1) All protists are
A) unicellular.
B) eukaryotic.
C) symbionts.
D) monophyletic.
E) mixotrophic.
Answer: B
2) Biologists have long been aware that the defunct kingdom Protista
is polyphyletic. Which of these statements is most consistent with
this conclusion?
A) Many species within this kingdom were once
classified as monerans.
B) Animals, plants, and fungi arose from
different protist ancestors.
C) The eukaryotic condition has
evolved more than once among the protists.
D) Chloroplasts among
various protists are similar to those found in prokaryotes.
E)
Some protists, all animals, and all fungi share a protist common
ancestor, but these protists, animals, and fungi are currently
assigned to three different kingdoms.
Answer: C
3) 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 proteins in
energy-transfer reactions
B) from engulfed, originally
free-living proteobacteria
C) by secondary endosymbiosis
D) from the nuclear envelope folding outward and forming
mitochondrial membranes
E) when a protoeukaryote engaged in a
symbiotic relationship with a protocell
Answer: B
4) Which process could have allowed the nucleomorphs of
chlorarachniophytes to be reduced, without the net loss of any genetic
information?
A) conjugation
B) horizontal gene transfer
C) binary fission
D) phagocytosis
E) meiosis
Answer: B
5) An individual 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 or
by absorption.
D) It has an endospore.
E) It is protected
by a case made of silica.
Answer: C
6) Which of the following was derived from an ancestral
cyanobacterium?
A) chloroplast
B) mitochondrion
C)
hydrogenosome
D) mitosome
E) Two of the responses above
are correct.
Answer: A
7) 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
Answer: B
8) Which of the following pairs of protists and their characteristics
is mismatched?
A) apicomplexans–internal parasites
B)
golden algae–planktonic producers
C) euglenozoans–unicellular
flagellates
D) ciliates–red tide organisms
E)
entamoebas–ingestive heterotrophs
Answer: D
9) Which of the following statements about dinoflagellates is true?
A) They possess two flagella.
B) All known varieties are
autotrophic.
C) Their walls are usually composed of silica
plates.
D) Many types lack mitochondria.
E) Their dead
cells accumulate on the seafloor, and are mined to serve as a
filtering material.
Answer: A
10) 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?
A)
foraminiferans
B) radiolarians
C) ciliates
D)
kinetoplastids
E) slime molds
Answer: C
11) Which of the following is characteristic of ciliates?
A)
They use pseudopods as locomotory structures or as feeding structures.
B) They are relatively specialized cells.
C) They can
exchange genetic material with other ciliates by the process of
mitosis.
D) Most live as solitary autotrophs in fresh water.
E) They are often multinucleate.
Answer: E
12) Which process results in genetic recombination, but is separate
from the process by which the population size of Paramecium increases?
A) budding
B) meiotic division
C) mitotic division
D) conjugation
E) binary fission
Answer: D
13) Why is the filamentous morphology of the water molds considered a
case of convergent evolution?
A) Water molds evolved from
filamentous fungi.
B) Body shape reflects ancestor-descendant
relationships among organisms.
C) In both cases, filamentous
shape is an adaptation for the absorptive nutritional mode of a
decomposer.
D) Filamentous body shape is evolutionarily
ancestral for all eukaryotes.
E) Both the first and second
responses above are correct.
Answer: C
14) 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
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.
Answer: E
15) Diatoms are mostly asexual 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 with their glasslike valves?
B) How do diatoms get
transported from one location on the water's surface layers to another
location on the surface?
C) How do diatoms with their glasslike
valves keep from sinking into poorly lit waters?
D) How do
diatoms with their glasslike valves avoid being shattered by the
action of waves?
E) How do diatom sperm cells locate diatom egg cells?
Answer: C
16) A large seaweed that floats freely on the surface of deep bodies
of water would be expected to lack which of the following?
A)
thalli
B) bladders
C) holdfasts
D) gel-forming polysaccharides
Answer: C
17) Which of the following is a characteristic of the water molds
(oomycetes)?
