Advertisement Upgrade to remove ads

he analytical approach to understanding the diversity and relatedness of both extant and extinct organisms is called _____. (eText Overview)

binomial nomenclature
taxonomy
systematics
evolution
phylogeny

systematics

What is the focus of the branch of biology called taxonomy? (eText Concept 26.1)

the environment
genetics
the classification of life-forms by their similarities and differences
evolution
the history of the field of biology

the classification of life-forms by their similarities and differences

The binomial system assigns to each organism a unique name that describes its _____. (eText Concept 26.1)

genus and species
order and family
evolutionary history
body plan and habitat
family and species

genus and species

The two-part format of the scientific name, referred to as binomial, ensures that _____. (eText Concept 26.1)

each species is assigned a unique name
systematists can easily specify the closest relatives of any species
each species has a name that is understandable regardless of language barriers among scientists
All of the listed responses are correct.
None of the listed responses is correct

All of the listed responses are correct

Which of the following is the correct taxonomic name for the African forest elephant? (eText Concept 26.1)

Loxodonta cyclotis
Loxodonta Cyclotis
Loxodonta Cyclotis
Loxodonta cyclotis
loxodonta cyclotis

Loxodonta cyclotis

A taxon _____. (eText Concept 26.1)

is a formal grouping at any given level
of one type of organism at one level is comparable to another type of organism at the same level
is a formal grouping in any level from phylum to species
is a species
is a clade

is a formal grouping at any given level

Rabbits and guinea pigs both belong to Class Mammalia. This means they must also both belong to _____. (eText Concept 26.1)

order Rodentia
family Caviidae
phylum Chordata
genus Cavia
All of the listed responses are correct.

phylum Chordata

Species A and species B are in the same phylum. Species A and species C, but not species B, are in the same order. From this information you can conclude that _____. (eText Concept 26.1)

species C could be in the same class as species A and B
all three species are members of the same genus
all three species are not members of the same phylum
species A and species B are in the same family
species B and species C share a less recent ancestor than do species A and B

species C could be in the same class as species A and B

What does a branch point in a phylogenetic tree represent? (eText Concept 26.1)

A branch point represents a place where one species branches off from another.
A branch point represents a gene duplication event.
A branch point represents a split between two phyla.
A branch point represents a point at which two evolutionary lineages split from a common ancestor.
A branch point represents the absolute time at which two evolutionary lineages split from a common ancestor.

A branch point represents a point at which two evolutionary lineages split from a
common ancestor.

Which of the following methods to establish phylogenetic relationships among organisms has been developed most recently? (eText Concept 26.2)

comparing embryonic development
comparing morphology (shape and structure)
comparing the component sequences of proteins and nucleic acids
comparing physiology (the functioning of structures and systems)
comparing behavioral patterns

comparing the component sequences of proteins and nucleic acids

The wings of a hummingbird and a bee are _____. (eText Concept 26.2)

phylogenetic
analogous
binomial
taxonomic
homologous

analogous

Which of the following would be the least useful in determining the relationships among various species? (eText Concept 26.2)

amino acid sequences of proteins
fossils
a comparison of DNA base sequences
homologous structures
analogous structures

analogous structures

Researchers can use molecular homologies to _____. (eText Concept 26.2)

estimate how long ago the common ancestor lived
hypothesize about the behavior of a common ancestor
reveal the number of mutations in a particular sequence that has occurred in each species since they diverged from a common ancestor
hypothesize about the morphological structures of a common ancestor
All of the listed responses are correct

reveal the number of mutations in a particular sequence that has occurred in each
species since they diverged from a common ancestor

A phylogenetic tree of bird families constructed by cladistic analysis would be a hypothesis about which of the following? (eText Concept 26.3)

analogous structures shared by various species
evolutionary relationships among bird families
characteristics shared by all bird families
families that look most alike
relative ages of living species of birds

evolutionary relationships among bird families

Looking at the table and phylogenetic tree in Figure 26.11, which of the following is a true statement? (eText Concept 26.3)

Four walking legs is a shared derived character in salamanders and a shared ancestral character in turtles.
Four walking legs is a derived character in leopards.
Four walking legs is a shared ancestral character in salamanders and a shared derived character in turtles.
Hinged jaws are derived from lampreys.
The amniotic egg is a derived character in salamanders.

Four walking legs is a shared derived character in salamanders and a shared
ancestral character in turtles.

