Unit 7 Taxonomy, Prokaryotes, & Simple Eukaryotes

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Unit 7 Taxonomy, Prokaryotes, & Simple Eukaryotes


Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 

Which gas was probably least abundant in Earth's early atmosphere?
a.
O2
b.
CO
c.
CH4
d.
H2O
e.
NH3
 

 2. 

Which putative early Earth condition did Miller and Urey's experimental apparatus not attempt to simulate directly?
a.
presence of water vapor
b.
intense lightning storms
c.
warm seas
d.
intense UV bombardment
e.
reducing atmosphere
 

 3. 

Which of the factors below weaken the hypothesis of abiotic synthesis of organic monomers in early Earth's atmosphere?
1. the relatively short time between intense meteor bombardment and appearance of the first life forms
2. the lack of experimental evidence that organic monomers can form by abiotic synthesis
3. uncertainty about which gases comprised early Earth's atmosphere
a.
1
b.
2
c.
3
d.
1 and 3
e.
2 and 3
 

 4. 

The early atmosphere of Earth probably retained all of the following molecules in substantial amounts except
a.
H2.
b.
CH4.
c.
CO2.
d.
N2.
e.
H2O.
 

 5. 

Which of the following has not yet been synthesized in laboratory experiments studying the origin of life?
a.
liposomes
b.
liposomes with selectively permeable membranes
c.
oligopeptides and other oligomers
d.
protobionts that use DNA to program protein synthesis
e.
amino acids
 

 6. 

What condition would have made the primitive atmosphere of Earth more conducive to the origin of life than the present one? The primitive atmosphere
a.
had a layer of ozone that shielded the first fragile cells.
b.
removed electrons that impeded the formation of protobionts.
c.
may have been a reducing one that facilitated the formation of complex substances from simple molecules.
d.
had more oxygen than the modern atmosphere, and thus it successfully sustained the first living organisms.
e.
had less free energy than the modern atmosphere, and thus newly formed organisms were less likely to be destroyed.
 

 7. 

What is true of the amino acids delivered to Earth within carbonaceous chondrites?
a.
They have the same proportion of L and D isomers as Earth does today.
b.
The proportion of the amino acids are similar to those produced in the Miller-Urey experiment.
c.
There were fewer kinds of amino acids on the chondrites than are found in living organisms today.
d.
They were delivered in the form of polypeptides.
e.
Upon entry into Earth's oxidizing atmosphere, most were destroyed.
 

 8. 

Which of the following is the correct sequence of these events in the origin of life?

I. Formation of protobionts
II. Synthesis of organic monomers
III. Synthesis of organic polymers
a.
I, II, III
b.
I, III, II
c.
II, III, I
d.
III, I, II
e.
III, II, I
 

 9. 

What characteristic would all protobionts have had in common?
a.
the ability to synthesize enzymes
b.
a surrounding membrane or membrane-like structure
c.
RNA genes
d.
a nucleus
e.
the ability to replicate RNA
 

 10. 

Although absolute distinctions between the "most evolved" protobiont and the first living cell are unclear, biologists generally agree that one major difference is that protobionts could not
a.
possess a selectively permeable membrane boundary.
b.
perform osmosis.
c.
grow in size.
d.
perform controlled, precise reproduction.
e.
absorb compounds from the external environment.
 

 11. 

Which of the following statements about the origin of genetic material is most probably correct? The first genes were
a.
DNA produced by reverse transcriptase from abiotically produced RNA.
b.
DNA molecules whose information was transcribed to RNA and later translated in polypeptides.
c.
self-replicating, catalytic RNA molecules.
d.
RNA produced by autocatalytic, proteinaceous enzymes called ribozymes.
e.
protobionts produced by dehydration syntheses of nucleic acids.
 

 12. 

RNA molecules can be both self-replicating and catalytic. This probably means that
a.
RNA was the first hereditary information.
b.
protobionts had an RNA membrane.
c.
RNA could make energy.
d.
free nucleotides would not have been necessary ingredients in the synthesis of new RNA molecules.
e.
RNA is a polymer of amino acids.
 

 13. 

What probably accounts for the switch to DNA-based genetic systems during the evolution of life on Earth?
a.
DNA is chemically more stable and replicates with fewer errors (mutations) than RNA.
b.
Only DNA can replicate during cell division.
c.
RNA is too involved with translation of proteins and cannot provide multiple functions.
d.
DNA forms the rod-shaped chromosomes necessary for cell division.
e.
Replication of RNA occurs too quickly.
 

 14. 

If the half-life of carbon-14 is about 5,730 years, then a fossil that has one-eighth the normal proportion of carbon-14 to carbon-12 is probably ____ years old.
a.
1,400
b.
2,800
c.
11,200
d.
16,800
e.
22,400
 

 15. 

Which measurement would help determine absolute dates by radiometric means?
a.
the accumulation of the daughter isotope
b.
the loss of parent isotopes
c.
the loss of daughter isotopes
d.
all three of these
e.
only A and B
 

 16. 

How many half-lives should have elapsed if 12.5% of the parent isotope remains in a fossil at the time of analysis?
a.
one
b.
two
c.
three
d.
four
e.
five
 

 17. 

Approximately how far back in time does the fossil record extend?
a.
6,000 years
b.
3,500,000 years
c.
6,000,000 years
d.
3,500,000,000 years
e.
5,000,000,000,000 years
 

 18. 

What was the consequence of the release of oxygen gas by plant and bacterial photosynthesis? It
a.
made life on land difficult for aerobic organisms.
b.
changed the atmosphere from oxidizing to reducing.
c.
made it easier to maintain reduced molecules.
d.
made Earth an oxidizing environment.
e.
prevented the formation of an ozone layer.
 

 19. 

Arrange these events from earliest to most recent.
1.      emission of lava in what is now Siberia at time of Permian extinctions
2.      emission of lava that solidified at the same time as iron-bearing terrestrial rocks began to rust
3.      emission of lava that solidified at the same time as the first banded iron formations formed
4.      emission of lava in what is now India at time of Cretaceous extinctions
a.
3, 1, 2, 4
b.
3, 2, 1, 4
c.
3, 1, 4, 2
d.
1, 3, 2, 4
e.
1, 2, 3, 4
 

 20. 

Elemental sulfur is to hydrogen-sulfide-splitting prokaryotes as ____ is to water-splitting prokaryotes.
a.
H+
b.
H2
c.
OH-
d.
O2
e.
H2O
 

 21. 

All are true of the photosynthetic machinery of cyanobacteria, except
a.
it involved a modified version of electron transport.
b.
it was assembled from two anaerobic systems that had originated in different types of bacteria.
c.
it evolved relatively late in the evolution of prokaryotes, sometime after eukaryotes had arisen.
d.
it obtains electrons by splitting water.
e.
it caused Earth's atmosphere to become an oxidizing one.
 

 22. 

At the time when Earth's atmosphere was becoming increasingly oxidizing, which reaction could have helped to prevent damage to oxygen-sensitive enzymes and structures. In which prokaryotes might such a reaction have been expected to occur? (Note: these reactions are not balanced.)
a.
e- + H+ + O2 H2O, alpha proteobacteria
b.
e- + H+ + S H2S, non-purple sulfur bactria
c.
e- + H+ + CO2 H2CO3, obligate anaerobes
d.
H2O e- + H+ + O2, cyanobacteria
e.
H2S e- + H+ + S, purple sulfur bacteria
 

 23. 

Which of the following statements provides the strongest evidence that prokaryotes evolved before eukaryotes?
a.
the primitive structure of plants
b.
meteorites that have struck Earth
c.
abiotic laboratory experiments that produced liposomes
d.
Liposomes resemble prokaryotic cells.
e.
The oldest fossilized cells resemble prokaryotes.
 

