Question 1

Given that Flagyl produces only minor side effects (if any)in humans, and given the set of parasites that it kills, Flagyl's mode of action probably involves

Accepted Answer

A)  peptidoglycan. 
B)  mitochondria or mitosomes. 
C)  anaerobic metabolic pathways. 
D)  nuclear envelopes. 
E)  microtubules. 
A)  peptidoglycan. 
B)  mitochondria or mitosomes. 
C)  anaerobic metabolic pathways. 
D)  nuclear envelopes. 
E)  microtubules.

Question 2

If we were to apply the most recent technique used to fight potato late blight to the fight against the malarial infection of humans, then we would

Accepted Answer

A)  increase the dosage of the least-expensive antimalarial drug administered to humans. 
B)  increase the dosage of the most common pesticide used to kill Anopheles mosquitoes. 
C)  introduce a predator of the malarial parasite into infected humans. 
D)  use a "cocktail" of at least three different pesticides against Anopheles mosquitoes. 
E)  insert genes from a Plasmodium-resistant strain of mosquito into Anopheles mosquitoes. 
A)  increase the dosage of the least-expensive antimalarial drug administered to humans. 
B)  increase the dosage of the most common pesticide used to kill Anopheles mosquitoes. 
C)  introduce a predator of the malarial parasite into infected humans. 
D)  use a "cocktail" of at least three different pesticides against Anopheles mosquitoes. 
E)  insert genes from a Plasmodium-resistant strain of mosquito into Anopheles mosquitoes.

Question 3

The next few questions refer to the following description and Table 28.1.
Diatoms are encased in Petri-platelike cases (valves) made of translucent hydrated silica whose thickness can be varied. The material used to store excess calories can also be varied. At certain times, diatoms store excess calories in the form of the liquid polysaccharide, laminarin, and at other times as oil. The following are data concerning the density (specific gravity) of various components of diatoms, and of their environment.
Table 28.1 Specific Gravities of Materials Relevant to Diatoms
  
-Using dead diatoms to "pump" CO₂ to the seafloor is feasible only if dead diatoms sink quickly. Consequently, application of mineral fertilizers, such as iron, should be most effective at times when diatom valves

Accepted Answer

A)  are thickest, and laminarin is being produced rather than oil. 
B)  are thickest, and oil is being produced rather than laminarin. 
C)  are thinnest, and laminarin is being produced rather than oil. 
D)  are thinnest, and oil is being produced rather than laminarin. 
A)  are thickest, and laminarin is being produced rather than oil. 
B)  are thickest, and oil is being produced rather than laminarin. 
C)  are thinnest, and laminarin is being produced rather than oil. 
D)  are thinnest, and oil is being produced rather than laminarin.

Question 4

Living diatoms contain brownish plastids. If global warming causes blooms of diatoms in the surface waters of Earth's oceans, how might this be harmful to the animals that build coral reefs?

Accepted Answer

A)  The coral animals, which capture planktonic organisms, may be outcompeted by the diatoms. 
B)  The coral animals' endosymbiotic dinoflagellates may get "shaded out" by the diatoms. 
C)  The coral animals may die from overeating the plentiful diatoms, with their cases of silica. 
D)  The diatoms' photosynthetic output may over-oxygenate the water. 
A)  The coral animals, which capture planktonic organisms, may be outcompeted by the diatoms. 
B)  The coral animals' endosymbiotic dinoflagellates may get "shaded out" by the diatoms. 
C)  The coral animals may die from overeating the plentiful diatoms, with their cases of silica. 
D)  The diatoms' photosynthetic output may over-oxygenate the water.

Question 5

The chloroplasts of all of the following are thought to be derived from ancestral red algae, except those of

Accepted Answer

A)  golden algae. 
B)  diatoms. 
C)  dinoflagellates. 
D)  green algae. 
E)  brown algae. 
A)  golden algae. 
B)  diatoms. 
C)  dinoflagellates. 
D)  green algae. 
E)  brown algae.