A) the presence of filamentous feeding structures
B) zoospores that are spread by breezes
C) the same
nutritional mode as possessed by cyanobacteria
D) a
morphological similarity to fungi that is the result of common
ancestry
E) a feeding Plasmodium
Answer: A
18) Reinforced, threadlike pseudopods that can perform phagocytosis
are generally characteristic of which group?
A) radiolarians and
forams
B) gymnamoebas
C) entamoebas
D) amoeboid
stage of cellular slime molds
E) oomycetes
Answer: A
19) A snail-like, coiled, porous test (shell) of calcium carbonate is
characteristic of which group?
A) diatoms
B)
foraminiferans
C) radiolarians
D) gymnamoebas
Answer: B
20) The chloroplasts of land plants are thought to have been derived
according to which evolutionary sequence?
A) cyanobacteria →
green algae → land plants
B) cyanobacteria → green algae → fungi
→ land plants
C) red algae → brown algae → green algae → land
plants
D) cyanobacteria → red algae → green algae → land plants
Answer: A
21) The chloroplasts of all of the following are thought to be
derived from ancestral red algae, except those of
A) golden
algae.
B) diatoms.
C) dinoflagellates.
D) green
algae.
E) brown algae.
Answer: D
22) A biologist discovers an alga that is marine, multicellular, and
lives at a depth reached only by blue light. This alga probably
belongs to which group?
A) red algae
B) brown algae
C) green algae
D) dinoflagellates
E) golden algae
Answer: A
23) Green algae differ from land plants in that many green algae
A) are heterotrophs.
B) are unicellular.
C) have
plastids.
D) have alternation of generations.
E) have cell
walls containing cellulose.
Answer: B
24) 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?
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.
Answer: C
25) The best evidence for not classifying the slime molds as fungi
comes from slime molds'
A) DNA sequences.
B) nutritional
modes.
C) choice of habitats.
D) physical appearance.
E) reproductive methods.
Answer: A
26) Which pair of alternatives is highlighted by the life cycle of
the cellular slime molds, such as Dictyostelium?
A) prokaryotic
or eukaryotic
B) unicellular or multicellular
C) diploid
or haploid
D) autotroph or heterotroph
Answer: B
27) Which of the following statements concerning protists is true?
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.
Answer: A
28) Which of the following is correctly described as a primary
producer?
A) oomycete
B) kinetoplastid
C)
apicomplexan
D) diatom
E) radiolarian
Answer: D
29) You are given the task of designing an aerobic, mixotrophic
protist that can perform photosynthesis in fairly deep water (for
example, 250 m deep), and can also crawl about and engulf small
particles. With which two of the following structures would you
provide your protist?
1. hydrogenosome
2. apicoplast
3. pseudopods
4. chloroplast from red alga
5. chloroplast from green
alga
A) 1 and 2
B) 2 and 3
C) 2 and 4
D) 3 and 4
E) 4 and 5
Answer: D
30) You are given the task of designing an aquatic protist that is a
primary producer. It cannot swim on its own, yet must stay in well-lit
surface waters. It must be resistant to physical damage from wave
action. It should be most similar to a(n)
A) diatom.
B)
dinoflagellate.
C) apicomplexan.
D) red alga.
E) radiolarian.
Answer: A
31) Similar to most amoebozoans, the forams and the radiolarians also
have pseudopods, as do some of the white blood cells of animals
(monocytes). If one were to erect a taxon that included all organisms
that have cells with pseudopods, what would be true of such a taxon?
A) It would be polyphyletic.
B) It would be paraphyletic.
C) It would be monophyletic.
D) It would include all eukaryotes.
Answer: A
32) You are designing an artificial drug-delivery "cell"
that can penetrate animal cells. Which of these protist structures
should provide the most likely avenue for research along these lines?