Many researchers who study the kingdom Protista argue that all of these organisms should not be placed in the same kingdom, because these organisms could not have evolved from a common ancestor. In other words, they argue that the kingdom Protista is _____. (eText Concept 26.3)

heterophyletic
paraphyletic
polyphyletic
monophyletic
None of the listed responses is correct.

polyphyletic

Using cladistic analysis, a taxonomist wishes to construct a phylogenetic tree showing the relationships among various species of mammals. Which of the following would be the least useful for this purpose? (eText Concept 26.3)

DNA base sequences
the fact that all mammals have hair
data about skull bones
the fact that teeth vary among types of mammals
descriptions of various types of limbs (wings, legs, flippers, etc.)

the fact that all mammals have hair

Which statement below is true about an outgroup? (eText Concept 26.3)

The outgroup would be found at one of the highest branches of a phylogenetic tree.
The outgroup and ingroup display a mixture of shared and derived characters.
Outgroup comparison is based on the assumption that homologies present in both the outgroup and ingroup must be derived characters.
The outgroup should be less closely related to any members of the ingroup than they are to each other.
None of the listed responses is correct.

The outgroup should be less closely related to any members of the ingroup than they
are to each other.

Unlike a regular phylogenetic tree, phylogenetic trees with branch lengths proportional to time can be used to _____. (eText Concept 26.3)

hypothesize the relative relatedness between different taxa
represent the chronological time that has passed since two groups diverged from a common ancestor
reflect the number of evolutionary changes that have taken place in a lineage
reflect the rate of evolutionary change
tie polyphyletic clades to a common ancestor

represent the chronological time that has passed since two groups diverged from a
common ancestor

Which statement below is true of parsimonious trees? (eText Concept 26.3)

Given the rules of how DNA changes over time, a tree can be found that reflects the most likely sequence of evolutionary events.
Given the rules of how morphological traits change over time, a tree can be found that reflects the most likely sequence of evolutionary events.
Trees can be constructed that are parsimonious or the most likely, but not both at the same time.
The best tree requires the fewest evolutionary events to have occurred in the form of shared derived characters.
The best tree requires the fewest evolutionary events to have occurred in the form of shared ancestral characters.

The best tree requires the fewest evolutionary events to have occurred in the form of
shared derived characters.

Birds and mammals have a four-chambered heart, but most reptiles have a three-chambered heart. How does this fact affect the construction of phylogenetic trees for these groups? (eText Concept 26.3)

The most likely tree is always the most parsimonious.
This represents a problem with the principle of parsimony, rather than a problem with the analogy-homology issue.
It shows that the common ancestor of birds and mammals must have had a four-chambered heart.
The most likely tree is not always the most parsimonious.
None of the listed responses is correct.

The most likely tree is not always the most parsimonious.

If you wanted to determine the lineage of plants that have evolved on a relatively young archipelago—approximately 15,000 years old—what type of nucleic acid should you compare? (eText Concept 26.4)

mtDNA
nuclear DNA miRNA
rRNA
mRNA
tRNA

mtDNA

Paralogous genes _____. (eText Concept 26.4)

are responsible for the differences in beta hemoglobin in humans and mice
are passed from generation to generation in a straight line
can only diverge after speciation has taken place
cannot diverge in the same gene pool
result from gene duplication

result from gene duplication

What is the evolutionary significance of paralogous genes? (eText Concept 26.4)

They give the absolute time that two species diverged.
They increase the size of the genome and provide more opportunity for the evolution of novel characteristics.
The fact that many paralogous genes are found in vastly different organisms emphasizes the many biochemical and developmental pathways shared by all organisms.
They give the absolute time that the gene duplication occurred.
None of the listed responses is correct.

They increase the size of the genome and provide more opportunity for the
evolution of novel characteristics.

What is the evolutionary significance of orthologous genes? (eText Concept 26.4)

They always provide the evolutionary explanation with the maximum parsimony.
The high percentage of orthologous genes found in vastly different organisms emphasizes the many biochemical and developmental pathways shared by all organisms.
They increase the size of the genome and provide more opportunity for the evolution of novel characteristics.
They are passed from generation to generation in a straight line, and as such they change very little.
All of the listed responses are correct.

The high percentage of orthologous genes found in vastly different organisms
emphasizes the many biochemical and developmental pathways shared by all
organisms

Which of the following best summarizes the neutral theory? (eText Concept 26.5)

Differences in the rate of the clock in different genes are a function of how important each gene is.
Most harmful mutations are removed from a population quickly.
If a particular sequence of amino acids is critical for survival, most new mutations will be harmful and fewer will be neutral. These genes will change slowly over time.
Darwinian selection does not influence a lot of evolutionary change in genes and proteins because many of these changes do not affect fitness.
Most mutations lead to dramatic changes in the evolution of a species.

Darwinian selection does not influence a lot of evolutionary change in genes and
proteins because many of these changes do not affect fitness.

The idea of using molecules as clocks to time evolutionary events is very attractive, but there are many problems in actually applying the technique. What seems to be the best way to get reliable results? (eText Concept 26.5)

It is best to use a gene that is essential to survival because they change more slowly.
It is important to use one gene in which the changes are clearly neutral.
It is important to use as many genes as possible. With this approach, fluctuations in evolutionary rate will tend to average out.
It is important to use a gene that has been affected by natural selection to ensure that evolution will be observed.
All of the listed responses are correct.

