Question 1

Which of the following is not presently considered a major mechanism whereby hormones control plant development?

Accepted Answer

A) affecting cell respiration via regulation of the citric acid cycle 
B) affecting cell division via the cell cycle 
C) affecting cell elongation through acid growth 
D) affecting cell differentiation through altered gene activity 
E) mediating short-term physiological responses to environmental stimuli 
A) affecting cell respiration via regulation of the citric acid cycle 
B) affecting cell division via the cell cycle 
C) affecting cell elongation through acid growth 
D) affecting cell differentiation through altered gene activity 
E) mediating short-term physiological responses to environmental stimuli

Question 2

The transduction pathway that activates systemic acquired resistance in plants is initially signaled by

Accepted Answer

A) antisense RNA. 
B) Pfr phytochrome. 
C) salicylic acid. 
D) abscisic acid. 
E) red, but not far-red, light. 
A) antisense RNA. 
B) Pfr phytochrome. 
C) salicylic acid. 
D) abscisic acid. 
E) red, but not far-red, light.

Question 3

Plants that have their flowering inhibited by being exposed to bright lights at night are

Accepted Answer

A) day-neutral plants. 
B) short-night plants. 
C) devoid of phytochrome. 
D) short-day plants. 
E) long-day plants. 
A) day-neutral plants. 
B) short-night plants. 
C) devoid of phytochrome. 
D) short-day plants. 
E) long-day plants.

Question 4

The synthesis of which of the following hormones would be a logical first choice in an attempt to produce normal growth in mutant dwarf plants?

Accepted Answer

A) indoleacetic acid 
B) cytokinin 
C) gibberellin 
D) abscisic acid 
E) ethylene 
A) indoleacetic acid 
B) cytokinin 
C) gibberellin 
D) abscisic acid 
E) ethylene

Question 5

A plant seedling bends toward sunlight because

Accepted Answer

A) auxin migrates to the lower part of the stem due to gravity. 
B) there is more auxin on the light side of the stem. 
C) auxin is destroyed more quickly on the dark side of the stem. 
D) auxin is found in greatest abundance on the dark side of the stem. 
E) gibberellins produced at the stem tip cause phototropism. 
A) auxin migrates to the lower part of the stem due to gravity. 
B) there is more auxin on the light side of the stem. 
C) auxin is destroyed more quickly on the dark side of the stem. 
D) auxin is found in greatest abundance on the dark side of the stem. 
E) gibberellins produced at the stem tip cause phototropism.

Question 6

Which of the following is not a typical component of a signal transduction pathway?

Accepted Answer

A) production of more signal 
B) production of second messengers such as cGMP 
C) expression of specific proteins 
D) activation of protein kinases 
E) phosphorylation of transcription factors 
A) production of more signal 
B) production of second messengers such as cGMP 
C) expression of specific proteins 
D) activation of protein kinases 
E) phosphorylation of transcription factors

Question 7

Which of the following is currently the most powerful method of research on plant hormones?

Accepted Answer

A) comparing of photoperiodic responses 
B) comparing tropisms with turgor movements 
C) subjecting plants to unusual stresses 
D) studying phytochromes 
E) analyzing mutant plants 
A) comparing of photoperiodic responses 
B) comparing tropisms with turgor movements 
C) subjecting plants to unusual stresses 
D) studying phytochromes 
E) analyzing mutant plants

Question 8

A long-day plant will flower if

Accepted Answer

A) the duration of continuous light exceeds a critical length. 
B) the duration of continuous light is less than a critical length. 
C) the duration of continuous darkness exceeds a critical length. 
D) the duration of continuous darkness is less than a critical length. 
E) it is kept in continuous far-red light. 
A) the duration of continuous light exceeds a critical length. 
B) the duration of continuous light is less than a critical length. 
C) the duration of continuous darkness exceeds a critical length. 
D) the duration of continuous darkness is less than a critical length. 
E) it is kept in continuous far-red light.

Question 9

In attempting to make a seed break dormancy, one logically could treat it with

Accepted Answer

A) IAA. 
B) 2, 4-D. 
C) CO2. 
D) gibberellins. 
E) abscisic acid. 
A) IAA. 
B) 2, 4-D. 
C) CO2. 
D) gibberellins. 
E) abscisic acid.

Question 10

All of the following are responses of plants to cold stress except

Accepted Answer

A) the production of a specific solute "plant antifreeze" that reduces water loss. 
B) excluding ice crystals from the interior walls. 
C) conversion of the fluid mosaic cell membrane to a solid mosaic one. 
D) an alteration of membrane lipids so that the membranes remain flexible. 
E) increasing the proportion of unsaturated fatty acids in the membranes. 
A) the production of a specific solute "plant antifreeze" that reduces water loss. 
B) excluding ice crystals from the interior walls. 
C) conversion of the fluid mosaic cell membrane to a solid mosaic one. 
D) an alteration of membrane lipids so that the membranes remain flexible. 
E) increasing the proportion of unsaturated fatty acids in the membranes.

Question 11

What do results of research on gravitropic responses of roots and stems show?

Accepted Answer

A) Different tissues have the same response to auxin. 
B) The effect of a plant hormone can depend on the tissue. 
C) Some responses of plants require no hormones at all. 
D) Light is required for the gravitropic response. 
E) Cytokinin can only function in the presence of auxin. 
A) Different tissues have the same response to auxin. 
B) The effect of a plant hormone can depend on the tissue. 
C) Some responses of plants require no hormones at all. 
D) Light is required for the gravitropic response. 
E) Cytokinin can only function in the presence of auxin.

