoperiod changes

Accepted Answer

A) are more predictable than air temperature changes. 
B) alter the amount of energy available to the plant. 
C) are modified by soil temperature changes. 
D) can reset the biological clock. 
E) are correlated with moisture availability. 
A) are more predictable than air temperature changes. 
B) alter the amount of energy available to the plant. 
C) are modified by soil temperature changes. 
D) can reset the biological clock. 
E) are correlated with moisture availability.

Question 11

According to modern ideas about phototropism in plants,

Accepted Answer

A) light causes auxin to accumulate on the shaded side of a plant stem. 
B) auxin stimulates elongation of plant stem cells. 
C) auxin is produced by the tip of the coleoptile and moves downward. 
D) A and B only 
E) A, B and C 
A) light causes auxin to accumulate on the shaded side of a plant stem. 
B) auxin stimulates elongation of plant stem cells. 
C) auxin is produced by the tip of the coleoptile and moves downward. 
D) A and B only 
E) A, B and C

Question 12

Why do coleoptiles grow toward light?

Accepted Answer

A) Auxin is destroyed by light. 
B) Gibberellins are destroyed by light. 
C) Auxin synthesis is stimulated in the dark. 
D) Auxin moves away from the light to the shady side. 
E) Gibberellins move away from the light to the shady side. 
A) Auxin is destroyed by light. 
B) Gibberellins are destroyed by light. 
C) Auxin synthesis is stimulated in the dark. 
D) Auxin moves away from the light to the shady side. 
E) Gibberellins move away from the light to the shady side.

Question 13

The cells of lateral buds are more sensitive to auxin than stem cells.

Accepted Answer

A) True 
 B)False

Question 14

Charles and Francis Darwin discovered that

Accepted Answer

A) auxin is responsible for phototropic curvature. 
B) auxin can pass through agar. 
C) light destroys auxin. 
D) light is perceived by the tips of coleoptiles. 
E) red light is most effective in causing phototropic curvatures. 
A) auxin is responsible for phototropic curvature. 
B) auxin can pass through agar. 
C) light destroys auxin. 
D) light is perceived by the tips of coleoptiles. 
E) red light is most effective in causing phototropic curvatures.

Question 15

Which plant hormones might be used to enhance stem elongation and fruit growth?

Accepted Answer

A) brassinosteroids and oligosaccharides 
B) auxins and gibberellins 
C) abscisic acid and phytochrome 
D) ethylene and cytokinins 
E) phytochrome and flowering hormone 
A) brassinosteroids and oligosaccharides 
B) auxins and gibberellins 
C) abscisic acid and phytochrome 
D) ethylene and cytokinins 
E) phytochrome and flowering hormone

Question 16

Classic experiments suggested that a floral stimulus Florigen could move across a graft from an induced plant to a noninduced plant and trigger flowering. Recent evidence using Arabidopsis has recently shown that florigen is probably

Accepted Answer

A) a phytochrome molecule that is activated by red light. 
B) a protein that is synthesized in leaves and travels to the shoot apical meristem and initiates flowering. 
C) a membrane signal that travels through the symplast from leaves to buds. 
D) a second messenger that induces Ca++ ions to change membrane potential. 
E) a transcription factor that controls the activation of florigen specific genes. 
A) a phytochrome molecule that is activated by red light. 
B) a protein that is synthesized in leaves and travels to the shoot apical meristem and initiates flowering. 
C) a membrane signal that travels through the symplast from leaves to buds. 
D) a second messenger that induces Ca++ ions to change membrane potential. 
E) a transcription factor that controls the activation of florigen specific genes.

