Question 1

In legumes,it has been shown that "sleep" (nastic)movements are correlated with

Accepted Answer

A) positive thigmotropisms. 
B) rhythmic opening and closing of K⁺ channels in motor cell membranes. 
C) senescence (the aging process in plants). 
D) flowering and fruit development. 
E) ABA-stimulated closing of guard cells caused by loss of K⁺. 
A) positive thigmotropisms. 
B) rhythmic opening and closing of K⁺ channels in motor cell membranes. 
C) senescence (the aging process in plants). 
D) flowering and fruit development. 
E) ABA-stimulated closing of guard cells caused by loss of K⁺.

Question 2

According to the acid growth hypothesis,auxin works by

Accepted Answer

A) dissolving sieve plates, permitting more rapid transport of nutrients. 
B) dissolving the cell membranes temporarily, permitting cells that were on the verge of dividing to divide more rapidly. 
C) changing the pH within the cell, which would permit the electron transport chain to operate more efficiently. 
D) increasing wall plasticity and allowing the affected cell walls to elongate. 
E) greatly increasing the rate of deposition of cell wall material. 
A) dissolving sieve plates, permitting more rapid transport of nutrients. 
B) dissolving the cell membranes temporarily, permitting cells that were on the verge of dividing to divide more rapidly. 
C) changing the pH within the cell, which would permit the electron transport chain to operate more efficiently. 
D) increasing wall plasticity and allowing the affected cell walls to elongate. 
E) greatly increasing the rate of deposition of cell wall material.

Question 3

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 4

What would happen if the secondary messenger cGMP was blocked in the de-etiolation pathway?

Accepted Answer

A) Specific protein kinase 1 would be activated, and greening would occur. 
B) Ca²⁺ channels would not open, and no greening would occur. 
C) Ca²⁺ channels could open, and specific protein kinase 2 could still be produced. 
D) No transcription of genes that function in de-etiolation would occur. 
E) Transcription of de-etiolation genes in the nucleus would not be affected. 
A) Specific protein kinase 1 would be activated, and greening would occur. 
B) Ca²⁺ channels would not open, and no greening would occur. 
C) Ca²⁺ channels could open, and specific protein kinase 2 could still be produced. 
D) No transcription of genes that function in de-etiolation would occur. 
E) Transcription of de-etiolation genes in the nucleus would not be affected.

Question 5

Experiments on the positive phototropic response of plants indicate that

Accepted Answer

A) light destroys auxin. 
B) auxin moves down the plant apoplastically. 
C) auxin is synthesized in the area where the stem bends. 
D) auxin can move to the shady side of the stem. 
E) auxin is only of secondary importance in the process. 
A) light destroys auxin. 
B) auxin moves down the plant apoplastically. 
C) auxin is synthesized in the area where the stem bends. 
D) auxin can move to the shady side of the stem. 
E) auxin is only of secondary importance in the process.

Question 6

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 7

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 8

The hormone that helps plants respond to drought is

Accepted Answer

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

Question 9

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.

Question 10

Which of the following is currently the most powerful method of research on plant hormones?

Accepted Answer

A) comparing photoperiodic responses 
B) comparing tropisms with turgor movements 
C) subjecting plants to various abiotic stresses 
D) studying plant/animal interactions 
E) analyzing mutant plants 
A) comparing photoperiodic responses 
B) comparing tropisms with turgor movements 
C) subjecting plants to various abiotic stresses 
D) studying plant/animal interactions 
E) analyzing mutant plants

Question 11

The initial response of the root cells of a tomato plant watered with sea water 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. 
E) actively absorb salts from the seawater. 
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. 
E) actively absorb salts from the seawater.

Question 12

Plant hormonal regulation differs from animal hormonal regulation in that

Accepted Answer

A) there are no dedicated hormone-producing organs in plants as there are in animals. 
B) all production of hormones is local in plants with little long-distance transport. 
C) only animal hormone concentrations are developmentally regulated. 
D) only animal hormones may have either external or internal receptors. 
A) there are no dedicated hormone-producing organs in plants as there are in animals. 
B) all production of hormones is local in plants with little long-distance transport. 
C) only animal hormone concentrations are developmentally regulated. 
D) only animal hormones may have either external or internal receptors.

Question 13

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. 
E) are correlated with moisture availability. 
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. 
E) are correlated with moisture availability.

Question 14

All of the following may function in signal transduction in plants except

Accepted Answer

A) calcium ions. 
B) nonrandom mutations. 
C) receptor proteins. 
D) phytochrome. 
E) secondary messengers. 
A) calcium ions. 
B) nonrandom mutations. 
C) receptor proteins. 
D) phytochrome. 
E) secondary messengers.