Question 12

The apical bud of a pine tree inhibits the growth of lateral buds through the production of

Accepted Answer

A) abscisic acid. 
B) ethylene. 
C) cytokinin. 
D) gibberellin. 
E) auxin. 
A) abscisic acid. 
B) ethylene. 
C) cytokinin. 
D) gibberellin. 
E) auxin.

Question 13

Auxins (IAA)in plants are known to affect all of the following phenomena except

Accepted Answer

A) geotropism of shoots. 
B) maintenance of dormancy. 
C) phototropism of shoots. 
D) inhibition of lateral buds. 
E) fruit development. 
A) geotropism of shoots. 
B) maintenance of dormancy. 
C) phototropism of shoots. 
D) inhibition of lateral buds. 
E) fruit development.

Question 14

In systemic acquired resistance, salicylic acid probably

Accepted Answer

A) destroys pathogens directly. 
B) activates defenses throughout the plant before infection spreads. 
C) closes stomata, thus preventing the entry of pathogens. 
D) activates heat-shock proteins. 
E) sacrifices infected tissues by hydrolyzing cells. 
A) destroys pathogens directly. 
B) activates defenses throughout the plant before infection spreads. 
C) closes stomata, thus preventing the entry of pathogens. 
D) activates heat-shock proteins. 
E) sacrifices infected tissues by hydrolyzing cells.

Question 15

In order for a plant to initiate chemical responses to herbivory,

Accepted Answer

A) the plant must be directly attacked by an herbivore. 
B) volatile "signal" compounds must be perceived. 
C) gene-for-gene recognition must occur. 
D) phytoalexins must be released. 
E) all of the above must happen. 
A) the plant must be directly attacked by an herbivore. 
B) volatile "signal" compounds must be perceived. 
C) gene-for-gene recognition must occur. 
D) phytoalexins must be released. 
E) all of the above must happen.

Question 16

One effect of gibberellins is to stimulate cereal seeds to produce

Accepted Answer

A) RuBP carboxylase. 
B) lipids. 
C) abscisic acid. 
D) starch. 
E) amylase. 
A) RuBP carboxylase. 
B) lipids. 
C) abscisic acid. 
D) starch. 
E) amylase.

Question 17

A long-day plant will flower only when the night is longer than a critical value.

Accepted Answer

A) True 
 B)False

Question 18

A botanist exposed two groups of the same plant species to two photoperiods-one with 14 hours of light and 10 hours of dark and the other with 10 hours of light and 14 hours of dark. Under the first set of conditions, the plants flowered, but they failed to flower under the second set of conditions. Which of the following conclusions would be consistent with these results?

Accepted Answer

A) The critical night length is 14 hours. 
B) The plants are short-day plants. 
C) The critical day length is 10 hours. 
D) The plants can convert phytochrome to florigen. 
E) The plants flower in the spring. 
A) The critical night length is 14 hours. 
B) The plants are short-day plants. 
C) The critical day length is 10 hours. 
D) The plants can convert phytochrome to florigen. 
E) The plants flower in the spring.

Question 19

Incandescent light bulbs, which have high output of red light, are least effective in promoting

Accepted Answer

A) photosynthesis. 
B) seed germination. 
C) phototropism. 
D) flowering. 
E) entrainment of circadian rhythms. 
A) photosynthesis. 
B) seed germination. 
C) phototropism. 
D) flowering. 
E) entrainment of circadian rhythms.

Question 20

Plants are affected by an array of pathogens. Which of the following is not a plant defense against disease?

Accepted Answer

A) cells near the point of infection destroying themselves to prevent the spread of the infection 
B) production of chemicals that kill pathogens 
C) acquiring gene-for-gene recognition that allows specific proteins to interact so that the plant can produce defenses against the pathogen 
D) a waxy cuticle that pathogens have trouble penetrating 
E) All of the above are plant defenses against disease. 
A) cells near the point of infection destroying themselves to prevent the spread of the infection 
B) production of chemicals that kill pathogens 
C) acquiring gene-for-gene recognition that allows specific proteins to interact so that the plant can produce defenses against the pathogen 
D) a waxy cuticle that pathogens have trouble penetrating 
E) All of the above are plant defenses against disease.

Exam 39: Plant Responses to Internal and External Signals

Which of the following is not presently considered a major mechanism whereby hormones control plant development?

The transduction pathway that activates systemic acquired resistance in plants is initially signaled by

Plants that have their flowering inhibited by being exposed to bright lights at night are

The synthesis of which of the following hormones would be a logical first choice in an attempt to produce normal growth in mutant dwarf plants?

A plant seedling bends toward sunlight because

Which of the following is not a typical component of a signal transduction pathway?

Which of the following is currently the most powerful method of research on plant hormones?

A long-day plant will flower if

In attempting to make a seed break dormancy, one logically could treat it with

All of the following are responses of plants to cold stress except

What do results of research on gravitropic responses of roots and stems show?

The apical bud of a pine tree inhibits the growth of lateral buds through the production of

Auxins (IAA)in plants are known to affect all of the following phenomena except

In systemic acquired resistance, salicylic acid probably

In order for a plant to initiate chemical responses to herbivory,

One effect of gibberellins is to stimulate cereal seeds to produce

A long-day plant will flower only when the night is longer than a critical value.

Incandescent light bulbs, which have high output of red light, are least effective in promoting

Plants are affected by an array of pathogens. Which of the following is not a plant defense against disease?

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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