Question 1

Plant hormones produce their effects by

Accepted Answer

A) altering the expression of genes. 
B) modifying the structure of the hormones. 
C) modifying the structure of the nuclear envelope membrane. 
D) altering the expression of genes and modifying the permeability of the plasma membrane. 
A) altering the expression of genes. 
B) modifying the structure of the hormones. 
C) modifying the structure of the nuclear envelope membrane. 
D) altering the expression of genes and modifying the permeability of the plasma membrane. D

Question 2

Which of the following best explains both the growth of a vine up the trunk of a tree and the directional growth of a houseplant toward a window?

Accepted Answer

A) nastic movement 
B) taxic movement 
C) tropism response 
D) morphological response 
A) nastic movement 
B) taxic movement 
C) tropism response 
D) morphological response C

Question 3

Which plant organ detects changes in the photoperiod and produces signaling molecules that cue buds to develop as flowers?

Accepted Answer

A) stem 
B) petiole 
C) root 
D) leaf 
A) stem 
B) petiole 
C) root 
D) leaf D

Question 4

In nature,poinsettias bloom in early March.Research has shown that the flowering process is triggered 3 months before blooming occurs.In order to make poinsettias bloom in December,florists change the length of the light/dark cycle in September.Given this information and clues,which of the following is a correct statement about poinsettias?

Accepted Answer

A) They are short-day plants. 
B) They require a light period longer than some set minimum. 
C) They require a shorter dark period than is available in September. 
D) The dark period can be interrupted without affecting flowering. 
A) They are short-day plants. 
B) They require a light period longer than some set minimum. 
C) They require a shorter dark period than is available in September. 
D) The dark period can be interrupted without affecting flowering.

Question 5

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. 
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.

Question 6

Which of the following most correctly describes the effect of most hormones that control growth and development?

Accepted Answer

A) individual hormonal action 
B) interaction between hormones 
C) chemical nature of hormones 
D) availability of nutrients 
A) individual hormonal action 
B) interaction between hormones 
C) chemical nature of hormones 
D) availability of nutrients

Question 7

Which one of the following plants has thigmotropism?

Accepted Answer

A) Mimosa pudica 
B) chrysanthemum 
C) rose 
D) dandelion 
A) Mimosa pudica 
B) chrysanthemum 
C) rose 
D) dandelion

Question 8

Trichomes on certain plant species are a ________ to prevent excessive herbivory.

Accepted Answer

A) physical defense 
B) chemical defense 
C) behavioral defense 
D) combination of chemical and behavioral defense 
A) physical defense 
B) chemical defense 
C) behavioral defense 
D) combination of chemical and behavioral defense

Question 9

Which of the following conclusions is supported by the research of both Frits 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. 
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.

Question 10

Which of the following is the most likely plant response to an attack by herbivores?

Accepted Answer

A) leaf abscission to prevent further loss 
B) early flowering to try to reproduce before being eaten 
C) production of chemical compounds for defense or to attract predators 
D) production of physical defenses,such as thorns 
A) leaf abscission to prevent further loss 
B) early flowering to try to reproduce before being eaten 
C) production of chemical compounds for defense or to attract predators 
D) production of physical defenses,such as thorns

Question 11

Charles and Francis Darwin discovered that

Accepted Answer

A) red light is most effective in shoot phototropism. 
B) auxin can pass through agar. 
C) light destroys auxin. 
D) light is perceived by the tips of coleoptiles. 
A) red light is most effective in shoot phototropism. 
B) auxin can pass through agar. 
C) light destroys auxin. 
D) light is perceived by the tips of coleoptiles.

Question 12

This experiment suggests that the unknown amount of gibberellin in the experimental plant (B)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 13

Which plant hormone affects the response to mechanical stress,senescence,leaf abscission,and fruit ripening?

Accepted Answer

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

Question 14

Why are axillary buds often inhibited from growing even though a stem may be actively elongating?

Accepted Answer

A) The cells of axillary buds respond differently to auxin than stem cells. 
B) Axillary buds are high in abscisic acid that prevents elongation. 
C) Axillary buds are low in gibberellins. 
D) Stem cells lack receptors for auxin. 
A) The cells of axillary buds respond differently to auxin than stem cells. 
B) Axillary buds are high in abscisic acid that prevents elongation. 
C) Axillary buds are low in gibberellins. 
D) Stem cells lack receptors for auxin.

Question 15

Statoliths are structures that are responsible for

Accepted Answer

A) phototropism. 
B) gravitropism. 
C) thigmotropism. 
D) dormancy. 
A) phototropism. 
B) gravitropism. 
C) thigmotropism. 
D) dormancy.

Question 16

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) short-day plants. 
D) long-day plants. 
A) day-neutral plants. 
B) short-night plants. 
C) short-day plants. 
D) long-day plants.

Question 17

The application 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 
A) indoleacetic acid 
B) cytokinin 
C) gibberellin 
D) abscisic acid

Question 18

________ is produced in roots and moves up the plant in xylem sap to influence organ formation.

Accepted Answer

A) Cytokinin 
B) Ethylene 
C) Abscisic acid 
D) Auxin 
A) Cytokinin 
B) Ethylene 
C) Abscisic acid 
D) Auxin

Question 19

During the process of etiolation,a morphological adaptation in potato plant growth,which of the following activities takes place?

Accepted Answer

A) expanded and above ground leaves 
B) excessive loss of water through stomata 
C) extensive root system 
D) elongated stems 
A) expanded and above ground leaves 
B) excessive loss of water through stomata 
C) extensive root system 
D) elongated stems

Question 20

Auxin transports from cell to cell

Accepted Answer

A) from top to bottom. 
B) from the bottom up. 
C) from side to side. 
D) in multidirectional ways. 
A) from top to bottom. 
B) from the bottom up. 
C) from side to side. 
D) in multidirectional ways.

Exam 31: Plant Responses to Internal and External Signals

Plant hormones produce their effects by

Which of the following best explains both the growth of a vine up the trunk of a tree and the directional growth of a houseplant toward a window?

Which plant organ detects changes in the photoperiod and produces signaling molecules that cue buds to develop as flowers?

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

Which of the following most correctly describes the effect of most hormones that control growth and development?

Which one of the following plants has thigmotropism?

Trichomes on certain plant species are a ________ to prevent excessive herbivory.

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

Which of the following is the most likely plant response to an attack by herbivores?

Charles and Francis Darwin discovered that

This experiment suggests that the unknown amount of gibberellin in the experimental plant (B)is approximately

Which plant hormone affects the response to mechanical stress,senescence,leaf abscission,and fruit ripening?

Why are axillary buds often inhibited from growing even though a stem may be actively elongating?

Statoliths are structures that are responsible for

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

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

________ is produced in roots and moves up the plant in xylem sap to influence organ formation.

During the process of etiolation,a morphological adaptation in potato plant growth,which of the following activities takes place?

Auxin transports from cell to cell

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

Filters