It is important to use as many genes as possible. With this approach, fluctuations in
evolutionary rate will tend to average out.

By applying a molecular clock, researchers have proposed that the first HIV-1 M invasion into humans occurred in the _____. (eText Concept 26.5)

1980s
1890s
1950s
1830s
1930s

1930s

To which domain is the domain Eukarya (the domain to which humans belong) most closely related? (eText Concept 26.6)

Bacteria
It is not clear whether eukaryotes are more closely related to bacteria or archaea.
Fungi
Protista
Archaea

It is not clear whether eukaryotes are more closely related to bacteria or archaea.

Universal phylogenetic trees built from different genes sometimes give inconsistent results. What basic assumption on which phylogenetic trees are based has probably been violated during the history of life? (eText Concept 26.6)

Genes are passed vertically from one generation to the next.
The greater the difference in gene sequences, the longer two species have diverged.
Analogous traits come about because of convergent evolution.
Homologous traits come about because of common ancestry.
Genes are often passed from one organism to another without the occurrence of reproduction.

Genes are passed vertically from one generation to the next.

Why is salt a good preservative to use for foods such as pork and fish? (eText Concept 27.1)

Salt breaks down the chitin contained in the cell walls of prokaryotes.
Salt is a toxin to prokaryotic cells and leads to their death.
Prokaryotes living in the food products will take in excess water and explode.
Prokaryotic cells living in the food will shrink from their cell walls, impacting their ability to reproduce.
Salt breaks down the peptidoglycan found in the capsule of prokaryotes.

Prokaryotic cells living in the food will shrink from their cell walls, impacting their ability
to reproduce

Gram-negative bacteria have _____ peptidoglycan than gram-positive cells, and their cell walls are _____ complex structurally. (eText Concept 27.1)

more ... more
more ... less
less ... less
less ... more
None of the listed responses is correct.

less ... more

A gram-negative cell wall consists of _____. (eText Concept 27.1)

cholesterol and peptidoglycan
a thin layer of peptidoglycan surrounded by a capsule
a thin layer of peptidoglycan surrounded by an outer membrane containing lipopolysaccharides
peptidoglycan and cellulose
a thick layer of peptidoglycan surrounded by an outer membrane containing lipopolysaccharides

a thin layer of peptidoglycan surrounded by an outer membrane containing
lipopolysaccharides

Bacteria that _____ tend to have abundant internal membranes. (eText Concept 27.1)

have flagella
are gram-negative
are photosynthetic
are pathogenic
All of the listed responses are correct.

are photosynthetic

Bacterial cells, but not eukaryotic cells, possess _____. (eText Concept 27.1)

photosynthetic pigments
membrane-enclosed organelles
cell walls
a nucleoid with a circular chromosome
a "9 + 2" arrangement of microtubules

a nucleoid with a circular chromosome

Bacterial flagella have a very complex structure composed of 42 distinct proteins. What is the most likely explanation for the evolution of these complex structures? (eText Concept 27.1)

Early bacterial species needed to be able to locomote and thus developed complex flagella to facilitate this motility.
endosymbiosis
Flagella evolved as extensions of other bacterial appendages such as pili and fimbriae.
They evolved from earlier, simpler organisms.
exaptation

exaptation

The bacteria that cause tetanus can be killed only by prolonged heating at temperatures considerably above boiling. This suggests that these bacteria _____. (eText Concept 27.1)

secrete endotoxins
have cell walls containing peptidoglycan
are autotrophic
protect themselves by secreting antibiotics
produce endospores

produce endospores

Plasmids _____. (eText Concept 27.2)

are transferred from one bacterium to another by conjugation
often contain antibiotic resistance genes
replicate independently of the main chromosome
allow bacteria to survive adverse conditions
All of the listed responses are correct.

All of the listed responses are correct.

How is it possible that as many as 9 million mutations can arise each day in the E. coli inhabiting one human? (eText Concept 27.2)

Transformation is occurring.
The interior of the human colon is particularly mutagenic.
Conjugation is occurring.
The mathematics of large population size and rapid reproduction rate combine to produce many mutations without a particularly high mutation rate.
E. coli have a very high mutation rate.

The mathematics of large population size and rapid reproduction rate combine to
produce many mutations without a particularly high mutation rate.

In the absence of meiosis and sexual reproduction, what general process allows genetic recombination among prokaryotes? (eText Concept 27.2)

horizontal gene transfer
transduction
mutation
evolution
chemoautotrophy

horizontal gene transfer

Which statement about transformation is true? (eText Concept 27.2)

It requires transport of DNA by a virus.
Although common in laboratory populations of bacteria, it does not play an important role in natural bacterial populations.
It is a very rare phenomenon that happens by chance.
It requires movement of DNA through a pilus.
It can be facilitated by cell-surface proteins that recognize compatible DNA

It can be facilitated by cell-surface proteins that recognize compatible DNA.

