Question 1

Which of the following hormones would never be found in high concentrations in a dormant overwintering flower bud?

Accepted Answer

A) auxin 
B) cytokinins 
C) abscisic acid 
D) ethylene 
E) gibberellins 
A) auxin 
B) cytokinins 
C) abscisic acid 
D) ethylene 
E) gibberellins

Question 2

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. 
E) induce the production of phytoalexins. 
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. 
E) induce the production of phytoalexins.

Question 3

Which of the following statements is correct with regards to a "circadian rhythm" in plants?

Accepted Answer

A) It may have the same signal transduction pathway in all organisms. 
B) Once set, it cannot be changed. 
C) It works independently of photoperiodic responses. 
D) Once set, it is independent of external signals. 
E) It can be changed to a longer or shorter period by altering the light quality. 
A) It may have the same signal transduction pathway in all organisms. 
B) Once set, it cannot be changed. 
C) It works independently of photoperiodic responses. 
D) Once set, it is independent of external signals. 
E) It can be changed to a longer or shorter period by altering the light quality.

Question 4

How may a plant respond to severe heat stress?

Accepted Answer

A) by reorienting leaves to increase evaporative cooling 
B) by creating air tubes for ventilation 
C) by initiating a systemic acquired resistance response 
D) by increasing the proportion of unsaturated fatty acids in cell membranes, reducing their fluidity 
E) by producing heat-shock proteins, which may protect the plant's proteins from denaturing 
A) by reorienting leaves to increase evaporative cooling 
B) by creating air tubes for ventilation 
C) by initiating a systemic acquired resistance response 
D) by increasing the proportion of unsaturated fatty acids in cell membranes, reducing their fluidity 
E) by producing heat-shock proteins, which may protect the plant's proteins from denaturing

Question 5

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 6

Gravitropism in plant shoots and roots differ in that

Accepted Answer

A) only shoots depend upon auxin distribution. 
B) only shoots depend upon the aggregation of statoliths. 
C) only roots exhibit rapid elongation of specific cells. 
D) only roots sense gravity at the tips. 
E) the threshold and response time is much less in shoots than in roots. 
A) only shoots depend upon auxin distribution. 
B) only shoots depend upon the aggregation of statoliths. 
C) only roots exhibit rapid elongation of specific cells. 
D) only roots sense gravity at the tips. 
E) the threshold and response time is much less in shoots than in roots.

Question 7

Which of the following plant hormones are most likely to act synergistically if expressed or applied to a drought-stricken plant?

Accepted Answer

A) auxin and ethylene 
B) phytochrome and gibberellins 
C) gibberellins and abscisic acid 
D) abscisic acid and ethylene 
E) brassinosteroids and cytokinins 
A) auxin and ethylene 
B) phytochrome and gibberellins 
C) gibberellins and abscisic acid 
D) abscisic acid and ethylene 
E) brassinosteroids and cytokinins

Question 8

The results of this experiment, shown on the left of the graph (area

Accepted Answer

A) show that these plants can live without gibberellin. 
B) show that gibberellin is necessary in positive gravitropism. 
C) show that taller plants with more gibberellin produce fruit (pods). 
D) show a correlation between plant height and gibberellin concentration. 
E) study phytoalexins in plants. 
A) show that these plants can live without gibberellin. 
B) show that gibberellin is necessary in positive gravitropism. 
C) show that taller plants with more gibberellin produce fruit (pods). 
D) show a correlation between plant height and gibberellin concentration. 
E) study phytoalexins in plants.

Question 9

Evidence for phototropism due to the asymmetric distribution of auxin moving down the stem

Accepted Answer

A) was first demonstrated in the coleoptiles of monocots. 
B) has been found in all monocots and most eudicots. 
C) has been shown to involve only IAA stimulation of cell elongation on the dark side of the stem. 
D) can be demonstrated with unilateral red light, but not blue light. 
E) is now thought by most plant scientists not to involve the shoot tip. 
A) was first demonstrated in the coleoptiles of monocots. 
B) has been found in all monocots and most eudicots. 
C) has been shown to involve only IAA stimulation of cell elongation on the dark side of the stem. 
D) can be demonstrated with unilateral red light, but not blue light. 
E) is now thought by most plant scientists not to involve the shoot tip.

Question 10

Which of the following plant hormones would most likely be found in high concentrations in a mature, slightly overripe fruit?

Accepted Answer

A) auxins and cytokinins 
B) auxins and abscisic acid 
C) gibberellins and cytokinins 
D) cytokinins and ethylene 
E) abscisic acid and ethylene 
A) auxins and cytokinins 
B) auxins and abscisic acid 
C) gibberellins and cytokinins 
D) cytokinins and ethylene 
E) abscisic acid and ethylene

Question 11

-The figure above shows the cross section of a root grown under different conditions. Explain what is happening in picture B?

Accepted Answer

A) With no oxygen, the root has died. 
B) The root is infested with parasites that are eating the root. 
C) Root cells produce absicic acid to increase tolerance to low oxygen. 
D) Root cells produce cytokinins to promote movement of nutrients to roots. 
E) Low oxygen stimulates production of ethylene which causes apoptosis in some cells of the root cortex. 
A) With no oxygen, the root has died. 
B) The root is infested with parasites that are eating the root. 
C) Root cells produce absicic acid to increase tolerance to low oxygen. 
D) Root cells produce cytokinins to promote movement of nutrients to roots. 
E) Low oxygen stimulates production of ethylene which causes apoptosis in some cells of the root cortex.

Question 12

Most plants close their stomata at night. What colour of light would be most effective in promoting stomatal opening in the middle of the night?