 24. 

How would the chief hypothesis concerning the origin of the ER and Golgi apparatus be described?
a.
endosymbiosis
b.
serial endosymbiosis
c.
genetic annealing
d.
infolding of the plasma membrane
e.
outfolding of the nuclear lamina
 

 25. 

Which is an actual observation that provides the strongest evidence for the possible origin of the eukaryotic cytoskeleton?
a.
Prokaryotic flagella possess microtubules in the 9 + 2 pattern.
b.
Only certain bacteria possess flagella.
c.
Homologs of actin and tubulin are found in certain bacteria.
d.
There is a lamina located within prokaryotic nuclei.
e.
The flagella of prokaryotes are hollow, like the microtubules of eukaryotic flagella.
 

 26. 

The photosystems of cyanobacteria are embedded in plasma membranes and, in some cases, in internal membranes derived from the plasma membrane. Where would one expect to find the homologous photosystems in green plant cells?
a.
plasma membrane
b.
outer membrane of chloroplasts
c.
inner compartments (stroma) of chloroplasts
d.
inner membranes of chloroplasts
e.
the membranes of other organelles (amyloplasts and tonoplasts)
 

 27. 

The ATP synthase of most mitochondria
a.
consists of protein subunits synthesized by ribosomes within the mitochondria.
b.
consists of protein subunits synthesized by ribosomes in the surrounding cytoplasm.
c.
is a component of a metabolic process that requires oxygen as a final electron acceptor.
d.
both A and C
e.
A, B, and C
 

 28. 

The hypothesis of "genetic annealing" is used to account for the origin of
a.
double-stranded DNA.
b.
the mitochondrial genome.
c.
the processes of mitosis and meiosis.
d.
the nuclear genome.
e.
DNA ligases.
 

 29. 

Which process is most directly associated with genetic annealing?
a.
binary fission
b.
horizontal gene transfer
c.
mitosis
d.
meiosis
e.
membrane invagination
 

 30. 

Which genetic process requires one cell or structure to lose genetic material to another cell or structure to which it was not previously genetically identical?

1. binary fission
2. mitosis
3. bacterial conjugation
4. horizontal gene transfer
a.
1 only
b.
3 only
c.
1 and 2
d.
1 and 3
e.
3 and 4
 

 31. 

What is the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth?

1. origin of mitochondria
2. origin of multicellular eukaryotes
3. origin of chloroplasts
4. origin of cyanobacteria
5. origin of fungal-plant symbioses
a.
4, 3, 2, 1, 5
b.
4, 1, 2, 3, 5
c.
4, 1, 3, 2, 5
d.
4, 3, 1, 5, 2
e.
3, 4, 1, 2, 5
 

 32. 

Recent evidence indicates that the first major diversification of multicellular eukaryotes may have coincided in time with the
a.
origin of prokaryotes.
b.
switch to an oxidizing atmosphere.
c.
melting that ended the "snowball Earth" period.
d.
origin of multicellular organisms.
e.
massive eruptions of deep-sea vents.
 

 33. 

Which event may be associated in time with the end of the period known as snowball Earth?
a.
oxygenation of Earth's seas and atmosphere
b.
evolution of mitochondria
c.
Cambrian explosion
d.
evolution of true multicellularity
e.
Permian extinction
 

 34. 

Assuming total ice cover, which of these would have been the most likely location for the oxygenic photosynthesizers to have survived snowball Earth?
a.
deep-sea vents
b.
shallow alpine "lakes"
c.
at mid-depth in oceans
d.
at depth, distant from deep-sea vents
e.
in close association with oceanic ice flows
 

 35. 

In order for a beneficial mutation to be transmitted across generations, the mutation must occur in
a.
a zygote.
b.
a sperm cell.
c.
an egg cell.
d.
a mother cell about to undergo meiosis.
e.
any of the above.
 

 36. 

The snowball Earth hypothesis provides a possible explanation for the
a.
diversification of animals at the start of the late Proterozoic.
b.
oxygenation of Earth's seas and atmosphere.
c.
colonization of land by plants and fungi.
d.
origin of O2-releasing photosynthesis.
e.
existence of hydrothermal vents on the ocean floor.
 

 37. 

If two continental land masses converge and are united during continental drift, then the collision should bring about
a.
a net loss of intertidal zone and coastal habitat.
b.
the extinction of species adapted to intertidal and coastal habitats.
c.
an overall increase in the surface area located in the continental interior.
d.
an increase in climatic extremes in the interior of the new supercontinent.
e.
all of the above
 

 38. 

A major evolutionary episode that corresponded in time most closely with the formation of Pangaea was the
a.
origin of humans.
b.
Cambrian explosion.
c.
Permian extinctions.
d.
Pleistocene ice ages.
e.
Cretaceous extinctions.
 

 39. 

What important criterion was used in the late 1960s to distinguish between the three multicellular eukaryotic kingdoms of the five-kingdom classification system?
a.
the number of cells present in individual organisms
b.
the geological stratum in which fossils first appear
c.
the nutritional modes they employ
d.
the biogeographic province where each first appears
e.
the features of their embryos
 

 40. 

As the number of kingdoms increased from two to three, what was true of the kingdom Protista?
a.
It was used to harbor all prokaryotes.
b.
All photosynthetic organisms were assigned to it.
c.
Viruses were assigned to this kingdom.
d.
Unicellular organisms of all kinds were placed here.
e.
It was used for organisms that did not fit clearly into the other two kingdoms.
 

 41. 

The best classification system is that which most closely
a.
unites organisms that possess similar morphologies.
b.
conforms to traditional, Linnaean taxonomic practices.
c.
reflects evolutionary history.
d.
corroborates the classification scheme in use at the time of Charles Darwin.
e.
reflects the basic separation of prokaryotes from eukaryotes.
 
 
The following questions refer to the list below, which uses the five-kingdom classification system.

1. Plantae
2. Fungi
3. Animalia
4. Protista
5. Monera
 

 42. 

Which obsolete kingdom includes prokaryotic organisms?
a.
1
b.
2
c.
3
d.
4
e.
5
 

 43. 

Members of which kingdom have cell walls and are all heterotrophic?
a.
1
b.
2
c.
3
d.
4
e.
5
 

 44. 

Which kingdom has been replaced with two domains?
a.
1
b.
2
c.
3
d.
4
e.
5
 
 
Match the scientists below with their accomplishments.

A. Carl Woese
B. Cech and Altman
C. Oparin and Haldane
D. Miller and Urey
E. Robert Whittaker
 

 45. 

discovered ribozymes
a.
A
b.
B
c.
C
d.
D
e.
E
 

 46. 

used SSU-rRNA sequences to propose major modifications to the "tree of life"
a.
A
b.
B
c.
C
d.
D
e.
E
 

 47. 

synthesized organic monomers in an apparatus designed to simulate early Earth's conditions
a.
A
b.
B
c.
C
d.
D
e.
E
 

 48. 

proposed the five-kingdom classification system
a.
A
b.
B
c.
C
d.
D
e.
E
 

 49. 

Which of the following statements about bacterial cell walls is false?
a.
Bacterial cell walls differ in molecular composition from plant cell walls.
b.
Cell walls prevent cells from bursting in hypotonic environments.
c.
Cell walls prevent cells from dying in hypertonic conditions.
d.
Bacterial cell walls are similar in function to the cell walls of many protists, fungi, and plants.
e.
Cell walls provide the cell with a degree of physical protection from the environment.
 

 50. 