A) pseudopods
B) apical complex
C) excavated feeding
grooves
D) nucleomorphs
E) mitosomes
Answer: B
33) A gelatinous seaweed that grows in shallow, cold water and
undergoes heteromorphic alternation of generations is most probably
what type of alga?
A) red
B) green
C) brown
D) yellow
Answer: C
34) Which of the following are actual mutualistic partnerships that
involve a protist and a host organism?
A) cellulose-digesting
gut protistswood-eating termites
B)
dinoflagellatesreef-building coral animals
C)
Trichomonashumans
D) algaecertain foraminiferans
E) all
except that involving humans
Answer: E
35) 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?
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.
Answer: B
You are given five test tubes, each containing an unknown protist,
and your task is to read the following description and match these
five protists to the correct test tube.
In test tube 1, you observe an organism feeding. Your sketch of
the organism looks very similar to Figure 28.1. 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 test
tubes 2, 4, and 5 reveals the presence of permanent, membrane-bounded
sacs just under the plasma membrane. Microscopic analysis of organisms
in test tube 4 reveals the presence of an apicoplast in each.
Microscopic analysis of the contents in test tube 5 reveals the
presence of one large nucleus and several small nuclei in each
organism.
36) Test tube 2 contains
A) Paramecium.
B) Navicula
(diatom).
C) Pfiesteria (dinoflagellate).
D) Entamoeba.
E) Plasmodium.
Answer: C
You are given five test tubes, each containing an unknown protist,
and your task is to read the following description and match these
five protists to the correct test tube.
In test tube 1, you observe an organism feeding. Your sketch of
the organism looks very similar to Figure 28.1. 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 test
tubes 2, 4, and 5 reveals the presence of permanent, membrane-bounded
sacs just under the plasma membrane. Microscopic analysis of organisms
in test tube 4 reveals the presence of an apicoplast in each.
Microscopic analysis of the contents in test tube 5 reveals the
presence of one large nucleus and several small nuclei in each
organism.
37) Test tube 4 contains
A) Paramecium.
B) Navicula
(diatom).
C) Pfiesteria (dinoflagellate).
D) Entamoeba.
E) Plasmodium.
Answer: E
You are given five test tubes, each containing an unknown protist,
and your task is to read the following description and match these
five protists to the correct test tube.
In test tube 1, you observe an organism feeding. Your sketch of
the organism looks very similar to Figure 28.1. 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 test
tubes 2, 4, and 5 reveals the presence of permanent, membrane-bounded
sacs just under the plasma membrane. Microscopic analysis of organisms
in test tube 4 reveals the presence of an apicoplast in each.
Microscopic analysis of the contents in test tube 5 reveals the
presence of one large nucleus and several small nuclei in each
organism.
38) Test tube 5 contains
A) Paramecium.
B) Navicula
(diatom).
C) Pfiesteria (dinoflagellate).
D) Entamoeba.
E) Plasmodium.
Answer: A
You are given five test tubes, each containing an unknown protist,
and your task is to read the following description and match these
five protists to the correct test tube.
In test tube 1, you observe an organism feeding. Your sketch of
the organism looks very similar to Figure 28.1. 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 test
tubes 2, 4, and 5 reveals the presence of permanent, membrane-bounded
sacs just under the plasma membrane. Microscopic analysis of organisms
in test tube 4 reveals the presence of an apicoplast in each.
Microscopic analysis of the contents in test tube 5 reveals the
presence of one large nucleus and several small nuclei in each
organism.
39) Test tube 3 contains
A) Paramecium.
B) Navicula
(diatom).
C) Pfiesteria (dinoflagellate).
D) Entamoeba.
E) Plasmodium.
Answer: B
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
40) Water's density and, consequently, its buoyancy decrease at
warmer temperatures. Based on this consideration and using data from
Table 28.1, at which time of year should one expect diatoms to be
storing excess calories mostly as oil?