An F+ bacterial cell _____. (eText Concept 27.2)

has many antibiotic resistance genes
acts as a receptor during conjugation
transfers DNA by way of transduction
Uses fimbriae to transfer DNA
acts as a donor during conjugation

acts as a donor during conjugation

Which of the following is true about R plasmids? (eText Concept 27.2)

They can only carry one resistance gene for resistance to one antibiotic.
They can be transferred from one bacterium to another via conjugation.
They can carry several resistance genes.
Both the first and second statements are correct.
Both the second and third answers are correct.

Both the second and third answers are correct.

Bacteria that use light for their energy source and CO2 for their carbon source are called _____. (eText Concept 27.3)

photoheterotrophs
chemoautotrophs
photoautotrophs
chemoheterotrophs
photochemoheterotrophs

photoautotrophs

In an experiment, a microbiologist put equal numbers of each of the following organisms into a flask of sterile broth, consisting mostly of sugar and a few amino acids. She then placed the flask in the dark. Which of the organisms would be most likely to survive? (eText Concept 27.3)

cyanobacteria
photoautotrophs
chemoheterotrophic bacteria
thermoacidophilic bacteria
photoheterotrophs

chemoheterotrophic bacteria

The Desulfovibrio bacterium breaks down organic matter (which it must have) and uses sulfate (not oxygen) as an electron acceptor. As a result, it produces hydrogen sulfide (H2S), accounting for the "rotten egg" smell of swamp muck. Oxygen is a deadly poison to Desulfovibrio. We would call Desulfovibrio a(n) _____. (eText Concept 27.3)

facultatively aerobic chemoheterotroph
There is insufficient information to answer this question.
obligately anaerobic chemoheterotroph
obligately anaerobic chemoautotroph
facultatively anaerobic chemoautotroph

obligately anaerobic chemoheterotroph

Choose the list below that contains the substances required by typical nitrogen-fixing cyanobacteria. (eText Concept 27.3)

carbon, nitrogen, light, water, and some minerals
carbon dioxide, ammonium, water, light, and some minerals
carbon dioxide, nitrogen, water, light, and some minerals
carbon dioxide, sulfur, light, water, and some minerals
oxygen, sulfur, light, water, and some minerals

carbon dioxide, nitrogen, water, light, and some minerals

What is the role of heterocysts in a cyanobacterial filament? (eText Concept 27.3)

They carry out only nitrogen fixation.
They oxidize inorganic substances to obtain energy.
They carry out only photosynthesis.
They carry out photosynthesis and nitrogen fixation.
They store endospores.

They carry out only nitrogen fixation.

Biofilms are an example of _____. (eText Concept 27.3)

multicellularity in prokaryotes
sites of horizontal gene transfer among prokaryotes
sites of intense nitrogen fixation by prokaryotes
metabolic cooperation among prokaryotic species
scientific videos

metabolic cooperation among prokaryotic species

Portions of the genomes of certain prokaryotic species are very similar to portions of the genomes of distantly related prokaryotes. The process that most likely accounts for this genetic similarity is _____. (eText Concept 27.4)

genetic variation arising from binary fission
identical mutations occurring independently in these distantly related lineages
convergent evolution
horizontal gene transfer
genetic variation arising from meiosis

horizontal gene transfer

Which subgroup of proteobacteria contains many species that are closely associated with eukaryotic hosts in mutualistic or parasitic relationships? (eText Concept 27.4)

epsilon
beta
gamma
delta
alpha

alpha

Which subgroup of proteobacteria contains many species that are predators of other bacteria? (eText Concept 27.4)

alpha
delta
gamma
epsilon
beta

delta

Which group of bacteria is unusual in that they lack peptidoglycan in their cell walls? (eText Concept 27.4)

chlamydias
gram-negative bacteria
spirochetes
cyanobacteria
epsilon proteobacteria

chlamydias

Which of the following is a difference between bacteria and archaea? (eText Concept 27.4)

Many archaea are extremophiles, but no bacteria are.
Archaea are unicellular, and bacteria are colonial.
Only bacteria have circular chromosomes.
They have different chemicals in their cell membranes and cell walls.
Bacteria are autotrophic, and archaea are heterotrophic.

End of Question 24

They have different chemicals in their cell membranes and cell walls.

Which of the following statements about cyanobacteria is true? (eText Concept 27.4)

They are the only prokaryotes that perform plantlike, oxygenic photosynthesis.
Some are single cells, whereas others live in filamentous colonies.
Some species may carry on nitrogen fixation.
It can be said that nitrogen-fixing cyanobacteria are the most self-sufficient of all organisms.
All of the listed responses are correct.

