Question 1

Which one of the following hormones stimulates stem elongation and pollen tube growth?

Accepted Answer

A)  auxin (IA
A)  
B)  ethylene 
C)  gibberellins 
D)  cytokinins 
A)  auxin (IA
A)  
B)  ethylene 
C)  gibberellins 
D)  cytokinins

Question 2

Generally, each hormone has multiple functions in plants depending on ________.
I. site of action
II. its concentration
III. developmental stage
IV. age

Accepted Answer

A)  I, II, III, and IV 
B)  I, II, and III 
C)  I and II 
D)  II 
A)  I, II, III, and IV 
B)  I, II, and III 
C)  I and II 
D)  II

Question 3

Phytochrome plays a critical role in seed germination. Which of the colours maximises the seed germination?

Accepted Answer

A)  red 
B)  blue 
C)  violet 
D)  orange 
A)  red 
B)  blue 
C)  violet 
D)  orange

Question 4

Which of the following statements best summarises the acid growth hypothesis in an actively growing shoot?

Accepted Answer

A)  Auxin stimulates proton pumps in the plasma membrane and tonoplast. 
B)  Auxin-activated proton pumps lower the pH of the cell wall, which breaks bonds and makes the walls more flexible. 
C)  Auxins and gibberellins together act as a lubricant to help stretch cellulose microfibrils. 
D)  Auxins activate aquaporins that increase turgor pressure in the cells. 
A)  Auxin stimulates proton pumps in the plasma membrane and tonoplast. 
B)  Auxin-activated proton pumps lower the pH of the cell wall, which breaks bonds and makes the walls more flexible. 
C)  Auxins and gibberellins together act as a lubricant to help stretch cellulose microfibrils. 
D)  Auxins activate aquaporins that increase turgor pressure in the cells.

Question 5

Many plants flower in response to day-length cues. Which of the following statements best summarises 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 autumn. 
C)  Long-day plants flower in response to long days, not short nights. 
D)  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 autumn. 
C)  Long-day plants flower in response to long days, not short nights. 
D)  Flowering in short-day and long-day plants is controlled by phytochrome.

Question 6

You may have observed plants rotate towards a light source, thereby increasing the plant's ability to intercept light energy and increase photosynthesis. You, however, are given the task of preventing grass seedlings from rotating toward the light. Using your knowledge of phototropism, which of the following experimental procedures would you use to complete your task?

Accepted Answer

A)  Cover the growing tip of the grass seedling with black paper. 
B)  Supply the seedlings with very dim light (red light does not induce a bend). 
C)  Cover the portion of the seedling below the tip with a black shield. 
D)  Supply the seedling with nutrient-rich fertiliser solution. 
A)  Cover the growing tip of the grass seedling with black paper. 
B)  Supply the seedlings with very dim light (red light does not induce a bend). 
C)  Cover the portion of the seedling below the tip with a black shield. 
D)  Supply the seedling with nutrient-rich fertiliser solution.

Question 7

Who might be interested in using cytokinins?

Accepted Answer

A)  grocers, to spray on fruit to enhance ripening in the store 
B)  consumers, to spray on fruit before eating to enhance taste 
C)  florists, to dip stems in to keep leaves green longer 
D)  farmers, to spray on fruit after picking to stall ripening 
A)  grocers, to spray on fruit to enhance ripening in the store 
B)  consumers, to spray on fruit before eating to enhance taste 
C)  florists, to dip stems in to keep leaves green longer 
D)  farmers, to spray on fruit after picking to stall ripening

Question 8

Arrange the following steps that occur during drought tolerance in plants in a correct sequence.
I. hormone ABA accumulation in the leaves
II. causes stomata to close
III. reduction in transpiration
IV. preventing further water loss

Accepted Answer

A)  I, II, III, and IV 
B)  I, III, II, and IV 
C)  II, I, III, and IV 
D)  III, I, II, and IV 
A)  I, II, III, and IV 
B)  I, III, II, and IV 
C)  II, I, III, and IV 
D)  III, I, II, and IV

Question 9

Shoots that grow vertically toward the sun can be characterised as ________.

Accepted Answer

A)  positive for phototropism and negative for gravitropism 
B)  neutral for phototropism and positive for gravitropism 
C)  negative for phototropism and positive for gravitropism 
D)  positive for phototropism and neutral for gravitropism 
A)  positive for phototropism and negative for gravitropism 
B)  neutral for phototropism and positive for gravitropism 
C)  negative for phototropism and positive for gravitropism 
D)  positive for phototropism and neutral for gravitropism

Question 10

A plant mutant that shows normal gravitropic bending but does not store starch in its plastids would require a reevaluation of the role of ________ in gravitropism.