Which of the following is the most common compound in the cell walls of gram-positive bacteria?
a.
cellulose
b.
lipopolysaccharide
c.
lignin
d.
peptidoglycan
e.
protein
 

 51. 

If penicillin is an antibiotic that inhibits enzymes from catalyzing the synthesis of peptidoglycan, then which prokaryotes should be most vulnerable to inhibition by penicillin?
a.
mycoplasmas
b.
gram-positive bacteria
c.
archaea
d.
gram-negative bacteria
e.
spore-bearing bacteria
 

 52. 

Which of the following is the correct order, from most external to most internal?

1. cell wall
2. plasma membrane
3. capsule
a.
1, 2, 3
b.
1, 3, 2
c.
2, 1, 3
d.
3, 2, 1
e.
3, 1, 2
 

 53. 

Jams, jellies, preserves, honey, and other foodstuffs with a high sugar content hardly ever become contaminated by bacteria, even when the food containers are left open at room temperature. This is because bacteria that encounter such an environment
a.
undergo death by plasmolysis.
b.
are unable to metabolize the glucose or fructose, and thus starve to death.
c.
undergo death by lysis.
d.
are obligate anaerobes.
e.
are unable to swim through these thick and viscous materials.
 

 54. 

In a bacterium that possesses antibiotic resistance and the potential to persist through very adverse conditions, such as freezing, drying, or high temperatures, DNA should be located within, or be part of, which structures?

1. nucleoid region
2. flagellum
3. endospore
4. fimbriae
5. plasmids
a.
1 only
b.
1 and 4
c.
1 and 5
d.
1, 3, and 5
e.
2, 4, and 5
 

 55. 

Which two structures play direct roles in permitting bacteria to adhere to each other, or to other surfaces?

1. capsules
2. endospores
3. fimbriae
4. plasmids
5. flagella
a.
1 and 2
b.
1 and 3
c.
2 and 3
d.
3 and 4
e.
3 and 5
 

 56. 

Prokaryotes have ribosomes different from those of eukaryotes. Because of this, which of the following is true?
a.
Some selective antibiotics can block protein synthesis of bacteria without harming the eukaryotic host.
b.
Eukaryotes did not evolve from prokaryotes.
c.
Translation can occur at the same time as transcription in eukaryotes but not in prokaryotes.
d.
Some antibiotics can block the formation of cross-links in the peptidoglycan walls of bacteria.
e.
Prokaryotes are able to use a much greater variety of molecules as food sources than can eukaryotes.
 

 57. 

Which of the following is a correct statement about the genomes of prokaryotes?
a.
Prokaryotic genomes are diploid throughout most of the cell cycle.
b.
Prokaryotic chromosomes are sometimes called "genochromes."
c.
Prokaryotic cells have multiple chromosomes packaged with a relatively large amount of protein.
d.
Prokaryotic chromosomes are not contained within a nucleus but, rather, are found at the nucleoid region.
e.
Prokaryotic genomes are composed of linear DNA (that is, DNA existing in the form of a line with two ends).
 

 58. 

If a bacterium regenerates from an endospore that does not have all of the plasmids contained in its parent cell, it will probably
a.
lack "contingency" functions.
b.
lack a cell wall.
c.
lack a chromosome.
d.
gain extra base pairs on its chromosome.
e.
be unable to survive in its normal environment.
 

 59. 

In regard to prokaryotic reproduction, which of the following is true?
a.
Prokaryotes form gametes by meiosis.
b.
Prokaryotes feature the union of haploid gametes, as do eukaryotes.
c.
Prokaryotes exchange some of their genes by conjugation, the union of haploid gametes, and transduction.
d.
Mutation is a primary source of variation in prokaryote populations.
e.
Prokaryotes skip sexual life cycles because their life cycle is too short.
 

 60. 

Which of the following statements about prokaryotes is correct?
a.
Bacterial cells conjugate to mutually exchange genetic material.
b.
Their genetic material is confined within a nuclear envelope.
c.
They divide by binary fission, without mitosis or meiosis.
d.
The persistence of bacteria throughout evolutionary time is due to genetic similarity.
e.
Genetic variation in bacteria is not known to occur, nor should it occur, because of their asexual mode of reproduction.
 
 
The following questions refer to structures found in a gram-positive prokaryotic cell. Answers (A-E) may be used once, more than once or not at all.

A. endospore
B. sex pilus
C. flagellum
D. cell wall
E. capsule
 

 61. 

composed almost entirely of peptidoglycan
a.
A
b.
B
c.
C
d.
D
e.
E
 

 62. 

requires ATP to function, and permits some species to respond to taxes.
a.
A
b.
B
c.
C
d.
D
e.
E
 

 63. 

Not present in all bacteria, this structure enables those that possess it to germinate after exposure to harsh conditions, such as boiling.
a.
A
b.
B
c.
C
d.
D
e.
E
 

 64. 

structure that permits conjugation to occur
a.
A
b.
B
c.
C
d.
D
e.
E
 

 65. 

an important source of endotoxin in gram-negative species
a.
A
b.
B
c.
C
d.
D
e.
E
 
 
Match the numbered terms below to the following descriptions. Choose all appropriate terms, but only appropriate terms.

1. autotroph
2. heterotroph
3. phototroph
4. chemotroph
 

 66. 

an organism that obtains its energy from chemicals
a.
1 only
b.
2 only
c.
3 only
d.
4 only
e.
1 and 4
 

 67. 

a prokaryote that obtains both energy and carbon as it decomposes dead organisms
a.
1 only
b.
4 only
c.
1 and 3
d.
2 and 4
e.
1, 3, and 4
 

 68. 

an organism that relies on photons to excite electrons within its membranes
a.
1 only
b.
3 only
c.
1 and 3
d.
2 and 4
e.
1, 3, and 4
 
 
Use the list below of types of bacterial metabolism to answer the following questions. Pick the term that best matches the statement. Responses may be used once, more than once, or not at all.

A. photoautotrophs
B. photoheterotrophs
C. chemoautotrophs
D. chemoheterotrophs that perform decomposition
E. parasitic chemoheterotrophs
 

 69. 

responsible for many human diseases
a.
A
b.
B
c.
C
d.
D
e.
E
 

 70. 

cyanobacteria
a.
A
b.
B
c.
C
d.
D
e.
E
 

 71. 

use light energy to synthesize organic compounds from CO2
a.
A
b.
B
c.
C
d.
D
e.
E
 

 72. 

use light energy to generate ATP but do not release oxygen
a.
A
b.
B
c.
C
d.
D
e.
E
 

 73. 

responsible for high levels of O2 in Earth's atmosphere
a.
A
b.
B
c.
C
d.
D
e.
E
 

 74. 

Modern mitochondria are the descendants of what were once free-living alpha proteobacteria. Insofar as mitochondria become inactive during periods of oxygen debt, what is probably true of their alpha proteobacterial ancestors?
a.
They were obligate aerobes and heterotrophs.
b.
They were obligate aerobes and autotrophs.
c.
They were obligate anaerobes and heterotrophs.
d.
They were obligate anaerobes and autotrophs.
e.
They were facultative anaerobes and autotrophs.
 

 75. 

Given that the enzymes that catalyze nitrogen fixation are poisoned by oxygen, what are two "strategies" that nitrogen-fixing prokaryotes might use to protect these enzymes from oxygen?

1. couple them with photosystem II
2. sequester them in gas-impermeable membranes
3. be obligate anaerobes
4. be strict aerobes
5. sequester these enzymes in specialized cells or compartments that inhibit oxygen entry
a.
1 and 4
b.
2 and 4
c.
2 and 5
d.
3 and 4
e.
3 and 5
 

 76. 