All of the listed responses are correct.

Prokaryotes found inhabiting the Great Salt Lake would be _____. (eText Concept 27.4)

extremophiles
cyanobacteria
extreme halophiles
extreme thermophiles
methanogens

extreme halophiles

Which of the following groups of prokaryotes is classified as a member of the domain Archaea? (eText Concept 27.4)

botulism-causing prokaryotes
gram-negative bacteria
methanogens
cyanobacteria
spirochetes

methanogens

Which clade of archaea includes most of the extreme thermophiles? (eText Concept 27.4)

Korarchaeota
Euryarchaeota
Nanoarchaeota
Crenarchaeota
Extremophiles

Crenarchaeota

Prokaryotes are completely indispensable to which chemical cycle? (eText Concept 27.5)

carbon
nitrogen
phosphorus
water
sulfur

nitrogen

A type of ecological relationship called _____ involves one organism living at the expense of another organism. (eText Concept 27.5)

mutualism
symbiosis
commensalism
parasitism
phoresis

parasitism

Which example below is a correct statement about Bacteroides thetaiotaomicron, a bacterium that lives in the human intestines? (eText Concept 27.6)

The bacteria have a parasitic relationship with the human body.
The bacteria directly create a network of intestinal blood vessels necessary to absorb food.
Many pathogenic strains of B. thetaiotaomicron have emerged.
The bacteria have a mutualistic relationship with the human body.
The bacteria have a commensal relationship with the human body.

The bacteria have a mutualistic relationship with the human body.

icks that live on deer and field mice are responsible for spreading the bacterium _____, which causes _____. (eText Concept 27.6)

Clostridium botulinum ... botulism
Salmonella typhi ... typhoid fever
Vibrio cholerae ... cholera
Mycobacterium tuberculosis ... tuberculosis
Borrelia burgdorferi ... Lyme disease

Borrelia burgdorferi ... Lyme disease

Which statement is true regarding cholera? (eText Concept 27.6)

People are apt to come down with cholera after eating improperly canned foods.
The disease is caused by typically harmless enteric bacteria.
Its symptoms are caused by an exotoxin that stimulates intestinal cells to release chloride ions into the gut.
The symptoms begin when Vibrio cholerae die and endotoxins are released from the cell walls.
It is the most widespread pest-carried disease in the United States.

Its symptoms are caused by an exotoxin that stimulates intestinal cells to release
chloride ions into the gut.

Scientists hypothesize that the O157:H7 strain of E. coli is so different from the K-12 strain because of _____. (eText Concept 27.6)

the frequent abuse of antibiotics used to treat this bacteria
the high number of mutations that occur in this type of bacteria
the higher-than-average rate of binary fission that occurs in this type of bacteria
the immense number of plasmids associated with this group of bacteria
horizontal gene transfer over many years, most likely through the action of bacteriophages

horizontal gene transfer over many years, most likely through the action of
bacteriophages

Which statement about prokaryotes is true? (eText Concept 27.6)

Prokaryotes are not useful in genetic engineering because their DNA is so different from that of eukaryotes.
It is important to try and rid your body of all prokaryotes.
The vast majority of prokaryotes are pathogenic.
Prokaryotes are widely used for bioremediation.
Prokaryotes have no industrial uses.

Prokaryotes are widely used for bioremediation

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). Consequently, the morphological similarities of these two species are probably due to
_______
A)
sexual selection.
B)
inheritance of shared derived characters.
C)
inheritance of acquired characteristics.
D)
possession of analogous structures.
E)
possession of shared primitive characters.

D)
possession of analogous structures.

The term that is most appropriately associated with clade is
_______
A)
monophyletic.
B)
paraphyletic.
C)
polyphyletic.

A)
monophyletic.

When using a cladistic approach to systematics, which of the following is considered most important for classification?
_______
A)
the number of homoplasies
B)
overall phenotypic similarity
C)
analogous primitive characters
D)
shared derived characters
E)
shared primitive characters

D)
shared derived characters

Phylogenetic hypotheses (such as those represented by phylogenetic trees) are strongest when
_______
A)
they are based on a single DNA sequence that seems to be a shared derived sequence.
B)
they are supported by more than one kind of evidence, such as when fossil evidence corroborates molecular evidence.
C)
they are accepted by the foremost authorities in the field, especially if they have won Nobel Prizes.
D)
each clade is defined by a single derived character.
E)
they are based on amino acid sequences from homologous proteins, as long as the genes that code for such proteins contain no introns.

B)
they are supported by more than one kind of evidence, such as when fossil evidence corroborates molecular evidence.