Question 6

Which of the following statements concerning protists is true?

Accepted Answer

A)  All protists have mitochondria, though in some species they are much reduced and known by different names. 
B)  The primary organism that transmits malaria to humans by its bite is the tsetse fly. 
C)  All apicomplexans are autotrophic. 
D)  All slime molds have an amoeboid stage that may be followed by a stage during which spores are produced. 
E)  Euglenozoans that are mixotrophic lack functional chloroplasts. 
A)  All protists have mitochondria, though in some species they are much reduced and known by different names. 
B)  The primary organism that transmits malaria to humans by its bite is the tsetse fly. 
C)  All apicomplexans are autotrophic. 
D)  All slime molds have an amoeboid stage that may be followed by a stage during which spores are produced. 
E)  Euglenozoans that are mixotrophic lack functional chloroplasts.

Question 7

The best evidence for not classifying the slime molds as fungi comes from slime molds'

Accepted Answer

A)  DNA sequences. 
B)  nutritional modes. 
C)  choice of habitats. 
D)  physical appearance. 
E)  reproductive methods. 
A)  DNA sequences. 
B)  nutritional modes. 
C)  choice of habitats. 
D)  physical appearance. 
E)  reproductive methods.

Question 8

The genome of modern chloroplasts is roughly 50% the size of the genome of the cyanobacterium from which it is thought to have been derived. In comparison, the genome of P. chromatophora's cyanelle is only slightly reduced relative to the size of the genome of the cyanobacterium from which it is thought to have been derived. What is a valid conclusion that can be drawn from this comparison?

Accepted Answer

A)  Lytic phage infections have targeted the chloroplast genome more often than the P. chromatophora genome. 
B)  P. chromatophora's cyanelle is the result of an evolutionarily recent endosymbiosis. 
C)  The genome of the chloroplast ancestor contained many more introns that could be lost without harm, compared to the cyanelle's genome. 
D)  All three of the conclusions above are valid. 
E)  Two of the conclusions above are valid. 
A)  Lytic phage infections have targeted the chloroplast genome more often than the P. chromatophora genome. 
B)  P. chromatophora's cyanelle is the result of an evolutionarily recent endosymbiosis. 
C)  The genome of the chloroplast ancestor contained many more introns that could be lost without harm, compared to the cyanelle's genome. 
D)  All three of the conclusions above are valid. 
E)  Two of the conclusions above are valid.

Question 9

If the mitosomes of Giardia contain no DNA, yet are descendants of what were once free-living organisms, then where are we likely to find the genes that encode their structures, and what accounts for their current location there?

Accepted Answer

A)  plasmids; conjugation 
B)  plasmids; transformation 
C)  nucleus; horizontal gene transfer 
D)  nucleus; S phase 
A)  plasmids; conjugation 
B)  plasmids; transformation 
C)  nucleus; horizontal gene transfer 
D)  nucleus; S phase

Question 10

Diplomonads, such as Giardia, contain two haploid nuclei per trophozoite. Thus, during the G₁ phase of the cell cycle, there should be a total of how many unreplicated chromosomes per trophozoite, and during the G₂ phase, how many replicated chromosomes per trophozoite?

Accepted Answer

A)  5; 5 
B)  5; 10 
C)  10; 10 
D)  10; 20 
E)  20; 20 
A)  5; 5 
B)  5; 10 
C)  10; 10 
D)  10; 20 
E)  20; 20

Question 11

Unlike most excavates, Giardia trophozoites have no oral groove and are unable to form food vacuoles. Thus, we should expect its nutrition (mostly glucose)to come from

Accepted Answer

A)  its mitosomes. 
B)  endosymbiotic cyanobacteria. 
C)  the ventral disk by which it adheres to the intestinal lining. 
D)  osmosis involving aquaporins. 
E)  plasma membrane proteins that are transporters or pumps. 
A)  its mitosomes. 
B)  endosymbiotic cyanobacteria. 
C)  the ventral disk by which it adheres to the intestinal lining. 
D)  osmosis involving aquaporins. 
E)  plasma membrane proteins that are transporters or pumps.

