Question 1

The ripening of fruit and the dropping of leaves and fruit are principally controlled by

Accepted Answer

A) auxins. 
B) cytokinins. 
C) indoleacetic acid (IA
A) . 
D) ethylene. 
A) auxins. 
B) cytokinins. 
C) indoleacetic acid (IA
A) . 
D) ethylene.

Question 2

The variety of leaf patterns in plants is due to

Accepted Answer

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

Question 3

Which of the following plant hormones stimulates cell elongation?

Accepted Answer

A) cytokinin 
B) ethylene 
C) abscisic acid 
D) auxin 
A) cytokinin 
B) ethylene 
C) abscisic acid 
D) auxin

Question 4

Young leaves and developing seeds are the prime sites for ________ synthesis.

Accepted Answer

A) auxin 
B) gibberellin 
C) cytokinin 
D) ethylene 
A) auxin 
B) gibberellin 
C) cytokinin 
D) ethylene

Question 5

If a short-day plant has a critical night length of 15 hours,then which of the following 24-hour cycles will prevent flowering?

Accepted Answer

A) 8 hours light/16 hours dark 
B) 4 hours light/20 hours dark 
C) 6 hours light/2 hours dark/light flash/16 hours dark 
D) 8 hours light/8 hours dark/light flash/8 hours dark 
A) 8 hours light/16 hours dark 
B) 4 hours light/20 hours dark 
C) 6 hours light/2 hours dark/light flash/16 hours dark 
D) 8 hours light/8 hours dark/light flash/8 hours dark

Question 6

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. 
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.

Question 7

Which of the following plant hormones stimulates cell division and differentiation and apical dominance?

Accepted Answer

A) abscisic acid 
B) auxin 
C) ethylene 
D) cytokinin 
A) abscisic acid 
B) auxin 
C) ethylene 
D) cytokinin

Question 8

The apical bud of a shoot produces ________,resulting in the inhibition of lateral bud growth.

Accepted Answer

A) abscisic acid 
B) ethylene 
C) cytokinin 
D) auxin 
A) abscisic acid 
B) ethylene 
C) cytokinin 
D) auxin

Question 9

This experiment suggests that the optimum amount of gibberellin in the experiment is approximately

Accepted Answer

A) zero. 
B) 0.01 μg/mL. 
C) 0.1 μg/mL. 
D) 1.0 μg/mL. 
A) zero. 
B) 0.01 μg/mL. 
C) 0.1 μg/mL. 
D) 1.0 μg/mL.

Question 10

The rapid leaf movements resulting from a response to touch (thigmotropism)primarily involve

Accepted Answer

A) rapid growth response. 
B) potassium channels. 
C) nervous tissue. 
D) aquaporins. 
A) rapid growth response. 
B) potassium channels. 
C) nervous tissue. 
D) aquaporins.

Question 11

The initial response of the root cells of a tomato plant watered with seawater would be to

Accepted Answer

A) rapidly produce organic solutes in the cytoplasm. 
B) rapidly expand until the cells burst. 
C) begin to plasmolyze as water is lost. 
D) actively transport water from the cytoplasm into the vacuole. 
A) rapidly produce organic solutes in the cytoplasm. 
B) rapidly expand until the cells burst. 
C) begin to plasmolyze as water is lost. 
D) actively transport water from the cytoplasm into the vacuole.

Question 12

After some time,the tip of a plant that has been forced into a horizontal position grows upward.This phenomenon is related to

Accepted Answer

A) calcium release from the endoplasmic reticulum of shaded cells. 
B) whether the plant is in the northern or southern hemisphere. 
C) auxin production in cells receiving red light. 
D) auxin movement toward the lower side of the stem. 
A) calcium release from the endoplasmic reticulum of shaded cells. 
B) whether the plant is in the northern or southern hemisphere. 
C) auxin production in cells receiving red light. 
D) auxin movement toward the lower side of the stem.