Which of these is the most common compound in the cell walls of gram-positive bacteria?
_______
A)
peptidoglycan
B)
protein
C)
cellulose
D)
lipopolysaccharide
E)
lignin

A)
peptidoglycan

Which statement about the genomes of prokaryotes is correct?
_______
A)
Prokaryotic genomes are diploid throughout most of the cell cycle.
B)
The prokaryotic chromosome is not contained within a nucleus but, rather, is found at the nucleoid region.
C)
Prokaryotic cells have multiple chromosomes, "packed" with a relatively large amount of protein.
D)
Prokaryotic genomes are composed of linear DNA (that is, DNA existing in the form of a line with two ends).
E)
Prokaryotic chromosomes are sometimes called plasmids.

B)
The prokaryotic chromosome is not contained within a nucleus but, rather, is found at the nucleoid region.
C)

Regarding prokaryotic reproduction, which statement is correct?
_______
A)
Prokaryotes feature the union of haploid gametes, as do eukaryotes.
B)
Prokaryotes exchange some of their genes by conjugation, the union of haploid gametes, and transduction.
C)
Prokaryotes skip sexual life cycles because their life cycle is too short.
D)
Mutation is a primary source of variation in prokaryote populations.
E)
Prokaryotes form gametes by meiosis.

D)
Mutation is a primary source of variation in prokaryote populations

Modes of obtaining nutrients, used by at least some bacteria, include all of the following except
______
A)
heteroautotrophy.
B)
chemoheterotrophy.
C)
photoautotrophy.
D)
chemoautotrophy.
E)
photoheterotrophy

A)
heteroautotrophy.

Which of the following traits do archaeans 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)
3 only
B)
2 and 4
C)
1 only
D)
1 and 3
E)
2 and 3

E)
2 and 3

Assuming that each of these possesses a cell wall, which prokaryotes should be expected to survive in hypertonic (high salt) environments?
______
A)
extreme thermophiles
B)
methanogens
C)
nitrogen-fixing bacteria that live in root nodules
D)
cyanobacteria
E)
extreme halophiles

E)
extreme halophiles

Protists are alike in that all are
______
A)
unicellular.
B)
monophyletic.
C)
symbionts.
D)
eukaryotic.
E)
autotrophic

D)
eukaryotic.

According to the endosymbiotic theory of the origin of eukaryotic cells, how did mitochondria originate?
______
A)
from engulfed, originally free-living prokaryotes
B)
when a protoeukaryote engaged in a symbiotic relationship with a protobiont
C)
from the nuclear envelope folding outward and forming mitochondrial membranes
D)
by secondary endosymbiosis
E)
from infoldings of the plasma membrane, coupled with mutations of genes for proteins in energy-transfer reactions

A)
from engulfed, originally free-living prokaryotes

Which organisms represent the common ancestor of all photosynthetic plastids found in eukaryotes?
______
A)
autotrophic euglenids
B)
dinoflagellates
C)
cyanobacteria
D)
diatoms
E)
red algae

C)
cyanobacteria

Which of the following pairs of protists and their characteristics is mismatched?
______
A)
ciliates : red tide organisms
B)
apicomplexans : internal parasites
C)
entamoebas : ingestive heterotrophs
D)
golden algae : planktonic producers
E)
euglenozoans : unicellular flagellates

A)
ciliates : red tide organisms

A snail-like, coiled, porous test (shell) of calcium carbonate is characteristic of which group?
______
A)
gymnamoebas
B)
ciliates
C)
foraminiferans
D)
diatoms
E)
radiolarians

C)
foraminiferans

The chloroplasts of all of the following are derived from ancestral red algae, except those of
______
A)
golden algae.
B)
brown algae.
C)
green algae.
D)
diatoms.
E)
dinoflagellates.

C)
green algae.

The legless condition that is observed in several groups of extant reptiles is the result of
______
A)
individual lizards adapting to a fossorial (living in burrows) lifestyle during their lifetimes.
B)
a shared adaptation to an arboreal (living in trees) lifestyle.
C)
their common ancestor having been legless.
D)
several instances of the legless condition arising independently of each other.

D)
several instances of the legless condition arising independently of each other.

Which of these illustrates the correct representation of the binomial scientific name for the African lion?
______
A)
Panthera leo
B)
Panthera leo
C)
Panthera Leo
D)
panthera leo
E)
Panthera leo

B)
Panthera leo

Which of the following pairs are the best examples of homologous structures?
______
A)
owl wing and hornet wing
B)
Australian mole and North American mole
C)
bat forelimb and bird wing
D)
porcupine quill and cactus spine
E)
bat wing and human hand

E)
bat wing and human hand

Shared derived characters are most likely to be found in taxa that are
______
A)
monophyletic.
B)
paraphyletic.
C)
polyphyletic.

A)
monophyletic.