A) mid-winter
B)
early spring
C) late summer
D) late fall
Answer: C
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
41) Judging from Table 28.1 and given that water's density and,
consequently, its buoyancy decrease at warmer temperatures, in which
environment should diatoms (and other suspended particles) sink most
slowly?
A) cold fresh water
B) warm fresh water
C)
cold seawater
D) warm seawater
E) warm brackish water
Answer: C
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
42) 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
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.
Answer: A
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.
43) 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
A) Robert Koch.
B) Robert
Hooke.
C) Isaac Newton.
D) van Leeuwenhoek.
E) Louis Pasteur.
Answer: D
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.
44) 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
A) peptidoglycan.
B)
mitochondria or mitosomes.
C) anaerobic metabolic pathways.
D) nuclear envelopes.
E) microtubules.
Answer: C
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.
45) Giardia's mitosome can be said to be "doubly
degenerate," because it is a degenerate form of ________,
an organelle that is itself a degenerate form of ________.
A) nucleus; archaean
B) nucleus; bacterium
C)
mitochondrion; proteobacterium
D) mitochondrion; spirochete
E) chloroplast; cyanobacterium
Answer: C
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.
46) The mitosome of Giardia has no DNA within it. If it did
contain DNA, then what predictions should we be able to make about its
DNA?
1. It is linear.
2. It is circular.
3. It has many
introns.
4. It has few introns.
5. It is not associated
with histone proteins.
6. It is complexed with histone proteins.
A) 1, 3, and 5
B) 1, 4, and 5
C) 2, 3, and 6
D) 2, 4, and 5
E) 2, 4, and 6
Answer: D
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.
47) Given the putative ancestry of Giardia's mitosome, what
should we predict is true of the mitosome?
A) It has electron
transport systems that use oxygen as the final electron acceptor.
B) It has a double membrane.
C) It has thylakoids.
D) It contains microtubules, arranged in the "9 + 2
pattern."
E) It contains 80S (eukaryotic) ribosomes.
Answer: B
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.
48) Given its mode of reproduction and internal structures,
which of the following should be expected to occur in Giardia at some
stage of its life cycle?
1. separation (segregation) of daughter chromosomes
2.
crossing over
3. meiosis
A) 1 only
B) 3 only
C) 1 and 2
D) 1 and 3
E) 2 and 3
Answer: A
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.
49) 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
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.
Answer: E
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.
50) 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?
A) 5; 5
B) 5; 10
C) 10; 10
D) 10;
20
E) 20; 20
Answer: C
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.
51) During passage through the large intestine, a trophozoite
will often secrete a case around itself, forming a cyst. Cysts contain
four haploid nuclei. When cysts "hatch" within a new host,
two trophozoites are released. Thus, which of the following must
happen within the cyst, prior to hatching?
1. meiosis
2. nuclear division
3. S phase
4.
binary fission
A) 1 only
B) 1 and 2
C) 2 and 3
D) 2 and 4
E) 2, 3, and 4
Answer: E
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.
52) The cysts of Giardia are most analogous to the
A)
mitochondria of ancestral diplomonads.
B) nuclei of archaeans.
C) endospores of bacteria.
D) capsids of viruses.
Answer: C
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.
53) 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?
A) plasmids;
conjugation
B) plasmids; transformation
C) nucleus;
horizontal gene transfer
D) nucleus; S phase
Answer: C
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.
54) The primary treatment for giardiasis (infection with
Giardia), as well as for trichomoniasis (infection with Trichomonas
vaginalis) and for amoebic dysentery (infection with Entamoeba
histolytica), is a drug marketed as Flagyl (generic name is
metronidazole). The drug also kills anaerobic gut bacteria.
Consequently, which of these are cues that Flagyl's mode of action has
nothing to do with attacking or disabling the parasites' flagella, as
the drug's name might imply?
1. It would also harm the
flagellated lining of the human intestine.
2. Entamoeba
possesses pseudopods, not flagella, yet it is killed by Flagyl.