Question 15

Which of the following treatments would enhance the level of the Pfr form of phytochrome?

Accepted Answer

A) exposure to far-red light 
B) exposure to red light 
C) long dark period 
D) inhibition of protein synthesis 
E) synthesis of phosphorylating enzymes 
A) exposure to far-red light 
B) exposure to red light 
C) long dark period 
D) inhibition of protein synthesis 
E) synthesis of phosphorylating enzymes

Question 16

The plant hormone involved in aging and ripening of fruit is

Accepted Answer

A) auxin. 
B) ethylene. 
C) florigen. 
D) abscisic acid. 
E) gibberellin. 
A) auxin. 
B) ethylene. 
C) florigen. 
D) abscisic acid. 
E) gibberellin.

Question 17

A botanist discovers a plant that lacks the ability to form starch grains in root cells,yet the roots still grow downward.This evidence refutes the long-standing hypothesis that

Accepted Answer

A) falling statoliths trigger gravitropism. 
B) starch accumulation triggers the negative phototropic response of roots. 
C) starch grains block the acid growth response in roots. 
D) starch is converted to auxin, which causes the downward bending in roots. 
E) starch and downward movement are necessary for thigmotropism. 
A) falling statoliths trigger gravitropism. 
B) starch accumulation triggers the negative phototropic response of roots. 
C) starch grains block the acid growth response in roots. 
D) starch is converted to auxin, which causes the downward bending in roots. 
E) starch and downward movement are necessary for thigmotropism.

Question 18

Bald cypress and loblolly pine are both gymnosperm trees native to the southern United States.The cypress grows in swamps; the pine grows in sandy soil.How do you think their anatomies differ?

Accepted Answer

A) There are larger intercellular spaces in the roots of the cypress than in the roots of the pine. 
B) Water-conducting cells are larger in the stems of the cypress than in the stems of the pine. 
C) The springwood and summerwood are more distinct in the cypress. 
D) There is less parenchyma in the roots of the cypress than in the pine roots. 
E) There are no major anatomical differences between these species because they are both gymnosperms. 
A) There are larger intercellular spaces in the roots of the cypress than in the roots of the pine. 
B) Water-conducting cells are larger in the stems of the cypress than in the stems of the pine. 
C) The springwood and summerwood are more distinct in the cypress. 
D) There is less parenchyma in the roots of the cypress than in the pine roots. 
E) There are no major anatomical differences between these species because they are both gymnosperms.

Question 19

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

Accepted Answer

A) potassium channels. 
B) nervous tissue. 
C) aquaporins. 
D) stress proteins. 
A) potassium channels. 
B) nervous tissue. 
C) aquaporins. 
D) stress proteins.

Question 20

In extremely cold regions,woody species may survive freezing temperatures by

Accepted Answer

A) emptying water from the vacuoles to prevent freezing. 
B) decreasing the numbers of phospholipids in cell membranes. 
C) decreasing the fluidity of all cellular membranes. 
D) producing canavanine as a natural antifreeze. 
E) increasing cytoplasmic levels of specific solute concentrations, such as sugars. 
A) emptying water from the vacuoles to prevent freezing. 
B) decreasing the numbers of phospholipids in cell membranes. 
C) decreasing the fluidity of all cellular membranes. 
D) producing canavanine as a natural antifreeze. 
E) increasing cytoplasmic levels of specific solute concentrations, such as sugars.

Exam 39: Plant Responses to Internal and External Signals

In legumes,it has been shown that "sleep" (nastic)movements are correlated with

According to the acid growth hypothesis,auxin works by

Ethylene differs from other plant hormones in that

What would happen if the secondary messenger cGMP was blocked in the de-etiolation pathway?

Experiments on the positive phototropic response of plants indicate that

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

Charles and Francis Darwin discovered that

The hormone that helps plants respond to drought is

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

Which of the following is currently the most powerful method of research on plant hormones?

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

Plant hormonal regulation differs from animal hormonal regulation in that

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

All of the following may function in signal transduction in plants except

Which of the following treatments would enhance the level of the Pfr form of phytochrome?

The plant hormone involved in aging and ripening of fruit is

A botanist discovers a plant that lacks the ability to form starch grains in root cells,yet the roots still grow downward.This evidence refutes the long-standing hypothesis that

Bald cypress and loblolly pine are both gymnosperm trees native to the southern United States.The cypress grows in swamps; the pine grows in sandy soil.How do you think their anatomies differ?

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

In extremely cold regions,woody species may survive freezing temperatures by

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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