If birds are excluded from the class Reptilia, the term that consequently describes the class Reptilia is
______
A)
paraphyletic.
B)
monophyletic.
C)
polyphyletic

A)
paraphyletic.

Mycoplasmas are bacteria that lack cell walls. On the basis of this structural feature, which statement concerning mycoplasmas should be true?
______
A)
They are gram-negative.
B)
They possess typical prokaryotic flagella.
C)
They lack a cell membrane as well.
D)
They undergo ready fossilization in sedimentary rock.
E)
They are subject to lysis in hypotonic conditions.

E)
They are subject to lysis in hypotonic conditions.

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)
are unable to metabolize the glucose or fructose, and thus starve to death.
B)
undergo death by lysis.
C)
are obligate anaerobes.
D)
undergo death by plasmolysis.
E)
are unable to swim through these thick and viscous materials.

D)
undergo death by plasmolysis.

Which of these statements about prokaryotes is correct?
______
A)
Genetic variation in bacteria is not known to occur, nor should it occur, because of their asexual mode of reproduction.
B)
They divide by binary fission, without mitosis or meiosis.
C)
Their genetic material is confined within a nuclear envelope.
D)
The persistence of bacteria throughout evolutionary time is due to their genetic homogeneity (i.e., sameness).
E)
Bacterial cells conjugate to mutually exchange genetic material

B)
They divide by binary fission, without mitosis or meiosis.

Match the numbered terms to the descriptions that follow. For each item, choose all appropriate terms, but only appropriate terms.
1. autotroph
2. heterotroph
3. phototroph
4. chemotroph

an organism that obtains its energy from chemicals
______
A)
2 only
B)
1 only
C)
3 only
D)
1 and 4
E)
4 only

E)
4 only

Carl Woese and collaborators identified two major branches of prokaryotic evolution. What was the basis for dividing prokaryotes into two domains?
______
A)
metabolic characteristics such as chemoautotrophy and photosynthesis
B)
ecological characteristics such as the ability to survive in extreme environments
C)
metabolic characteristics such as the production of methane gas
D)
microscopic examination of staining characteristics of the cell wall
E)
genetic characteristics such as ribosomal RNA sequences

E)
genetic characteristics such as ribosomal RNA sequences

If archaeans are more closely related to eukaryotes than to bacteria, then which of the following is a reasonable prediction?
______
A)
Archaean ribosomes should be larger than typical prokaryotic ribosomes.
B)
Archaeans should lack cell walls.
C)
Archaean DNA should have no introns.
D)
Archaean DNA should be single-stranded.
E)
Archaean chromosomes should have no protein bonded to them.

A)
Archaean ribosomes should be larger than typical prokaryotic ribosomes.

An individual mixotroph loses its plastids, yet continues to survive. Which of the following most likely accounts for its continued survival?
______
A)
It engulfs organic material by phagocytosis or by absorption.
B)
It has an endospore.
C)
It is protected by a siliceous case.
D)
It must have gained extra mitochondria when it lost its plastids.
E)
It relies on photosystems that float freely in its cytosol.

A)
It engulfs organic material by phagocytosis or by absorption.

Why have protists been "mixed in" with plants, animals, and fungi under the hypothesis that groups eukaryotes into five supergroups? (eText Overview)

Many protists are more closely related to plants, animals, or fungi than they are to each other.
The discovery of very small protists, similar in size to prokaryotes, has made the former classification scheme obsolete.
Recent evidence makes it clear that the former kingdom Protista was paraphyletic.
The discovery that protists had organelles made it clear that they should be grouped with other eukaryotes.
Both the first and third answers are correct.

Both the first and third answers are correct.

The placement of all protists in one kingdom caused dissatisfaction among taxonomists mainly because _____. (eText Concept 28.1)

protist cells are more similar to prokaryotic cells than to eukaryotic cells
various pieces of evidence indicate that the kingdom Protista cannot be monophyletic
various pieces of evidence indicate that the Protista are not polyphyletic
some protists are autotrophic and others are heterotrophic
All of the listed responses are correct.

various pieces of evidence indicate that the kingdom Protista cannot be
monophyletic

Which of the following is one of the main weaknesses of the proposed classification scheme in which all eukaryotes are divided into five supergroups? (eText Concept 28.1)

It does not take into account the importance of endosymbiosis.
It does not explain the extra membranes found in some plastids.
It shows all five supergroups diverging simultaneously from a common ancestor.
It postulates that photosynthetic protists arose by way of endosymbiosis.
It does not account for "amitochondriate" protists.

It shows all five supergroups diverging simultaneously from a common ancestor.