3. Prokaryotic flagella and eukaryotic flagella are radically
different from each other and unlikely to be harmed by the same
chemical.
4. Not all anaerobic gut bacteria possess flagella,
yet it kills these bacteria.
A) 1 and 2
B) 1 and 3
C) 2 and 3
D) 1, 2, and
4
E) 2, 3, and 4
Answer: E
Paulinella chromatophora is one of the few cercozoans that is
autotrophic, carrying out aerobic photosynthesis with its two
elongated "cyanelles." The cyanelles are contained within
vesicles of the host cell, and each is derived from a cyanobacterium,
though not the same type of cyanobacterium that gave rise to the
chloroplasts of algae and plants.
55) The closest living relative of P. chromatophora is the
heterotroph, P. ovalis. What type of evidence permits biologists to
make this claim about relatedness?
A) morphological
B)
ecological
C) biochemical
D) genetic
E) fossil
Answer: D
Paulinella chromatophora is one of the few cercozoans that is
autotrophic, carrying out aerobic photosynthesis with its two
elongated "cyanelles." The cyanelles are contained within
vesicles of the host cell, and each is derived from a cyanobacterium,
though not the same type of cyanobacterium that gave rise to the
chloroplasts of algae and plants.
56) The closest living relative of P. chromatophora is the
heterotroph, P. ovalis. P. ovalis uses threadlike pseudopods to
capture its prey, which it digests internally. Which of the following,
if observed, would be the best reason for relabeling P. chromatophora
as a mixotroph?
A) a threadlike pseudopod
B) a pigmented
central vacuole, surrounded by a tonoplast
C) a vacuole with
food inside
D) a secretory vesicle
E) a contractile vacuole
Answer: C
Paulinella chromatophora is one of the few cercozoans that is
autotrophic, carrying out aerobic photosynthesis with its two
elongated "cyanelles." The cyanelles are contained within
vesicles of the host cell, and each is derived from a cyanobacterium,
though not the same type of cyanobacterium that gave rise to the
chloroplasts of algae and plants.
57) P. chromatophora secretes around itself a test, or case, of
plates made of silica. Which of the following is another rhizarian
that would be in competition with P. chromatophora for the silica
needed to make these plates, assuming limited quantities of silica in
the environment?
A) radiolarians
B) foraminiferans
C) all other amoeboid cells
D) all other rhizaria
E) diatoms
Answer: A
Paulinella chromatophora is one of the few cercozoans that is
autotrophic, carrying out aerobic photosynthesis with its two
elongated "cyanelles." The cyanelles are contained within
vesicles of the host cell, and each is derived from a cyanobacterium,
though not the same type of cyanobacterium that gave rise to the
chloroplasts of algae and plants.
58) Which of the following represents the true significance of
the finding that the cyanelles of P. chromatophora stem from a
different type of cyanobacterium than gave rise to chloroplasts?
A) This finding indicates that there is a second evolutionary
lineage of photosynthetic eukaryotes.
B) This finding represents
the first time that primary endosymbiosis has been directly observed.
C) This finding is the strongest evidence yet for the theory of
endosymbiosis.
D) This finding is an example of the phenomenon
known as "serial endosymbiosis."
E) This finding is
the first evidence that eukaryotic cells do not necessarily digest
prokaryotic cells that manage to gain access to their cytoplasm.
Answer: A
Paulinella chromatophora is one of the few cercozoans that is
autotrophic, carrying out aerobic photosynthesis with its two
elongated "cyanelles." The cyanelles are contained within
vesicles of the host cell, and each is derived from a cyanobacterium,
though not the same type of cyanobacterium that gave rise to the
chloroplasts of algae and plants.
59) 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?
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.
Answer: B
Paulinella chromatophora is one of the few cercozoans that is
autotrophic, carrying out aerobic photosynthesis with its two
elongated "cyanelles." The cyanelles are contained within
vesicles of the host cell, and each is derived from a cyanobacterium,
though not the same type of cyanobacterium that gave rise to the
chloroplasts of algae and plants.