Carl Woese of the University of Illinois and his collaborators identified two major branches of prokaryotic evolution. What was the basis for dividing prokaryotes into two domains?
a.
microscopic examination of staining characteristics of the cell wall
b.
metabolic characteristics such as the production of methane gas
c.
metabolic characteristics such as chemoautotrophy and photosynthesis
d.
molecular characteristics such as ribosomal RNA sequences
e.
ecological characteristics such as the ability to survive in extreme environments
 

 77. 

Prokaryotic organisms have recently been divided into two domains, Bacteria and Archaea. This division is based on characteristics such as
a.
differences in cell wall composition.
b.
differences in their initiator amino acid for start of protein synthesis.
c.
presence or absence of histones.
d.
B and C only
e.
A, B, and C
 

 78. 

If archaea are more closely related to eukaryotes than to bacteria, then which of the following is a reasonable proposal?
a.
Archaean DNA should have no introns.
b.
Archaean chromosomes should have no protein bonded to them.
c.
Archaean DNA should be single-stranded.
d.
Archaean ribosomes should be larger than typical prokaryotic ribosomes.
e.
Archaea should lack cell walls.
 

 79. 

Which of the following traits do archaea and bacteria share?

1. composition of the cell wall
2. presence of plasma membrane
3. lack of a nuclear envelope
4. identical rRNA sequences
a.
1 only
b.
3 only
c.
1 and 3
d.
2 and 3
e.
2 and 4
 

 80. 

In general, it should take the least amount of time to sequence the entire genome of a typical member of
a.
Bacteria.
b.
Crenarchaeota.
c.
Euryarchaeota.
d.
Korarchaeota.
e.
Nanoarchaeota.
 

 81. 

Which two groups of archaea should have SSU-rRNA sequences that are most similar to each other?

1. extreme halophiles
2. cyanobacteria
3. methanogens
4. alpha proteobacteria
5. Korarchaeota
a.
1 and 2
b.
1 and 3
c.
2 and 3
d.
2 and 5
e.
3 and 5
 

 82. 

Which group should have had an ancestor whose SSU-rRNA sequences were most similar to those of the common ancestor of all archaea?
a.
Euryarchaeota
b.
Nanoarchaeota
c.
Korarchaeota
d.
Crenarchaeota
e.
Archaeozoa
 

 83. 

What do the archaea used in primary sewage treatment and the archaea that help cattle digest cellulose have in common?
a.
They produce methane as a waste product.
b.
They live only at extremely low pH levels.
c.
They are nitrogen fixers.
d.
They possess both photosystems I and II.
e.
They require extremely high temperatures for reproduction.
 

 84. 

Methane gas emitted by some cattle is produced by gut populations of ____ members of ____.
a.
mutualistic; Euryarchaeota
b.
parasitic; Euryarchaeota
c.
mutualistic; Nanoarchaeota
d.
parasitic; Nanoarchaeota
e.
parasitic; Korarchaeota
 

 85. 

Which prokaryotes should be expected to be most strongly resistant to plasmolysis in hypertonic environments?
a.
extreme halophiles
b.
extreme thermophiles
c.
methanogens
d.
cyanobacteria
e.
nitrogen-fixing bacteria that live in root nodules
 

 86. 

What two features do mycoplasmas and nanoarchaeotes have in common, despite belonging to different domains? They

1. lack peptidoglycan.
2. lack nucleoid regions.
3. have relatively small genomes.
4. lack plasma membranes.
5. are bacteria.
a.
1 and 2
b.
1 and 3
c.
2 and 3
d.
2 and 4
e.
3 and 5
 

 87. 

What is the primary ecological role of prokaryotes?
a.
parasitizing eukaryotes, thus causing diseases
b.
breaking down organic matter
c.
metabolizing materials in extreme environments
d.
adding methane to the atmosphere
e.
serving as primary producers in terrestrial environments
 

 88. 

If all the bacteria on Earth suddenly disappeared, which of the following would be the most likely and most direct result?
a.
The number of organisms on Earth would decrease by 10-20%.
b.
Human populations would thrive in the absence of disease.
c.
There would be little change in Earth's ecosystems.
d.
The recycling of nutrients would be greatly reduced, at least initially.
e.
There would be no more pathogens on Earth.
 

 89. 

Which of the following would most likely occur if all prokaryotes were suddenly to perish?
a.
All life would eventually perish due to disease.
b.
Many organisms would perish as nutrient recycling underwent dramatic reduction.
c.
All life would eventually perish because of increased global warming due to the greenhouse effect.
d.
Only the organisms that feed directly on prokaryotes would perish.
e.
Very little change would occur because prokaryotes are not of significant ecological importance.
 

 90. 

In a hypothetical situation, a bacterium lives on the surface of a leaf, where it obtains nutrition from the leaf's nonliving, waxy covering, and where it inhibits the growth of other microbes that damage the plant. If this bacterium gains access to the inside of a leaf, it causes a fatal disease in the plant. Once the plant dies, the bacterium and its offspring decompose the plant. What is the correct sequence of ecological roles played by the bacterium in that situation? Use only those that apply.

1. nutrient recycler
2. mutualist
3. commensal
4. parasite
5. primary producer
a.
1, 3, 4
b.
2, 3, 4
c.
2, 4, 1
d.
1, 2, 5
e.
1, 2, 3
 

 91. 

In a practice known as crop rotation, farmers alternate a crop of legumes (plants whose roots bear nodules containing Rhizobium) with a crop of nonlegumes. What is the benefit of this practice?
a.
Rhizobium fixes nitrogen, and the fixed nitrogen will fertilize the soil.
b.
It prevents the farmer from being exposed to the same crop pathogens year after year.
c.
It keeps the plants from becoming tolerant of the bacteria in a particular variety of soil.
d.
It keeps the plants from becoming pesticide resistant.
e.
It keeps those bacteria that are plant pathogens from becoming pesticide resistant.
 

 92. 

Foods can be preserved in many ways by slowing or preventing bacterial growth. Which of the following methods would not substantially inhibit bacterial growth?
a.
Refrigeration: Slows bacterial metabolism and growth.
b.
Closing previously opened containers: Prevents more bacteria from entering.
c.
Pickling: Creates a pH at which bacterial enzymes cannot function.
d.
Canning in heavy sugar syrup: Creates osmotic conditions that remove water from bacterial cells.
e.
Irradiation: Kills bacteria by mutating their DNA.
 

 93. 

Many physicians administer antibiotics to patients at the first sign of any disease symptoms. Why can this practice cause more problems for these patients, and for others not yet infected?
a.
The antibiotic administered may kill viruses that had been keeping the bacteria in check.
b.
Antibiotics may cause other side effects in patients.
c.
Overuse of antibiotics can select for antibiotic-resistant strains of bacteria.
d.
Particular patients may be allergic to the antibiotic.
e.
Antibiotics may interfere with the ability to identify the bacteria present.
 

 94. 

Broad-spectrum antibiotics inhibit the growth of most intestinal bacteria. Consequently, a hospital patient who is receiving broad-spectrum antibiotics is most likely to become ____, assuming that nothing is done to counter the reduction of intestinal bacteria.
a.
unable to fix carbon dioxide
b.
antibiotic resistant
c.
unable to fix nitrogen
d.
unable to synthesize peptidoglycan
e.
deficient in certain vitamins
 

 95. 

Protists are alike in that all are
a.
multicellular.
b.
photosynthetic.
c.
marine.
d.
nonparasitic.
e.
eukaryotic.
 

 96. 

All of the following groups had taxonomic significance in the past, but only one is now considered to be a diverse clade. Which group is it?
a.
algae
b.
protist
c.
protozoa
d.
monera
e.
euglenozoa
 

 97. 