Question 13

When an arborist prunes a limb off a valuable tree,he or she usually paints the cut surface.The primary purpose of the paint is to

Accepted Answer

A) minimize water loss by evaporation from the cut surface. 
B) improve the appearance of the cut surface. 
C) stimulate growth of the cork cambium to "heal" the wound. 
D) block entry of pathogens through the wound. 
A) minimize water loss by evaporation from the cut surface. 
B) improve the appearance of the cut surface. 
C) stimulate growth of the cork cambium to "heal" the wound. 
D) block entry of pathogens through the wound.

Question 14

In an experiment,a plant physiologist has four groups of bananas of the same species.He exposes each of the four groups of bananas with the same concentration of auxins,gibberellins,abscisic acid,or ethylene.Which of these four groups of bananas ripen the fastest?

Accepted Answer

A) auxins 
B) gibberellins 
C) abscisic acid 
D) ethylene 
A) auxins 
B) gibberellins 
C) abscisic acid 
D) ethylene

Question 15

Which of the following chemicals functions as a photoreceptor in plants and regulates photoperiodism and responses to seasons?

Accepted Answer

A) phytochromes 
B) auxins 
C) gibberellins 
D) cytokinins 
A) phytochromes 
B) auxins 
C) gibberellins 
D) cytokinins

Question 16

Which of the following plant hormones plays a critical role on stomatal closures to avoid wilting?

Accepted Answer

A) abscisic acid 
B) gibberellins 
C) ethylene 
D) cytokinin 
A) abscisic acid 
B) gibberellins 
C) ethylene 
D) cytokinin

Question 17

When growing plants in culture,IAA is used to stimulate cell enlargement.Which plant growth regulator has to now be added to stimulate cell division?

Accepted Answer

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

Question 18

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. 
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.

Question 19

What is the probable role of salicylic acid in the defense responses of plants?

Accepted Answer

A) to destroy pathogens directly 
B) to activate the systemic acquired resistance of plants 
C) to close stomata,thus preventing the entry of pathogens 
D) to activate heat-shock proteins 
A) to destroy pathogens directly 
B) to activate the systemic acquired resistance of plants 
C) to close stomata,thus preventing the entry of pathogens 
D) to activate heat-shock proteins

Question 20

Which of the following is a long-day plant?

Accepted Answer

A) soybean 
B) spinach 
C) chrysanthemum 
D) poinsettia 
A) soybean 
B) spinach 
C) chrysanthemum 
D) poinsettia

Exam 31: Plant Responses to Internal and External Signals

The ripening of fruit and the dropping of leaves and fruit are principally controlled by

The variety of leaf patterns in plants is due to

Which of the following plant hormones stimulates cell elongation?

Young leaves and developing seeds are the prime sites for ________ synthesis.

If a short-day plant has a critical night length of 15 hours,then which of the following 24-hour cycles will prevent flowering?

Why do coleoptiles grow toward light?

Which of the following plant hormones stimulates cell division and differentiation and apical dominance?

The apical bud of a shoot produces ________,resulting in the inhibition of lateral bud growth.

This experiment suggests that the optimum amount of gibberellin in the experiment is approximately

The rapid leaf movements resulting from a response to touch (thigmotropism)primarily involve

The initial response of the root cells of a tomato plant watered with seawater would be to

After some time,the tip of a plant that has been forced into a horizontal position grows upward.This phenomenon is related to

When an arborist prunes a limb off a valuable tree,he or she usually paints the cut surface.The primary purpose of the paint is to

In an experiment,a plant physiologist has four groups of bananas of the same species.He exposes each of the four groups of bananas with the same concentration of auxins,gibberellins,abscisic acid,or ethylene.Which of these four groups of bananas ripen the fastest?

Which of the following chemicals functions as a photoreceptor in plants and regulates photoperiodism and responses to seasons?

Which of the following plant hormones plays a critical role on stomatal closures to avoid wilting?

When growing plants in culture,IAA is used to stimulate cell enlargement.Which plant growth regulator has to now be added to stimulate cell division?

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

What is the probable role of salicylic acid in the defense responses of plants?

Which of the following is a long-day plant?

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

Resource Acquisition,nutrition,and Transport in Vascular Plants

Reproduction and Domestication of Flowering Plants

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

Ecological Communities

Ecosystems and Energy

Conservation Biology and Global Change

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