Question 1

-What conclusion can you draw from the result in the question above.

Accepted Answer

A) As auxin concentration increases, lateral bud growth increases at a faster rate compared to the heavy line. 
B) As auxin concentration increases, lateral bud growth increases at a slower rate compared to the heavy line. 
C) The growth rate of lateral buds appears to be inhibited by higher auxin concentration. 
D) There is no relationship between lateral buds and auxin. 
E) More data is required before a conclusion can be drawn. 
A) As auxin concentration increases, lateral bud growth increases at a faster rate compared to the heavy line. 
B) As auxin concentration increases, lateral bud growth increases at a slower rate compared to the heavy line. 
C) The growth rate of lateral buds appears to be inhibited by higher auxin concentration. 
D) There is no relationship between lateral buds and auxin. 
E) More data is required before a conclusion can be drawn. C

Question 2

The aleurone layer is stimulated to release ________ and ________ as a result of giberrellin release from the embryo.

Accepted Answer

A) proteins; amino acids 
B) carbohydrates; sugars 
C) auxins; cytokinins 
D) amylase; protease 
E) RNAase; DNAase 
A) proteins; amino acids 
B) carbohydrates; sugars 
C) auxins; cytokinins 
D) amylase; protease 
E) RNAase; DNAase D

Question 3

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 E

Question 4

Charles and Francis Darwin concluded from their experiments on phototropism by grass seedlings that the part of the seedling that detects the direction of light is the

Accepted Answer

A) tip of the coleoptile. 
B) part of the coleoptile that bends during the response. 
C) base of the coleoptile. 
D) cotyledon. 
E) phytochrome in the leaves. 
A) tip of the coleoptile. 
B) part of the coleoptile that bends during the response. 
C) base of the coleoptile. 
D) cotyledon. 
E) phytochrome in the leaves.

Question 5

Plant cells begin synthesizing large quantities of heat-shock proteins

Accepted Answer

A) after the induction of chaperone proteins. 
B) in response to the lack of CO₂ following the closing of stomata by ethylene. 
C) when desert plants are quickly removed from high temperatures. 
D) when they are subjected to moist heat (steam)followed by electric shock. 
E) whenever the external temperature exceeds the threshold where photosynthesis is negatively impacted. 
A) after the induction of chaperone proteins. 
B) in response to the lack of CO₂ following the closing of stomata by ethylene. 
C) when desert plants are quickly removed from high temperatures. 
D) when they are subjected to moist heat (steam)followed by electric shock. 
E) whenever the external temperature exceeds the threshold where photosynthesis is negatively impacted.

Question 6

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

Accepted Answer

A) to destroy pathogens directly 
B) to activate systemic acquired resistance of plants 
C) to close stomata, thus preventing the entry of pathogens 
D) to activate heat-shock proteins 
E) to sacrifice infected tissues by hydrolyzing cells 
A) to destroy pathogens directly 
B) to activate systemic acquired resistance of plants 
C) to close stomata, thus preventing the entry of pathogens 
D) to activate heat-shock proteins 
E) to sacrifice infected tissues by hydrolyzing cells

Question 7

External stimuli would be received most quickly by a plant cell if the receptors for signal transduction were located in the

Accepted Answer

A) plasma membrane. 
B) cytoplasmic matrix. 
C) endoplasmic reticulum. 
D) nuclear membrane. 
E) nucleoplasm. 
A) plasma membrane. 
B) cytoplasmic matrix. 
C) endoplasmic reticulum. 
D) nuclear membrane. 
E) nucleoplasm.

Question 8

Charles and Francis Darwin discovered that

Accepted Answer

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

Question 9

Which of the following would only be activated or upregulated after a plant has already been infected by a pathogen?

Accepted Answer

A) phytochrome 
B) salicylic acid 
C) molecular chaperones 
D) stress proteins 
E) brassinosteroids 
A) phytochrome 
B) salicylic acid 
C) molecular chaperones 
D) stress proteins 
E) brassinosteroids

Question 10

Which of the following conclusions is supported by the research of 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. 
E) Light stimulates the synthesis of a plant hormone that responds to light. 
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. 
E) Light stimulates the synthesis of a plant hormone that responds to light.