60) If true, which of the following would be most important in
determining whether P. chromatophora's cyanelle is still an
endosymbiont, or is an organelle, as the term cyanelle implies?
A) If P. chromatophora is less fit without its cyanelle than
with it.
B) If the cyanelle is less fit without the host
cercozoan than with it.
C) If there is ongoing metabolic
cooperation between the cyanelle and the host cercozoan.
D) If
the magnesium-containing porphyrin ring in the cyanelle's chlorophyll
molecules is built by the cyanelle, whereas the organic portion of the
chlorophyll molecules is built by the host cercozoan.
E) If
there has been movement of genes from the cyanelle genome to the
nuclear genome, such that these genes are no longer present in the
cyanelle genome.
Answer: E
Paulinella chromatophora is one of the few cercozoans that is
autotrophic, carrying out aerobic photosynthesis with its two
elongated "cyanelles." The cyanelles are contained within
vesicles of the host cell, and each is derived from a cyanobacterium,
though not the same type of cyanobacterium that gave rise to the
chloroplasts of algae and plants.
61) If true, which of the following is the best evidence that
the cyanelles are providing nutrition (in other words, calories) to
the surrounding cercozoan?
A) If the cyanelle performs aerobic
photosynthesis.
B) If the vesicle membrane that surrounds each
cyanelle possesses glucose-transport proteins.
C) If the
cyanelle performs aerobic respiration.
D) If radiolabeled 14CO2
enters the cyanelle and if, subsequently, radiolabeled glucose is
present in cercozoan cytosol.
E) If radiolabeled
"heavy" water, 2H2O, enters the cyanelle and if,
subsequently, radiolabeled oxygen appears in cercozoan cytosol.
Answer: D
Paulinella chromatophora is one of the few cercozoans that is
autotrophic, carrying out aerobic photosynthesis with its two
elongated "cyanelles." The cyanelles are contained within
vesicles of the host cell, and each is derived from a cyanobacterium,
though not the same type of cyanobacterium that gave rise to the
chloroplasts of algae and plants.
62) A crucial photosynthetic gene of the cyanobacterium that
gave rise to the cyanelle is called psaE. This gene is present in the
nuclear genome of the cercozoan, but is not in the genome of the
cyanelle. This is evidence of
A) reciprocal mutations in the
cyanelle and nuclear genomes.
B) horizontal gene transfer from
bacterium to eukaryotes.
C) genetic recombination involving a
protist and an archaean.
D) the origin of photosynthesis in
protists.
E) transduction by a phage that infects both
prokaryotes and eukaryotes.
Answer: B
Paulinella chromatophora is one of the few cercozoans that is
autotrophic, carrying out aerobic photosynthesis with its two
elongated "cyanelles." The cyanelles are contained within
vesicles of the host cell, and each is derived from a cyanobacterium,
though not the same type of cyanobacterium that gave rise to the
chloroplasts of algae and plants.
63) What must occur for asexual reproduction to be successful in
P. chromatophora?
1. mitosis
2. S phase
3. meiosis
4. equal
distribution of cyanelles during cytokinesis
A) 1 only
B) 1 and 2
C) 1, 2, and 3
D) 1, 2,
and 4
E) 2, 3, and 4
Answer: D
Paulinella chromatophora is one of the few cercozoans that is
autotrophic, carrying out aerobic photosynthesis with its two
elongated "cyanelles." The cyanelles are contained within
vesicles of the host cell, and each is derived from a cyanobacterium,
though not the same type of cyanobacterium that gave rise to the
chloroplasts of algae and plants.
64) Including the membrane of the surrounding vesicle, how many
phospholipid (NOT lipopolysaccharide) bilayers should be found around
each cyanelle, and which one of these bilayers should have
photosystems embedded in it?