Which of the following statements concerning living phytoplanktonic organisms are true?

1. They are important members of communities surrounding deep-sea hydrothermal vents.
2. They are important primary producers in most aquatic food webs.
3. They are important in maintaining oxygen in Earth's seas and atmosphere.
4. They are most often found growing in the sediments of seas and oceans.
5. They can be so concentrated that they affect the color of seawater.
a.
1 and 4
b.
1, 2, and 4
c.
2, 3, and 4
d.
2, 3, and 5
e.
3, 4, and 5
 

 98. 

Biologists have discovered the kingdom Protista to be paraphyletic. Which of the following statements is true, and consistent with this conclusion?
a.
Various combinations of prokaryotic ancestors gave rise to different lineages of protists.
b.
Animals, plants, and fungi arose from different protistan ancestors.
c.
Multicellularity has evolved only once among the protists.
d.
Chloroplasts among various protists are similar to those found in prokaryotes.
e.
The protists arose from a common ancestor that was a parabasalid.
 

 99. 

The strongest evidence for the endosymbiotic origin of eukaryotic organelles is the similarity between extant prokaryotes and which of the following?
a.
nuclei and chloroplasts
b.
mitochondria and chloroplasts
c.
cilia and mitochondria
d.
mitochondria and nuclei
e.
mitochondria and cilia
 

 100. 

According to the endosymbiotic theory of the origin of eukaryotic cells, how did mitochondria originate?
a.
from infoldings of the plasma membrane, coupled with mutations of genes for oxygen-using metabolism
b.
from engulfed, originally free-living prokaryotes
c.
by tertiary endosymbiosis
d.
from the nuclear envelope folding outward and forming mitochondrial membranes
e.
when a protoeukaryote engaged in a symbiotic relationship with a protobiont
 

 101. 

Which of the following statements is consistent with the hypothesis that certain eukaryotic organelles originated as prokaryotic endosymbionts? Such organelles
a.
are roughly the same size as bacteria.
b.
can be cultured on agar since they make all their own proteins.
c.
contain circular DNA molecules.
d.
have ribosomes that are similar to those of bacteria.
e.
A, C, and D
 

 102. 

Which process allows nucleomorphs to be first reduced, and then lost altogether, without the loss of any genetic information from the host cell that ultimately surrounds the nucleomorph?
a.
conjugation
b.
horizontal gene transfer
c.
binary fission
d.
phagocytosis
e.
meiosis
 

 103. 

The chloroplasts of modern plants are thought to have been derived according to which sequence?
a.
cyanobacteria green algae green plants
b.
cyanobacteria green algae fungi green plants
c.
red algae brown algae green algae green plants
d.
red algae cyanobacteria green plants
e.
cyanobacteria red algae green algae green plants
 

 104. 

The evolution of eukaryotes from prokaryotes probably
a.
occurred many times.
b.
involved endosymbiosis on multiple occasions.
c.
allowed for the formation of both complexity and multicellularity.
d.
B and C only
e.
A, B, and C
 

 105. 

The goal in classifying organisms should be to create categories that reflect the evolutionary histories of organisms. What system would be best to use?
a.
a three-kingdom classification system
b.
a five-kingdom classification system
c.
an eight-kingdom classification system
d.
a system that uses as many kingdoms as necessary to be accurate
e.
a system that returns to that used by Linnaeus
 

 106. 

A mixotroph loses its plastids yet continues to survive. Which of the following most likely accounts for its continued survival?
a.
It relies on photosystems that float freely in its cytosol.
b.
It must have gained extra mitochondria when it lost its plastids.
c.
It engulfs organic material by phagocytosis.
d.
It has an endospore.
e.
It is protected by a siliceous case.
 
 
For the following questions, refer to the figure below, which represents a hypothetical eukaryotic cell that is the result of serial endosymbioses involving its mitochondria, one of which is pictured. Labeled arrows (A-E) indicate various membranes in this cell. Responses may be used once, more than once, or not at all.

nar006-1.jpg

 

 107. 

This membrane is homologous to the plasma membrane of the ancestral, gram-negative, aerobically respiring bacterium.
a.
A
b.
B
c.
C
d.
D
e.
E
 

 108. 

This membrane is homologous to an ancestral host plasma membrane and was derived from the primary (first) endosymbiotic event.
a.
A
b.
B
c.
C
d.
D
e.
E
 

 109. 

Which one of the mitochondrial membranes should bear the strongest similarity to the outer membrane of the cell wall of the ancestral, gram-negative, aerobically respiring bacterium?
a.
A
b.
B
c.
C
d.
D
e.
E
 

 110. 

A biologist discovers a new unicellullar organism that possesses more than two flagella and two small, but equal-sized, nuclei. The organism has reduced mitochondria and no chloroplasts. How would you classify this organism?
a.
apicomplexan
b.
diplomonad
c.
ciliate
d.
prokaryote
e.
Chlamydomonas
 

 111. 

Assuming that all of the flagella found among the various types of protists require the same amount of ATP per unit time to operate, and assuming that all of an individual protist's flagella are in use simultaneously, then which of these protists should use the greatest amount of ATP per unit time to move about?
a.
Chlamydomonas
b.
dinoflagellates
c.
euglenids
d.
diplomonads
e.
golden algae
 

 112. 

Which of the following groups does not include many planktonic species?
a.
kinetoplastids.
b.
golden algae.
c.
diatoms.
d.
dinoflagellates.
e.
radiolarians.
 

 113. 

Organisms classified as Euglenozoa have previously been classified as protozoans, protista, plants, and animals. Why the confusion?
a.
Like protozoans, they are unicellular.
b.
Like animals, many are heterotrophic.
c.
Like plants, many are photosynthetic.
d.
A and B only
e.
A, B, and C
 

 114. 

Which two genera have members that can evade the human immune system by frequently changing their surface proteins?

1. Plasmodium
2. Trichomonas
3. Paramecium
4. Trypanosoma
5. Entamoeba
a.
1 and 2
b.
1 and 4
c.
2 and 3
d.
2 and 4
e.
4 and 5
 

 115. 

Which of the following marine organisms produce potent neurotoxins that cause extensive fish kills, contaminate shellfish, and create severe respiratory irritation to humans along the shore?
a.
red algae
b.
dinoflagellates
c.
diplomonads
d.
euglenids
e.
golden algae
 

 116. 

Which structure(s) consist(s), at least in part, of DNA?
a.
Trypanosoma kinetoplast
b.
diplomonad mitochondrion
c.
chlorarachniophytes nucleomorph
d.
A and C only
e.
A, B, and C
 

 117. 

Which of the following statements about dinoflagellates is false?
a.
They possess two flagella.
b.
Some cause red tides.
c.
their walls are composed of cellulose plates.
d.
Many types contain chlorophyll.
e.
Their fossil remains form limestone deposits.
 

 118. 

Which group(s) within the Alveolata include(s) members that are important in ocean food webs, cause(s) red tides that kill many fish, and may even be carnivorous?
a.
ciliates
b.
apicomplexans
c.
dinoflagellates
d.
A and B only
e.
A, B, and C
 

 119. 

Which of the following correctly pairs a protist with one of its characteristics?
a.
kinetoplastids;-slender pseudopodia
b.
plasmodial slime molds-flagellated stages
c.
apicomplexans-parasitic
d.
gymnamoebas-calcium carbonate shell
e.
foraminiferans-abundant in soils
 

 120. 

Which of the following statements concerning protists is false?
a.
All protists are eukaryotic organisms; many are unicellular or colonial.
b.
The organism that causes malaria is transmitted to humans by the bite of the tsetse fly.
c.
All apicomplexans are parasitic.
d.
Cellular slime molds have an amoeboid stage that may be followed by a stage during which spores are produced.
e.
The euglenozoans that are functionally mixotrophic contain chloroplasts.
 

