Question 1

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 2

Similar to other hormones,gibberellins affect plant development in several ways,except to

Accepted Answer

A) stimulate pollen tube growth. 
B) cause bolting. 
C) promote normal fruit growth. 
D) induce seed dormancy. 
E) stimulate stem and leaf growth. 
A) stimulate pollen tube growth. 
B) cause bolting. 
C) promote normal fruit growth. 
D) induce seed dormancy. 
E) stimulate stem and leaf growth.

Question 3

If you wanted to genetically engineer a plant to be more resistant to drought,increasing amounts of which of the following hormones might be a good first attempt?

Accepted Answer

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

Question 4

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 5

A particular species of virus carries a gene for salicylate hydroxylase,an enzyme that breaks down salicylic acid.Will this virus be more or less virulent to plants than other viruses?

Accepted Answer

A) more 
B) less 
C) This will not make the virus more or less virulent. 
A) more 
B) less 
C) This will not make the virus more or less virulent.

Question 6

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 7

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 8

Which of the following watering regimens will be most effective at keeping a lawn green during the hot,dry summer months?

Accepted Answer

A) daily sprinkling to soak the soil to 0.5 inch 
B) sprinkling every other day to soak the soil to 1.0 inch 
C) sprinkling every third day to soak the soil to 2.0 inches 
D) daily sprinkling to soak the soil to 0.5 inch or sprinkling every other day to soak the soil to 1.0 inch 
E) sprinkling every other day to soak the soil to 1.0 inch or sprinkling every third day to soak the soil to 2.0 inches 
A) daily sprinkling to soak the soil to 0.5 inch 
B) sprinkling every other day to soak the soil to 1.0 inch 
C) sprinkling every third day to soak the soil to 2.0 inches 
D) daily sprinkling to soak the soil to 0.5 inch or sprinkling every other day to soak the soil to 1.0 inch 
E) sprinkling every other day to soak the soil to 1.0 inch or sprinkling every third day to soak the soil to 2.0 inches

Question 9

Which of the following plant growth responses is primarily due to the action of auxins?

Accepted Answer

A) leaf abscission 
B) fruit development 
C) cell division 
D) the detection of photoperiod 
E) cell elongation 
A) leaf abscission 
B) fruit development 
C) cell division 
D) the detection of photoperiod 
E) cell elongation

Question 10

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

Question 11

The signalling molecule for flowering might be released earlier than usual in a long-day plant exposed to flashes of

Accepted Answer

A) far-red light during the night. 
B) red light during the night. 
C) red light followed by far-red light during the night. 
D) far-red light during the day. 
E) red light during the day. 
A) far-red light during the night. 
B) red light during the night. 
C) red light followed by far-red light during the night. 
D) far-red light during the day. 
E) red light during the day.

Question 12

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 13

The transduction pathway that activates systemic acquired resistance in plants is initially signalled 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 14

-The results of this experiment,shown on the left of the graph (area A),may be used to

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 15

-The heavy line in the above figure illustrates the relationship between auxin concentration and cell growth in stem tissues.If the same range of concentrations were applied to lateral buds,what curve(s)would probably be produced?

Accepted Answer

A) I 
B) II 
C) III 
D) II or III 
E) I or III 
A) I 
B) II 
C) III 
D) II or III 
E) I or III

Question 16

The following questions refer to the description below.
Plants are not able to move away from predators,so they have evolved chemical methods to protect themselves.Biologists have observed that caterpillars munching on a leaf can be attacked by certain species of wasps.These wasps lay their eggs inside the caterpillar's body,and when the eggs hatch,the larvae feed on its host from the inside.
-Wasps that are free-living but lay their eggs in another species,such as described above,are called

Accepted Answer

A) parasites. 
B) predators. 
C) parasitoids. 
D) competitors. 
E) insect pests. 
A) parasites. 
B) predators. 
C) parasitoids. 
D) competitors. 
E) insect pests.

Question 17

Which of the following statements applies to plant growth regulators?

Accepted Answer

A) They only act by altering gene expression. 
B) They often have a multiplicity of effects. 
C) They function independently of other hormones. 
D) They directly control plant protein synthesis and assembly. 
E) They affect the division and elongation, but not the differentiation, of cells. 
A) They only act by altering gene expression. 
B) They often have a multiplicity of effects. 
C) They function independently of other hormones. 
D) They directly control plant protein synthesis and assembly. 
E) They affect the division and elongation, but not the differentiation, of cells.

Question 18

Plant hormones can have different effects at different concentrations.This explains how

Accepted Answer

A) some plants are long-day plants and others are short-day plants. 
B) signal transduction pathways in plants are different from those in animals. 
C) plant genes recognize pathogen genes. 
D) auxin can stimulate cell elongation in apical meristems, yet will inhibit the growth of axillary buds. 
E) gibberellin concentration can both induce and break dormancy. 
A) some plants are long-day plants and others are short-day plants. 
B) signal transduction pathways in plants are different from those in animals. 
C) plant genes recognize pathogen genes. 
D) auxin can stimulate cell elongation in apical meristems, yet will inhibit the growth of axillary buds. 
E) gibberellin concentration can both induce and break dormancy.

Question 19

Vines in tropical rain forests must grow toward large trees before being able to grow toward the sun.To reach a large tree,the most useful kind of growth movement for a tropical vine presumably would be the opposite of

Accepted Answer

A) positive thigmotropism. 
B) positive phototropism. 
C) positive gravitropism. 
D) sleep movements. 
E) circadian rhythms. 
A) positive thigmotropism. 
B) positive phototropism. 
C) positive gravitropism. 
D) sleep movements. 
E) circadian rhythms.

Question 20

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

Exam 39: Plant Responses to Internal and External Signals

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

Similar to other hormones,gibberellins affect plant development in several ways,except to

If you wanted to genetically engineer a plant to be more resistant to drought,increasing amounts of which of the following hormones might be a good first attempt?

Why do coleoptiles grow toward light?

A particular species of virus carries a gene for salicylate hydroxylase,an enzyme that breaks down salicylic acid.Will this virus be more or less virulent to plants than other viruses?

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

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?

Which of the following watering regimens will be most effective at keeping a lawn green during the hot,dry summer months?

Which of the following plant growth responses is primarily due to the action of auxins?

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

The signalling molecule for flowering might be released earlier than usual in a long-day plant exposed to flashes of

Gravitropism in plant shoots and roots differ in that

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

-The results of this experiment,shown on the left of the graph (area A),may be used to

-The heavy line in the above figure illustrates the relationship between auxin concentration and cell growth in stem tissues.If the same range of concentrations were applied to lateral buds,what curve(s)would probably be produced?

Which of the following statements applies to plant growth regulators?

Plant hormones can have different effects at different concentrations.This explains how

Vines in tropical rain forests must grow toward large trees before being able to grow toward the sun.To reach a large tree,the most useful kind of growth movement for a tropical vine presumably would be the opposite of

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

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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