A) two; innermost
B) two;
outermost
C) three; innermost
D) three; middle
E)
three; outermost
Answer: A
Healthy individuals of Paramecium bursaria contain photosynthetic
algal endosymbionts of the genus Chlorella. When within their hosts,
the algae are referred to as zoochlorellae. In aquaria with light
coming from only one side, P. bursaria gathers at the well-lit side,
whereas other species of Paramecium gather at the opposite side. The
zoochlorellae provide their hosts with glucose and oxygen, and P.
bursaria provides its zoochlorellae with protection and motility. P.
bursaria can lose its zoochlorellae in two ways: (1) if kept in
darkness, the algae will die; and (2) if prey items (mostly bacteria)
are absent from its habitat, P. bursaria will digest its
zoochlorellae.
65) Which term most accurately describes the nutritional mode of
healthy P. bursaria?
A) photoautotroph
B) photoheterotroph
C) chemoheterotroph
D) chemoautotroph
E) mixotroph
Answer: E
Healthy individuals of Paramecium bursaria contain photosynthetic
algal endosymbionts of the genus Chlorella. When within their hosts,
the algae are referred to as zoochlorellae. In aquaria with light
coming from only one side, P. bursaria gathers at the well-lit side,
whereas other species of Paramecium gather at the opposite side. The
zoochlorellae provide their hosts with glucose and oxygen, and P.
bursaria provides its zoochlorellae with protection and motility. P.
bursaria can lose its zoochlorellae in two ways: (1) if kept in
darkness, the algae will die; and (2) if prey items (mostly bacteria)
are absent from its habitat, P. bursaria will digest its
zoochlorellae.
66) Which term accurately describes the behavior of Paramecium
species that lack zoochlorellae in an aquarium with light coming from
one side only?
A) positive chemotaxis
B) negative
chemotaxis
C) positive phototaxis
D) negative phototaxis
Answer: D
Healthy individuals of Paramecium bursaria contain photosynthetic
algal endosymbionts of the genus Chlorella. When within their hosts,
the algae are referred to as zoochlorellae. In aquaria with light
coming from only one side, P. bursaria gathers at the well-lit side,
whereas other species of Paramecium gather at the opposite side. The
zoochlorellae provide their hosts with glucose and oxygen, and P.
bursaria provides its zoochlorellae with protection and motility. P.
bursaria can lose its zoochlorellae in two ways: (1) if kept in
darkness, the algae will die; and (2) if prey items (mostly bacteria)
are absent from its habitat, P. bursaria will digest its
zoochlorellae.
67) Which term best describes the symbiotic relationship of
well-fed P. bursaria to their zoochlorellae?
A) mutualistic
B) commensal
C) parasitic
D) predatory
E) pathogenic
Answer: A
Healthy individuals of Paramecium bursaria contain photosynthetic
algal endosymbionts of the genus Chlorella. When within their hosts,
the algae are referred to as zoochlorellae. In aquaria with light
coming from only one side, P. bursaria gathers at the well-lit side,
whereas other species of Paramecium gather at the opposite side. The
zoochlorellae provide their hosts with glucose and oxygen, and P.
bursaria provides its zoochlorellae with protection and motility. P.
bursaria can lose its zoochlorellae in two ways: (1) if kept in
darkness, the algae will die; and (2) if prey items (mostly bacteria)
are absent from its habitat, P. bursaria will digest its
zoochlorellae.
68) The motility that permits P. bursaria to move toward a light
source is provided by
A) pseudopods.
B) a single flagellum
composed of the protein, flagellin.
C) a single flagellum
featuring the 9 + 2 pattern.
D) many cilia.
E) contractile vacuoles.