 121. 

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 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?
a.
foraminiferans
b.
radiolarians
c.
ciliates
d.
kinetoplastids
e.
slime molds
 

 122. 

Which of the following is not characteristic of ciliates?
a.
They use cilia as locomotory or feeding structures.
b.
They are relatively complex cells.
c.
They can exchange genetic material with other ciliates by the process of mitosis.
d.
Most live as solitary cells in fresh water.
e.
They have two or more nuclei.
 

 123. 

If one speculates that it requires ten times as many ATP molecules to power a typical flagellum as to power a typical cilium for a given unit of time, and if one assumes that locomotion is the largest energy drain for protists, then which protist should have the largest number of ATP synthases per cell?
a.
Euglena
b.
Chlamydomonas
c.
Giardia
d.
Plasmodium
e.
Paramecium
 

 124. 

Which statement regarding resistance is false?
a.
Many of the oomycetes that cause late potato blight have become resistant to pesticides.
b.
Many of the mosquitoes that transmit malaria to humans have become resistant to pesticides.
c.
Many of the malarial parasites have become resistant to antimalarial drugs.
d.
Many humans have become resistant to antimalarial drugs.
e.
Trichomonas vaginalis is resistant to the normal acidity of the human vagina.
 

 125. 

Why is the filamentous morphology of the water molds considered a case of convergent evolution with the hyphae of fungi?
a.
Fungi are closely related to the water molds.
b.
Body shape reflects ancestor-descendant relationships among organisms.
c.
Filamentous shape is an adaptation for a nutritional mode as a decomposer.
d.
Hyphae and filaments are necessary for locomotion in both groups.
e.
Filamentous body shape is evolutionarily primitive for all eukaryotes.
 

 126. 

The Irish potato famine was caused by an organism that belongs to which group?
a.
bacterium
b.
stramenopile
c.
foraminiferan
d.
apicomplexan
e.
virus
 

 127. 

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

 128. 

Which of the following is correctly described as a primary producer?
a.
oomycete
b.
kinetoplastid
c.
apicomplexan
d.
diatom
e.
radiolarian
 

 129. 

A certain unicellular eukaryote has a siliceous (glasslike) shell and autotrophic nutrition. To which group does it belong?
a.
dinoflagellate
b.
diatom
c.
gymnamoeba
d.
foraminiferan
e.
slime mold
 

 130. 

Diatoms are members of the phytoplankton. Diatoms lack any organelles that might have the "9+2 pattern." They obtain their nutrition from functional chloroplasts, and each diatom is encased within two porous, glasslike valves. Which question would be most important for one interested in the day-to-day survival of individual diatoms?
a.
How does carbon dioxide get into these protists?
b.
How do diatoms move across the surfaces of bodies of water?
c.
How do diatoms keep from sinking into poorly lit waters?
d.
How do diatoms avoid being crushed by the action of waves?
e.
How do diatom sperm cells locate diatom egg cells?
 

 131. 

The largest seaweeds belong to which group?
a.
cyanobacteria
b.
red algae
c.
green algae
d.
brown algae
e.
golden algae
 

 132. 

The following are all characteristic of the water molds (Oomycota) except
a.
the presence of filamentous feeding structures.
b.
flagellated zoospores.
c.
a nutritional mode that can result in the decomposition of dead organic matter.
d.
a similarity to fungi that is the result of evolutionary convergence.
e.
a feeding plasmodium.
 

 133. 

Theoretically, which two of the following present the richest potential sources of silica?

1. marine sediments consisting of foram tests
2. diatomaceous earth
3. marine sediments consisting of radiolarian tests
4. marine sediments consisting of dinoflagellate plates
a.
1 and 2
b.
1 and 4
c.
2 and 3
d.
2 and 4
e.
3 and 4
 

 134. 

Which two heterotrophic organisms most commonly derive nutrition from endosymbiotic relationships with photosynthetic protists?

1. ciliates
2. slime molds
3. parabasalids
4. reef-building coral animals
5. foraminiferans
a.
1 and 2
b.
2 and 3
c.
2 and 4
d.
3 and 4
e.
4 and 5
 

 135. 

A snail-like, coiled, porous shell of calcium carbonate is characteristic of which group?
a.
diatoms
b.
foraminiferans
c.
radiolarians
d.
gymnamoebas
e.
ciliates
 

 136. 

What provides the best rationale for not classifying the slime molds as fungi? Their
a.
SSU-rRNA sequences.
b.
nutritional modes.
c.
choice of habitats.
d.
physical appearance.
e.
reproductive methods.
 

 137. 

Which dichotomous pair of alternatives is highlighted by the life cycle of the cellular slime molds?
a.
prokaryotic versus eukaryotic
b.
plant versus animal
c.
unicellular versus multicellular
d.
diploid versus haploid
e.
autotroph versus heterotroph
 

 138. 

Members of the green algae often differ from members of the plant kingdom in that some green algae
a.
are heterotrophs.
b.
are unicellular.
c.
have chlorophyll a.
d.
store carbohydrates as starch.
e.
have cell walls containing cellulose.
 

 139. 

Which taxonomic group containing eukaryotic organisms is thought to be directly ancestral to the plant kingdom?
a.
golden algae
b.
radiolarians
c.
foraminiferans
d.
apicomplexans
e.
green algae
 

 140. 

Which of the following are actual mutualistic partnerships that involve a protist and a host organism?
a.
green alga : fungal partner of lichen
b.
dinoflagellate : reef-building coral animal
c.
Trichomonas : human
d.
alga : certain foraminiferans
e.
A, B, and D
 
 
Choose the organism from the list below that best fits each of the following descriptions.

A. euglenozoans
B. Chlamydomonas
C. dinoflagellates
D. stramenopiles
E. diplomonads
 

 141. 

possess more than two identical, functional flagella
a.
A
b.
B
c.
C
d.
D
e.
E
 

 142. 

have one flagellum oriented at 90 degrees to the second flagellum
a.
A
b.
B
c.
C
d.
D
e.
E
 

 143. 

have one hairy and one smooth flagellum
a.
A
b.
B
c.
C
d.
D
e.
E
 

 144. 

have two identical, functional flagella, roughly parallel to each other and emerging from about the same site
a.
A
b.
B
c.
C
d.
D
e.
E
 
 
Choose the nutritional mode that is primarily employed by each of the protists listed below.

A. autotrophic
B. mixotrophic
C. heterotrophic (by absorption)
D. heterotrophic (by ingestion)
 

 145. 

diatoms
a.
A
b.
B
c.
C
d.
D
e.
E
 

 146. 

phagocytic euglenids that possess functional chloroplasts
a.
A
b.
B
c.
C
d.
D
e.
E
 
 
You are given five test tubes, each containing an unknown protist, and your task is to read the description below and match these five protists to the correct test tube.

A. Paramecium
B. Navicula (diatom)
C. Pfiesteria (dinoflagellate)
D. Entamoeba
E. Plasmodium


In test tube 1, you observe an organism feeding. Your sketch of the organism looks very similar to the figure below. When light, especially red and blue light, is shone on the tubes, oxygen bubbles accumulate on the inside of test tubes 2 and 3. Chemical analysis of test tube 3 indicates the presence of substantial amounts of silica. Chemical analysis of test tube 2 indicates the presence of a chemical that is toxic to fish and humans. Microscopic analysis of organisms in tubes 2, 4, and 5 reveals the presence of permanent, membrane-bounded sacs just under the plasma membrane. Microscopic analysis of organisms in tube 4 reveals the presence of an apicoplast in each. Microscopic analysis of the contents in tube 5 reveals the presence of one large nucleus and several small nuclei in each organism.

nar009-1.jpg

 

 147. 