Question 12

Which protists are in the same eukaryotic supergroup as land plants?

Accepted Answer

A)  green algae 
B)  dinoflagellates 
C)  red algae 
D)  brown algae 
E)  both green algae and red algae 
A)  green algae 
B)  dinoflagellates 
C)  red algae 
D)  brown algae 
E)  both green algae and red algae

Question 13

In life cycles with an alternation of generations, multicellular haploid forms alternate with

Accepted Answer

A)  unicellular haploid forms. 
B)  unicellular diploid forms. 
C)  multicellular haploid forms. 
D)  multicellular diploid forms. 
E)  multicellular polyploid forms. 
A)  unicellular haploid forms. 
B)  unicellular diploid forms. 
C)  multicellular haploid forms. 
D)  multicellular diploid forms. 
E)  multicellular polyploid forms.

Question 14

Giardia lamblia is an intestinal parasite of humans and other mammals that causes intestinal ailments in most people who ingest the cysts. Upon ingestion, each cyst releases two motile cells, called trophozoites. These attach to the small intestine's lining via a ventral adhesive disk. The trophozoites anaerobically metabolize glucose from the host's intestinal contents to produce ATP. Reproduction is completely asexual, occurring by longitudinal binary fission of trophozoites, with each daughter cell receiving two, haploid nuclei (n = 5). A trophozoite will often encyst as it passes into the large intestine by secreting around itself a case that is resistant to cold, heat, and dehydration. Infection usually occurs by drinking untreated water that contains cysts.
-The trophozoites of Giardia were first observed in 1681 in the diarrhea stools of the first known person to view protists with a microscope, a person named

Accepted Answer

A)  Robert Koch. 
B)  Robert Hooke. 
C)  Isaac Newton. 
D)  van Leeuwenhoek. 
E)  Louis Pasteur. 
A)  Robert Koch. 
B)  Robert Hooke. 
C)  Isaac Newton. 
D)  van Leeuwenhoek. 
E)  Louis Pasteur.

Question 15

You are given an unknown organism to identify. It is unicellular and heterotrophic. It is motile, using many short extensions of the cytoplasm, each featuring the 9 + 2 filament pattern. It has well-developed organelles and three nuclei, one large and two small. This organism is most likely to be a member of which group?

Accepted Answer

A)  foraminiferans 
B)  radiolarians 
C)  ciliates 
D)  kinetoplastids 
E)  slime molds 
A)  foraminiferans 
B)  radiolarians 
C)  ciliates 
D)  kinetoplastids 
E)  slime molds

Question 16

Theoretically, P.bursaria can obtain zoochlorella either vertically (via the asexual reproduction of its mother cell)or horizontally (by ingesting free-living Chlorella from its habitat). Consider a P. bursaria cell containing zoochlorellae, but whose habitat lacks free-living Chlorella. If this cell subsequently undergoes many generations of asexual reproduction, if all of its daughter cells contain roughly the same number of zoochlorellae as it had originally contained, and if the zoochlorellae are all haploid and identical in appearance, then what is true?

Accepted Answer

A)  The zoochlorellae also reproduced asexually, at an increasing rate over time. 
B)  The zoochlorellae also reproduced asexually, at a decreasing rate over time. 
C)  The zoochlorellae also reproduced asexually, at a fairly constant rate over time. 
D)  The zoochlorellae reproduced sexually, undergoing heteromorphic alternation of generations. 
E)  The zoochlorellae reproduced sexually, undergoing isomorphic alternation of generations. 
A)  The zoochlorellae also reproduced asexually, at an increasing rate over time. 
B)  The zoochlorellae also reproduced asexually, at a decreasing rate over time. 
C)  The zoochlorellae also reproduced asexually, at a fairly constant rate over time. 
D)  The zoochlorellae reproduced sexually, undergoing heteromorphic alternation of generations. 
E)  The zoochlorellae reproduced sexually, undergoing isomorphic alternation of generations.