Answer: D
Healthy individuals of Paramecium bursaria contain photosynthetic
algal endosymbionts of the genus Chlorella. When within their hosts,
the algae are referred to as zoochlorellae. In aquaria with light
coming from only one side, P. bursaria gathers at the well-lit side,
whereas other species of Paramecium gather at the opposite side. The
zoochlorellae provide their hosts with glucose and oxygen, and P.
bursaria provides its zoochlorellae with protection and motility. P.
bursaria can lose its zoochlorellae in two ways: (1) if kept in
darkness, the algae will die; and (2) if prey items (mostly bacteria)
are absent from its habitat, P. bursaria will digest its
zoochlorellae.
69) 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?
A) abundant
light, no bacterial prey
B) abundant light, abundant bacterial
prey
C) no light, no bacterial prey
D) no light, abundant
bacterial prey
Answer: B
Healthy individuals of Paramecium bursaria contain photosynthetic
algal endosymbionts of the genus Chlorella. When within their hosts,
the algae are referred to as zoochlorellae. In aquaria with light
coming from only one side, P. bursaria gathers at the well-lit side,
whereas other species of Paramecium gather at the opposite side. The
zoochlorellae provide their hosts with glucose and oxygen, and P.
bursaria provides its zoochlorellae with protection and motility. P.
bursaria can lose its zoochlorellae in two ways: (1) if kept in
darkness, the algae will die; and (2) if prey items (mostly bacteria)
are absent from its habitat, P. bursaria will digest its
zoochlorellae.
70) A P. bursaria cell that has lost its zoochlorellae is
aposymbiotic. If aposymbiotic cells have population growth rates the
same as those of healthy, zoochlorella-containing P. bursaria in
well-lit environments with plenty of prey items, then such an
observation would be consistent with which type of relationship?
A) parasitic
B) commensalistic
C) toxic
D)
predator-prey
E) mutualistic
Answer: B
Healthy individuals of Paramecium bursaria contain photosynthetic
algal endosymbionts of the genus Chlorella. When within their hosts,
the algae are referred to as zoochlorellae. In aquaria with light
coming from only one side, P. bursaria gathers at the well-lit side,
whereas other species of Paramecium gather at the opposite side. The
zoochlorellae provide their hosts with glucose and oxygen, and P.
bursaria provides its zoochlorellae with protection and motility. P.
bursaria can lose its zoochlorellae in two ways: (1) if kept in
darkness, the algae will die; and (2) if prey items (mostly bacteria)
are absent from its habitat, P. bursaria will digest its
zoochlorellae.
71) 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?
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.
Answer: C
72) Plastids that are surrounded by more than two membranes are
evidence of
A) evolution from mitochondria.
B) fusion of
plastids.
C) origin of the plastids from archaea.
D)
secondary endosymbiosis.
E) budding of the plastids from the
nuclear envelope.
Answer: D
73) Biologists suspect that endosymbiosis gave rise to mitochondria
before plastids partly because
A) the products of photosynthesis
could not be metabolized without mitochondrial enzymes.
B) all
eukaryotes have mitochondria (or their remnants), whereas many
eukaryotes do not have plastids.
C) mitochondrial DNA is less
similar to prokaryotic DNA than is plastid DNA.
D) without
mitochondrial CO₂ production, photosynthesis could not occur.
E)
mitochondrial proteins are synthesized on cytosolic ribosomes, whereas
plastids utilize their own ribosomes.
Answer: B
74) Which group is incorrectly paired with its description?
A)
rhizariansmorphologically diverse group defined by DNA similarities
B) diatomsimportant producers in aquatic communities
C)
red algaeacquired plastids by secondary endosymbiosis
D)
apicomplexansparasites with intricate life cycles
E)
diplomonadsprotists with modified mitochondria
Answer: C
75) Which protists are in the same eukaryotic supergroup as land
plants?
A) green algae
B) dinoflagellates
C) red
algae
D) brown algae
E) both green algae and red algae
Answer: E
76) In life cycles with an alternation of generations, multicellular
haploid forms alternate with
A) unicellular haploid forms.
B) unicellular diploid forms.
C) multicellular haploid
forms.
D) multicellular diploid forms.
E) multicellular
polyploid forms.
Answer: D