Test tube 2 contains
a.
A
b.
B
c.
C
d.
D
e.
E
 

 148. 

Test tube 4 contains
a.
A
b.
B
c.
C
d.
D
e.
E
 

 149. 

Test tube 5 contains
a.
A
b.
B
c.
C
d.
D
e.
E
 

 150. 

Test tube 1 contains
a.
A
b.
B
c.
C
d.
D
e.
E
 

 151. 

Which of the following do all fungi have in common?
a.
meiosis in basidia
b.
coenocytic hyphae
c.
sexual life cycle
d.
absorption of nutrients
e.
symbioses with algae
 

 152. 

The hydrolytic digestion of which of the following should produce the monomer, an aminated molecule of -glucose?
a.
insect exoskeleton
b.
plant cell walls
c.
fungal cell walls
d.
A and C only
e.
A, B and C
 

 153. 

When a mycelium infiltrates an unexploited source of dead organic matter, what are most likely to appear within the food source soon thereafter?
a.
haustoria
b.
soredia
c.
exoenzymes
d.
increased oxygen levels
e.
larger bacterial populations
 

 154. 

Which of the following is not a characteristic of hyphate fungi (fungi featuring hyphae)?
a.
They acquire their nutrients by absorption.
b.
Their body plan is a netlike mass of filaments called a mycelium.
c.
Their cell walls consist mainly of cellulose microfibrils.
d.
They may be saprobes, parasites, or mutualistic symbionts.
e.
The nuclei of the mycelia are typically haploid.
 

 155. 

The functional significance of porous septa in certain fungal hyphae is most similar to that represented by the ____ of certain animal cells, and by the ____ of certain plant cells.
a.
desmosomes; tonoplasts
b.
gap junctions; plasmodesmata
c.
tight junctions; plastids
d.
centrioles; plastids
e.
flagella; central vacuoles
 

 156. 

What is the primary role of a mushroom's underground mycelium?
a.
absorbing nutrients
b.
anchoring
c.
sexual reproduction
d.
asexual reproduction
e.
protection
 

 157. 

What do fungi and arthropods have in common?
a.
Both groups are commonly coenocytic.
b.
The haploid state is dominant in both groups.
c.
Both groups are predominantly saprobic in nutrition.
d.
The protective coats of both groups are made of chitin.
e.
Both groups have cell walls.
 

 158. 

In septate fungi, what structures allow cytoplasmic streaming to distribute needed nutrients, synthesized compounds, and organelles throughout the hyphae?
a.
chitinous layers in cell walls
b.
pores in septal walls
c.
complex microtubular cytoskeletons
d.
two nuclei
e.
tight junctions that form in septal walls between cells
 

 159. 

What best accounts for the extremely fast growth of a fungal mycelium?
a.
a rapid distribution of synthesized proteins by cytoplasmic streaming
b.
their lack of motility that requires rapid spread of hyphae
c.
a long tubular body shape
d.
the readily available nutrients from their predatory mode of nutrition
e.
a dikaryotic condition that supplies greater amounts of proteins and nutrients
 

 160. 

Both fungus-farming ants and their fungi can synthesize the same structural polysaccharide from the -glucose molecules that are derived from the digestion of plant leaves. What is the synthesized polysaccharide?
a.
amylopectin
b.
chitin
c.
cellulose
d.
lignin
e.
glycogen
 

 161. 

Which of the following cannot be assigned to any one kind of morphology (that is, unicellular or hyphate) or to any one fungal taxon?
a.
yeasts
b.
ascomycetes
c.
club fungi
d.
bread molds
e.
ergot fungi
 

 162. 

If all of their nuclei are equally active transcriptionally, then the cells of both dikaryotic and heterokaryotic fungi are essentially like ____ cells in terms of the gene products they can make.
a.
haploid
b.
diploid
c.
alloploid
d.
completely homozygous
e.
completely hemizygous
 

 163. 

What is a fungal process that has the opposite effect on chromosome number than the effect of meiosis?
a.
mitosis
b.
plasmogamy
c.
crossing over
d.
binary fission
e.
karyogamy
 

 164. 

If a single, diploid G2 nucleus in an ascus contains 400 nanograms (ng) of DNA, then a single mature ascospore of this species should contain ____ ng of DNA, carried on a total of ____ chromosomes.
a.
100; 7
b.
100; 14
c.
200; 7
d.
200; 14
e.
400; 14
 

 165. 

What is the ploidy of a single mature Neurospora ascospore?
a.
haploid
b.
diploid
c.
triploid
d.
tetraploid
e.
polyploid
 

 166. 

Each of the eight ascospores present at the end of mitosis has the same chromosome number and DNA content (ng) as each of the four cells at the end of meiosis. What must have occurred between the round of meiosis and the round of mitosis?
a.
double fertilization
b.
crossing over
c.
nondisjunction
d.
autopolyploidy
e.
S phase
 

 167. 

Cytokinesis is to nuclear division as ____ is to karyogamy.
a.
syngamy
b.
plasmogamy
c.
gametogenesis
d.
endosymbiosis
e.
parasitism
 

 168. 

A chemical secreted by female Bombyx moths helps the male of the species locate her, at which time sexual reproduction may occur. This chemical is most similar in function to which chemicals used by certain fungi?
a.
chitin
b.
exoenzymes
c.
lysergic acids
d.
aflatoxins
e.
pheromones
 

 169. 

Which of the following is characterized by the lack of an observed sexual phase in its members' life cycle?
a.
Ascomycota
b.
Basidiomycota
c.
Chytridiomycota
d.
Deuteromycota
e.
Zygomycota
 

 170. 

A biologist is trying to classify a new organism on the basis of the following characteristics: fungus-like in appearance, reproduces by conidia, has no apparent sexual phase, and parasitizes woody plants. If asked for advice, to which group would you assign this new species?
a.
Deuteromycota
b.
Zygomycota
c.
Ascomycota
d.
Basidiomycota
e.
Glomeromycota
 

 171. 

Which of these structures are most likely to be a component of both chytrid zoospores and motile animal cells?
a.
chloroplasts
b.
9 + 2 pattern of microtubules in flagella
c.
cell walls composed of chitin
d.
heterokaryons
e.
haustoria
 

 172. 

If the choanoflagellate protist from which animals are thought to have evolved were classified as an opisthokont, then what should be true of these choanoflagellates?
a.
They should also have given rise to the chytrids.
b.
They should be the common ancestor of the chytrids and the zygomycetes.
c.
The end of the cell from which the flagellum emerges should be homologous to the posterior ends of animal sperm cells and chytrid zoospores.
d.
They should perform heterotrophy by secretion of exoenzymes.
e.
Like diplomonads and parabasalids, they should bear multiple flagella.
 

 173. 

Considered at the taxonomic level of the kingdom, which of the following constitute a monophyletic clade?
a.
mosses and zygomycetes
b.
chytrids and fungi
c.
algae and ascomycetes
d.
chytrids and slime molds
e.
mosses and fungi
 

 174. 

If the multicellular condition is an adaptation, rather than an accident, then the multicellular condition of animals and fungi seems to have arisen
a.
due to common ancestry.
b.
by convergent evolution.
c.
by inheritance of acquired traits.
d.
by natural means, and is a homology.
e.
More than one of these is correct.
 

 175. 