Question 11

Ethylene differs from other plant hormones in that

Accepted Answer

A) it is produced in very small amounts. 
B) it is a gas. 
C) it has multiple effects. 
D) it is only produced in seedlings. 
E) it is transported in the xylem and phloem. 
A) it is produced in very small amounts. 
B) it is a gas. 
C) it has multiple effects. 
D) it is only produced in seedlings. 
E) it is transported in the xylem and phloem.

Question 12

Which plant hormones would likely be found in high amounts in a sprouting vegetative stem?

Accepted Answer

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

Question 13

If a long-day plant has a critical night length of 9 hours, which 24-hour cycle would prevent flowering?

Accepted Answer

A) 16 hours light/8 hours dark 
B) 14 hours light/10 hours dark 
C) 15.5 hours light/8.5 hours dark 
D) 4 hours light/8 hours dark/4 hours light/8 hours dark 
E) 8 hours light/8 hours dark/light flash/8 hours dark 
A) 16 hours light/8 hours dark 
B) 14 hours light/10 hours dark 
C) 15.5 hours light/8.5 hours dark 
D) 4 hours light/8 hours dark/4 hours light/8 hours dark 
E) 8 hours light/8 hours dark/light flash/8 hours dark

Question 14

According to modern ideas about phototropism in plants

Accepted Answer

A) light causes auxin to accumulate on the shaded side of a plant stem. 
B) auxin indirectly inhibits elongation of plant stem cells. 
C) auxin is produced by the apical meristem of the coleoptile and moves downward. 
D) all hormones move downward via the xylem. 
E) cytokinins are more directly involved than auxins. 
A) light causes auxin to accumulate on the shaded side of a plant stem. 
B) auxin indirectly inhibits elongation of plant stem cells. 
C) auxin is produced by the apical meristem of the coleoptile and moves downward. 
D) all hormones move downward via the xylem. 
E) cytokinins are more directly involved than auxins.

Question 15

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 16

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 17

-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 18

The biological clock controlling circadian rhythms must ultimately

Accepted Answer

A) depend on environmental cues. 
B) affect gene transcription. 
C) stabilize on a 24-hour cycle. 
D) speed up or slow down with increasing or decreasing temperature. 
E) do all of the above. 
A) depend on environmental cues. 
B) affect gene transcription. 
C) stabilize on a 24-hour cycle. 
D) speed up or slow down with increasing or decreasing temperature. 
E) do all of the above.

Question 19

Which of the following is a major mechanism whereby hormones control plant development?

Accepted Answer

A) cell respiration via regulation of the citric acid cycle 
B) cell division via the cell cycle 
C) cell elongation through production of cellulase 
D) cell differentiation through altered spliceosome activity 
E) cell synthesis of proteins via altered gene expression 
A) cell respiration via regulation of the citric acid cycle 
B) cell division via the cell cycle 
C) cell elongation through production of cellulase 
D) cell differentiation through altered spliceosome activity 
E) cell synthesis of proteins via altered gene expression

Question 20

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.

Exam 39: Plant Responses to Internal and External Signals

-What conclusion can you draw from the result in the question above.

The aleurone layer is stimulated to release ________ and ________ as a result of giberrellin release from the embryo.

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

Charles and Francis Darwin concluded from their experiments on phototropism by grass seedlings that the part of the seedling that detects the direction of light is the

Plant cells begin synthesizing large quantities of heat-shock proteins

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

External stimuli would be received most quickly by a plant cell if the receptors for signal transduction were located in the

Charles and Francis Darwin discovered that

Which of the following would only be activated or upregulated after a plant has already been infected by a pathogen?

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

Ethylene differs from other plant hormones in that

Which plant hormones would likely be found in high amounts in a sprouting vegetative stem?

If a long-day plant has a critical night length of 9 hours, which 24-hour cycle would prevent flowering?

According to modern ideas about phototropism in plants

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?

A plant seedling bends toward sunlight because

-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?

The biological clock controlling circadian rhythms must ultimately

Which of the following is a major mechanism whereby hormones control plant development?

Why do coleoptiles grow toward light?

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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The aleurone layer is stimulated to release and as a result of giberrellin release from the embryo.