Accepted Answer

A)  auxin 
B)  calcium 
C)  statoliths 
D)  differential growth 
A)  auxin 
B)  calcium 
C)  statoliths 
D)  differential growth

Question 11

If a farmer wanted more loosely packed bunches of grapes, he would most likely spray the immature bunches with ________.

Accepted Answer

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

Question 12

Which of the following conclusions is supported by the research of both Peter Boysen-Jensen (1913) and Charles and Francis Darwin (late-1800s) on shoot responses to light?

Accepted Answer

A)  When shoots are exposed to light, a chemical substance migrates toward the light. 
B)  A chemical substance involved in shoot bending is produced in shoot tips. 
C)  Once shoot tips have been cut, normal growth cannot be induced. 
D)  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)  A chemical substance involved in shoot bending is produced in shoot tips. 
C)  Once shoot tips have been cut, normal growth cannot be induced. 
D)  Light stimulates the synthesis of a plant hormone that responds to light.

Question 13

Which of the colours of visible light induces curvature in coleoptile most effectively?

Accepted Answer

A)  red 
B)  blue 
C)  violet 
D)  orange 
A)  red 
B)  blue 
C)  violet 
D)  orange

Question 14

A population of plants experiences several years of severe drought. Much of the population dies due to lack of water, but a few individuals survive. You set out to discover the physiological basis for their adaptation to such an extreme environmental change. You hypothesise that the survivors have the ability to synthesise higher levels of ________ than their siblings do.

Accepted Answer

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

Question 15

The hormone that helps plants respond to drought is

Accepted Answer

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

Question 16

For a plant to initiate chemical responses to herbivory, before it is directly affected by herbivores, ________.

Accepted Answer

A)  a plant must have already flowered at least once 
B)  volatile "signal" compounds must be perceived 
C)  gene-for-gene intraspecific recognition must occur 
D)  phytoalexins must be released 
A)  a plant must have already flowered at least once 
B)  volatile "signal" compounds must be perceived 
C)  gene-for-gene intraspecific recognition must occur 
D)  phytoalexins must be released

Question 17

What are the primary sites of auxin (IAA) production in plants?

Accepted Answer

A)  shoot apical meristem and young leaves 
B)  roots 
C)  seeds 
D)  ripening fruits 
A)  shoot apical meristem and young leaves 
B)  roots 
C)  seeds 
D)  ripening fruits

Question 18

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. 
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.

Question 19

Which one of the following hormones regulates cell division in plants?

Accepted Answer

A)  auxin (IA
A)  
B)  ethylene 
C)  gibberellins 
D)  cytokinins 
A)  auxin (IA
A)  
B)  ethylene 
C)  gibberellins 
D)  cytokinins

Question 20

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 virulent 
B)  less virulent 
C)  same virulent 
D)  faster virulent 
A)  more virulent 
B)  less virulent 
C)  same virulent 
D)  faster virulent

Exam 39: Plant Responses to Internal and External Signals

Which one of the following hormones stimulates stem elongation and pollen tube growth?

Generally, each hormone has multiple functions in plants depending on ________. I. site of action II. its concentration III. developmental stage IV. age

Phytochrome plays a critical role in seed germination. Which of the colours maximises the seed germination?

Which of the following statements best summarises the acid growth hypothesis in an actively growing shoot?

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

Who might be interested in using cytokinins?

Arrange the following steps that occur during drought tolerance in plants in a correct sequence. I. hormone ABA accumulation in the leaves II. causes stomata to close III. reduction in transpiration IV. preventing further water loss

Shoots that grow vertically toward the sun can be characterised as ________.

A plant mutant that shows normal gravitropic bending but does not store starch in its plastids would require a reevaluation of the role of ________ in gravitropism.

If a farmer wanted more loosely packed bunches of grapes, he would most likely spray the immature bunches with ________.

Which of the following conclusions is supported by the research of both Peter Boysen-Jensen (1913) and Charles and Francis Darwin (late-1800s) on shoot responses to light?

Which of the colours of visible light induces curvature in coleoptile most effectively?

The hormone that helps plants respond to drought is

For a plant to initiate chemical responses to herbivory, before it is directly affected by herbivores, ________.

What are the primary sites of auxin (IAA) production in plants?

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

Which one of the following hormones regulates cell division in plants?

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?

Evolution, the Themes of Biology, and Scientific Inquiry

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

Gene Expression: 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 Colonised 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

Vascular 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

Filters