Question 17

The cysts of Giardia are most analogous to the

Accepted Answer

A)  mitochondria of ancestral diplomonads. 
B)  nuclei of archaeans. 
C)  endospores of bacteria. 
D)  capsids of viruses. 
A)  mitochondria of ancestral diplomonads. 
B)  nuclei of archaeans. 
C)  endospores of bacteria. 
D)  capsids of viruses.

Question 18

A P. bursaria cell that has lost its zoochlorellae is said to be aposymbiotic. It might be able to replenish its contingent of zoochlorellae by ingesting them without subsequently digesting them. Which of the following situations would be most favorable to the reestablishment of resident zoochlorellae, assuming compatible Chlorella are present in P. bursaria's habitat?

Accepted Answer

A)  abundant light, no bacterial prey 
B)  abundant light, abundant bacterial prey 
C)  no light, no bacterial prey 
D)  no light, abundant bacterial prey 
A)  abundant light, no bacterial prey 
B)  abundant light, abundant bacterial prey 
C)  no light, no bacterial prey 
D)  no light, abundant bacterial prey

Question 19

A snail-like, coiled, porous test (shell)of calcium carbonate is characteristic of which group?

Accepted Answer

A)  diatoms 
B)  foraminiferans 
C)  radiolarians 
D)  gymnamoebas 
A)  diatoms 
B)  foraminiferans 
C)  radiolarians 
D)  gymnamoebas

Question 20

If the Archaeplastidae are eventually designated a kingdom, and if land plants are excluded from this kingdom, then what will be true of this new kingdom?

Accepted Answer

A)  It will be monophyletic. 
B)  It will more accurately depict evolutionary relationships than does the current taxonomy. 
C)  It will be paraphyletic. 
D)  It will be a true clade. 
E)  It will be polyphyletic. 
A)  It will be monophyletic. 
B)  It will more accurately depict evolutionary relationships than does the current taxonomy. 
C)  It will be paraphyletic. 
D)  It will be a true clade. 
E)  It will be polyphyletic.

Exam 28: Protists

Given that Flagyl produces only minor side effects (if any)in humans, and given the set of parasites that it kills, Flagyl's mode of action probably involves

If we were to apply the most recent technique used to fight potato late blight to the fight against the malarial infection of humans, then we would

Living diatoms contain brownish plastids. If global warming causes blooms of diatoms in the surface waters of Earth's oceans, how might this be harmful to the animals that build coral reefs?

The chloroplasts of all of the following are thought to be derived from ancestral red algae, except those of

Which of the following statements concerning protists is true?

The best evidence for not classifying the slime molds as fungi comes from slime molds'

If the mitosomes of Giardia contain no DNA, yet are descendants of what were once free-living organisms, then where are we likely to find the genes that encode their structures, and what accounts for their current location there?

Diplomonads, such as Giardia, contain two haploid nuclei per trophozoite. Thus, during the G₁ phase of the cell cycle, there should be a total of how many unreplicated chromosomes per trophozoite, and during the G₂ phase, how many replicated chromosomes per trophozoite?

Unlike most excavates, Giardia trophozoites have no oral groove and are unable to form food vacuoles. Thus, we should expect its nutrition (mostly glucose)to come from

Which protists are in the same eukaryotic supergroup as land plants?

In life cycles with an alternation of generations, multicellular haploid forms alternate with

The cysts of Giardia are most analogous to the

A snail-like, coiled, porous test (shell)of calcium carbonate is characteristic of which group?

If the Archaeplastidae are eventually designated a kingdom, and if land plants are excluded from this kingdom, then what will be true of this new kingdom?

Introduction: Themes in the Study of Life

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

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

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

Plant Responses to Internal and External Signals

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 Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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