Asexual reproduction in yeasts occurs by budding. Due to unequal cytokinesis, the "bud" cell receives less cytoplasm than the parent cell. Which of the following should be true of the smaller cell until it reaches the size of the larger cell?
a.
It should produce fewer fermentation products per unit time.
b.
It should produce ribosomal RNA at a slower rate.
c.
It should be transcriptionally less active.
d.
It should have reduced motility.
e.
It should have a smaller nucleus.
 
 
Match the phyla below with the descriptions that follow. Each term may be used once, more than once, or not at all.

A. Zygomycota
B. Ascomycota
C. Basidiomycota
D. Glomeromycota
E. Chytridiomycota
 

 176. 

This phylum contains organisms that most closely resemble the common ancestor of fungi and animals.
a.
A
b.
B
c.
C
d.
D
e.
E
 

 177. 

This phylum formerly included the members of the new phylum Glomeromycota, and may also contain the Microsporidia.
a.
A
b.
B
c.
C
d.
D
e.
E
 

 178. 

This phylum contains the mushrooms, shelf fungi, and puffballs.
a.
A
b.
B
c.
C
d.
D
e.
E
 

 179. 

Members of this phylum form arbuscular mycorrhizae.
a.
A
b.
B
c.
C
d.
D
e.
E
 

 180. 

You have been given the assignment of locating living members of the phylum Glomeromycota. Where is the best place to look for these fungi?
a.
between the toes of a person with "athlete's foot"
b.
in stagnant freshwater ponds
c.
the roots of vascular plants
d.
growing on rocks and tree bark
e.
the kidneys of cattle
 

 181. 

What are the sporangia of bread molds?
a.
asexual structures that produce haploid spores
b.
asexual structures that produce diploid spores
c.
sexual structures that produce haploid spores
d.
sexual structures that produce diploid spores
e.
vegetative structures with no role in reproduction
 

 182. 

The ascomycetes get their name from which aspect of their life cycle?
a.
vegetative growth form
b.
asexual spore production
c.
sexual structures
d.
shape of the spore
e.
type of vegetative mycelium
 

 183. 

Which of these fungal structures are structurally and functionally most alike?
a.
conidia and basidiocarps
b.
sporangia and hyphae
c.
soredia and gills
d.
haustoria and arbuscles
e.
zoospores and mycelia
 

 184. 

You are given an organism to identify. It has a fruiting body that contains many structures with eight haploid spores lined up in a row. What kind of a fungus is this?
a.
zygomycete
b.
ascomycete
c.
deuteromycete
d.
chytrid
e.
basidiomycete
 

 185. 

Which has the least affiliation with all of the others?
a.
Glomeromycota
b.
endomycorrhizae
c.
lichens
d.
arbuscular mycorrhizae
e.
symbiotic fungi
 

 186. 

Mushrooms with gills, typically available in supermarkets, have meiotically produced spores located in or on ____ and belong to the phylum ____.
a.
asci; Basidiomycota
b.
hyphae; Zygomycota
c.
basidia; Basidiomycota
d.
asci; Ascomycota
e.
hyphae; Ascomycota
 

 187. 

A fungal spore germinates, giving rise to a mycelium that grows outward into the soil surrounding the site where the spore originally landed. What process best accounts for the observation that, upon reaching sexual maturity, this fungus produces a nearly circular fairy ring despite the fact that organic nutrients are not evenly distributed in the soil?
a.
karyogamy
b.
plasmogamy
c.
alternation of generations
d.
fermentation
e.
cytoplasmic streaming
 

 188. 

The nonpathogenic fungus that produces a fairy ring grows outward in concentric rings over the course of years. As a result, what should be less abundant in the soil within the ring soon after the fungal hyphae colonize it?
a.
antibiotic molecules
b.
living organic matter
c.
living plant roots
d.
dead organic matter
e.
fungal exoenzymes
 

 189. 

Lichens are symbiotic associations of fungi and
a.
mosses.
b.
cyanobacteria.
c.
green algae.
d.
either A or B
e.
either B or C
 

 190. 

The symbiotic associations involving roots and soil fungi are considered
a.
parasitic.
b.
mutualistic.
c.
commensal.
d.
harmful to the plant partner.
e.
the beginning stages of the formation of lichens.
 

 191. 

Which of the following best describes the physical relationship of the partners involved in lichens?
a.
Fungal cells are enclosed within algal cells.
b.
Lichen cells are enclosed within fungal cells.
c.
Photosynthetic cells are surrounded by fungal hyphae.
d.
The fungi grow on rocks and trees and are covered by algae.
e.
Algal cells and fungal cells mix together without any apparent structure.
 

 192. 

If haustoria were to appear within the photosynthetic partner of a lichen, and if the growth rate of the photosynthetic partner consequently slowed substantially, then this would support the claim that
a.
algae and cyanobacteria are autotrophic.
b.
lichens are not purely mutualistic relationships.
c.
algae require maximal contact with the fungal partner in order to grow at optimal rates.
d.
fungi get all of the nutrition they need via the "leakiness" of photosynthetic partners.
e.
soredia are asexual reproductive structures combining both the fungal and photosynthetic partners.
 

 193. 

How are the vascular plants that are involved in mycorrhizae and the photosynthetic cells that are involved in lichens alike?
a.
They provide organic nutrients to fungal partners.
b.
They secrete acids that keep the fungal partner from growing too quickly.
c.
They are in intimate associations with chytrids.
d.
They are digested by fungal exoenzymes while still alive.
e.
They contain endosymbiotic fungi.
 

 194. 

When pathogenic fungi are found growing on the roots of grape vines, grape farmers sometimes respond by covering the ground around their vines with plastic sheeting and pumping a gaseous fungicide into the soil. The most important concern of viticulturists who engage in this practice should be that the
a.
fungicide might also kill the native yeasts residing on the surfaces of the grapes.
b.
fungicide isn't also harmful to insect pests.
c.
lichens growing on the vines' branches are not harmed.
d.
fungicide might also kill mycorrhizae.
e.
sheeting is transparent so that photosynthesis can continue.
 

 195. 

The terms below all refer to symbiotic relationships that involve fungi except
a.
pathogens.
b.
mycoses.
c.
spore production.
d.
lichens.
e.
mycorrhizae.
 

 196. 

If Penicillium secreted penicillin while involved in a lichen relationship, what must have been true about its partner?
a.
It should have lacked peptidoglycan in its cell wall.
b.
It was probably a green alga.
c.
It was probably not a member of the domain Bacteria.
d.
It was probably not a heterotrophic prokaryote.
e.
All of these are true.
 

 197. 

Both fungus-derived antibiotics and hallucinogens used by humans probably evolved in fungi as a means to
a.
reduce competition for nutrients.
b.
help humanity survive.
c.
promote their ingestion of foodstuffs.
d.
eliminate other fungi.
e.
discourage animal predators.
 

 198. 

A billionaire buys a sterile volcanic island that recently emerged from the sea. To speed the arrival of conditions necessary for plant growth, the billionaire might be advised to aerially sow ____ over the island.
a.
basiodiospores
b.
spores of ectomycorrhizae
c.
soredia
d.
yeasts
e.
leaves (as food for fungus-farming ants)
 

 199. 

The following conditions are all caused by a fungus except
a.
AIDS.
b.
athlete's foot.
c.
ringworm.
d.
candidiasis (Candida yeast infection).
e.
coccidioidomycosis.
 

 200. 

Fungi are beneficial to agriculture in all of the following ways except in that they
a.
recycle nutrients that are tied up in dead organic matter.
b.
increase the ability of most vascular plants to absorb minerals from the soil.
c.
contribute to the initial stages of soil formation from rock.
d.
form mycoses on leaves and stems.
e.
may harbor photosynthetic partners that add nitrogenous compounds to the soil.
 


 
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