Accepted Answer

A) red 
B) far-red 
C) blue 
D) red followed by far-red 
E) far-red followed by blue 
A) red 
B) far-red 
C) blue 
D) red followed by far-red 
E) far-red followed by blue

Question 13

A long-day plant will flower

Accepted Answer

A) in the late fall. 
B) when the night is shorter than a critical value. 
C) only under artificial light in the summer. 
D) during short days with proper fertilization. 
E) regardless of the photoperiod imposed. 
A) in the late fall. 
B) when the night is shorter than a critical value. 
C) only under artificial light in the summer. 
D) during short days with proper fertilization. 
E) regardless of the photoperiod imposed.

Question 14

A pathogenic fungus invades a plant. What does the infected plant produce in response to the attack?

Accepted Answer

A) antisense RNA 
B) phytoalexins 
C) phytochrome 
D) statoliths 
E) thickened cellulose microfibrils in the cell wall 
A) antisense RNA 
B) phytoalexins 
C) phytochrome 
D) statoliths 
E) thickened cellulose microfibrils in the cell wall

Question 15

A flash of red light followed by a flash of far-red light given during the middle of the night to a short-day plant will likely

Accepted Answer

A) cause increased flower production. 
B) have no effect upon flowering. 
C) inhibit flowering. 
D) stimulate flowering. 
E) convert florigen to the active form. 
A) cause increased flower production. 
B) have no effect upon flowering. 
C) inhibit flowering. 
D) stimulate flowering. 
E) convert florigen to the active form.

Question 16

Which of the following plant hormones would be found in very low amounts in a mature, water-stressed tomato plant?

Accepted Answer

A) auxins, abscisic acid, brassinosteroids 
B) auxins, gibberellins, cytokinins 
C) gibberellins, cytokinins, ethylene 
D) phytochrome, cytokinins, abscisic acid 
E) brassinosteroids, ethylene, phytochrome 
A) auxins, abscisic acid, brassinosteroids 
B) auxins, gibberellins, cytokinins 
C) gibberellins, cytokinins, ethylene 
D) phytochrome, cytokinins, abscisic acid 
E) brassinosteroids, ethylene, phytochrome

Question 17

If the range of a species of plants expands to a higher latitude, which of the following processes is the most likely to be modified by natural selection?

Accepted Answer

A) circadian rhythm 
B) photoperiodic response 
C) phototropic response 
D) biological clock 
E) thigmomorphogenesis 
A) circadian rhythm 
B) photoperiodic response 
C) phototropic response 
D) biological clock 
E) thigmomorphogenesis

Question 18

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

Accepted Answer

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

Question 19

Plants growing in a partially dark environment will grow toward light in a response called phototropism. Which of the following statements is true regarding phototropism?

Accepted Answer

A) It is caused by an electrical signal. 
B) One chemical involved is ethylene. 
C) Auxin causes a growth increase on one side of the stem. 
D) Auxin causes a decrease in growth on the side of the stem exposed to light. 
E) Removing the apical meristem enhances phototropism. 
A) It is caused by an electrical signal. 
B) One chemical involved is ethylene. 
C) Auxin causes a growth increase on one side of the stem. 
D) Auxin causes a decrease in growth on the side of the stem exposed to light. 
E) Removing the apical meristem enhances phototropism.

Question 20

Many plants flower in response to day-length cues. Which of the following statements best summarizes this phenomenon?

Accepted Answer

A) As a rule, short-day plants flower in the summer. 
B) As a rule, long-day plants flower in the spring or fall. 
C) Long-day plants flower in response to long days, not short nights. 
D) Flowering in day-neutral plants is only influenced by day length if there is an exceptionally warm spring. 
E) Flowering in short-day and long-day plants is controlled by phytochrome. 
A) As a rule, short-day plants flower in the summer. 
B) As a rule, long-day plants flower in the spring or fall. 
C) Long-day plants flower in response to long days, not short nights. 
D) Flowering in day-neutral plants is only influenced by day length if there is an exceptionally warm spring. 
E) Flowering in short-day and long-day plants is controlled by phytochrome.

Exam 39: Plant Responses to Internal and External Signals

Which of the following hormones would never be found in high concentrations in a dormant overwintering flower bud?

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

Which of the following statements is correct with regards to a "circadian rhythm" in plants?

How may a plant respond to severe heat stress?

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?

Gravitropism in plant shoots and roots differ in that

Which of the following plant hormones are most likely to act synergistically if expressed or applied to a drought-stricken plant?

The results of this experiment, shown on the left of the graph (area

Evidence for phototropism due to the asymmetric distribution of auxin moving down the stem

Which of the following plant hormones would most likely be found in high concentrations in a mature, slightly overripe fruit?

-The figure above shows the cross section of a root grown under different conditions. Explain what is happening in picture B?

Most plants close their stomata at night. What colour of light would be most effective in promoting stomatal opening in the middle of the night?

A long-day plant will flower

A pathogenic fungus invades a plant. What does the infected plant produce in response to the attack?

A flash of red light followed by a flash of far-red light given during the middle of the night to a short-day plant will likely

Which of the following plant hormones would be found in very low amounts in a mature, water-stressed tomato plant?

If the range of a species of plants expands to a higher latitude, which of the following processes is the most likely to be modified by natural selection?

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

Plants growing in a partially dark environment will grow toward light in a response called phototropism. Which of the following statements is true regarding phototropism?

Many plants flower in response to day-length cues. Which of the following statements best summarizes this phenomenon?

Introduction: Evolution and Themes of Biology

The Chemical Context of Life

Water and Life

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 and Fermentation

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

Regulation of Gene Expression

Viruses

Dna Tools and 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 Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure, Growth, and Development

Resource Acquisition and 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 Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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