Question 17

Seed packets give a recommended planting depth for the enclosed seeds. The most likely reason some seeds are to be covered with only 1/4 inch of soil is that the

Accepted Answer

A) seedlings do not produce a hypocotyl. 
B) seedlings do not have an etiolation response. 
C) seeds require light to germinate. 
D) seeds require a higher temperature to germinate. 
E) seeds are very sensitive to waterlogging. 
A) seedlings do not produce a hypocotyl. 
B) seedlings do not have an etiolation response. 
C) seeds require light to germinate. 
D) seeds require a higher temperature to germinate. 
E) seeds are very sensitive to waterlogging.

Question 18

Plant growth regulators can be characterized by all of the following except that they

Accepted Answer

A) may act by altering gene expression. 
B) have a multiplicity of effects. 
C) function independently of other hormones. 
D) control plant growth and development. 
E) affect division, elongation, and differentiation of cells. 
A) may act by altering gene expression. 
B) have a multiplicity of effects. 
C) function independently of other hormones. 
D) control plant growth and development. 
E) affect division, elongation, and differentiation of cells.

Question 19

The rapid leaf movements resulting from a response to touch (thigmotropism)involve transmission of electrical impulses called action potentials.

Accepted Answer

A) True 
 B)False

Question 20

Which of these conclusions is supported by the research of both Went and Charles and Francis Darwin on shoot responses to light?

Accepted Answer

A) When shoots are exposed to light, a chemical substance migrates toward the light. 
B) Agar contains a chemical substance that mimics a plant hormone. 
C) A chemical substance involved in shoot bending is produced in shoot tips. 
D) Once shoot tips have been cut, normal growth cannot be induced. 
E) Light stimulates the synthesis of a plant hormone that responds to light. 
A) When shoots are exposed to light, a chemical substance migrates toward the light. 
B) Agar contains a chemical substance that mimics a plant hormone. 
C) A chemical substance involved in shoot bending is produced in shoot tips. 
D) Once shoot tips have been cut, normal growth cannot be induced. 
E) Light stimulates the synthesis of a plant hormone that responds to light.

Exam 39: Plant Responses to Internal and External Signals

Which of the following are examples or parts of plants' systemic acquired resistance against infection?

Plant hormonal control differs from animal hormonal control in that there are no separate hormone producing organs in plants as there are in animals.

A short-day plant will flower only when

Which of the following hormones would be most useful in promoting the rooting of plant cuttings?

Negative gravitropism of plant shoots

If a scientist discovers an Arabidopsis mutant that does not store starch in plastids but has normal gravitropic bending, what aspect of our understanding would need to be reevaluated?

Which one of the following is not a direct function of either auxin or gibberellin?

Cells elongate in response to auxin. All of the following are part of the acid growth hypothesis except

External stimuli would be received most quickly by a plant cell if the receptors for signal transduction were located in the

Plants often use changes in day length (photoperiod)to trigger events such as dormancy and flowering. It is logical that plants have evolved this mechanism because photoperiod changes

According to modern ideas about phototropism in plants,

Why do coleoptiles grow toward light?

The cells of lateral buds are more sensitive to auxin than stem cells.

Charles and Francis Darwin discovered that

Which plant hormones might be used to enhance stem elongation and fruit growth?

Classic experiments suggested that a floral stimulus Florigen could move across a graft from an induced plant to a noninduced plant and trigger flowering. Recent evidence using Arabidopsis has recently shown that florigen is probably

Seed packets give a recommended planting depth for the enclosed seeds. The most likely reason some seeds are to be covered with only 1/4 inch of soil is that the

Plant growth regulators can be characterized by all of the following except that they

The rapid leaf movements resulting from a response to touch (thigmotropism)involve transmission of electrical impulses called action potentials.

Which of these conclusions is supported by the research of both Went and Charles and Francis Darwin on shoot responses to light?

Introduction: Themes in the Study of Life

The Chemical Context of Life

Water and the Fitness of the Environment

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: Harvesting Chemical Energy

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

Control 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 Introduction to Animal Diversity

Invertebrates

Vertebrates

Plant Structure, Growth, and Development

Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

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

Conservation Biology and Restoration Ecology

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