Organisms are classified as Excavata based on _____. (eText Concept 28.2)

their lack of true mitochondria
the presence of pseudopodia
their mode of obtaining energy
their origin by secondary endosymbiosis of a red alga
morphological studies of the cytoskeleton

morphological studies of the cytoskeleton

Which example below is a characteristic shared by diplomonads and parabasalids? (eText Concept 28.2)

Both lack plastids.
Both have a single flagellum.
Both are adapted to aerobic environments.
Both have two nuclei.
Both lack mitochondria

Both lack plastids.

How do trypanosomes withstand the attack of a host's immune system? (eText Concept 28.2)

They specifically poison helper T cells.
The molecular composition of their surface changes continually.
They live only in the cerebrospinal fluid, where the immune system can't reach them.
They reproduce so fast that they can compensate for the death rate caused by the immune system.
All of the listed responses are correct.

The molecular composition of their surface changes continually.

Which of these groups includes photosynthetic unicellular organisms with flagella and contractile vacuoles? (eText Concept 28.2)

apicomplexans
dinoflagellates
ciliates
diatoms
euglenids

euglenids

Although controversial, chromalveolates are proposed as a clade whose common ancestor _____. (eText Concept 28.3)

was a multinucleate mass
was the first mixotroph
engulfed a photosynthetic red alga in a secondary endosymbiosis event
engulfed an alpha proteobacterium in a primary endosymbiosis event
lost its mitochondria

engulfed a photosynthetic red alga in a secondary endosymbiosis event

Apicomplexans are currently assigned to the chromalveolates because _____. (eText Concept 28.3)

they have life cycles with both sexual and asexual stages
they have true roots, stems, and leaves
they are parasites
the apicoplast, a modified plastid, appears to be of red algal origin
Both the first and third responses are correct.

the apicoplast, a modified plastid, appears to be of red algal origin

In many types of protist life cycles, the union of two gametes that results in a diploid zygote is called _____. (eText Concept 28.3)

syngamy
mixotrophy
alternation of generations
endosymbiosis
blooming

syngamy

What do a carnivorous dinoflagellate, a parasitic apicomplexan, and a ciliate have in common? (eText Concept 28.3)

All three are parasitic on other species of organisms.
All three form colonies of cells.
All three are heterotrophic and autotrophic.
All three have sacs known as alveoli just beneath their plasma membranes.
All three are photosynthetic.

All three have sacs known as alveoli just beneath their plasma membranes.

Which organisms are capable of producing a "red tide"? (eText Concept 28.3)

dinoflagellates
euglenids
chrysophytes (diatoms)
sporozoans
None of the listed responses is correct

dinoflagellates

Which of these groups includes species that produce a substance that is toxic to humans? (eText Concept 28.3)

diatoms
ciliates
euglenids
apicomplexans
dinoflagellates

dinoflagellates

Which of these groups includes parasitic unicellular organisms with a complex of organelles specialized for penetrating host cells and tissues? (eText Concept 28.3)

dinoflagellates
apicomplexans
euglenoids
diatoms
ciliates

apicomplexans

Which of these groups is characterized by cells that have more than one nucleus? (eText Concept 28.3)

euglenids
apicomplexans
diatoms
dinoflagellates
ciliates

ciliates

How do ciliates generate genetic variation? (eText Concept 28.3)

binary fission
conjugation
asexual reproduction
alternation of generations
None of the listed responses is correct.

conjugation

Which protists were once categorized as fungi due to their multinucleate filaments that resemble hyphae? (eText Concept 28.3)

dinoflagellates
golden algae
parabasalids
oomycetes
stramenopiles

oomycetes

_____ is a protist that causes late blight of potatoes and was responsible for the Irish potato famine of the 19th century. (eText Concept 28.3)

Laminaria
Dinobryon
Dictyostelium discoideum
Phytophthora infestans
Entamoeba

Phytophthora infestans

Which of these groups includes unicellular organisms that, due to the structure of their cell walls, can withstand pressures equal to the pressure under each leg of a table supporting an elephant? (eText Concept 28.3)

ciliates
dinoflagellates
euglenids
apicomplexans
diatoms

diatoms

Which characteristic is shared by most diatoms, golden algae, and brown algae at least at some stage of their life cycles? (eText Concept 28.3)

They all have flagella with numerous fine, hairlike projections.
All are autotrophs.
All are stramenopiles.
All of the listed responses are correct.
None of the listed responses is correct.

All of the listed responses are correct

The general term given to a plantlike body that lacks true stems, leaves, and roots and that shows little tissue differentiation is _____. (eText Concept 28.3)

gametophyte
stipe
thallus
holdfast
rhizoid

thallus

What is the purpose of the "floats" in some brown algae? (eText Concept 28.3)

protecting the seaweed from drying out
facilitating photosynthesis
anchoring the seaweed
protecting seaweed from crashing waves
absorbing iodine and carbon dioxide from seawater

facilitating photosynthesis

Which of the following organisms is commercially harvested to extract algin from their cell walls? (eText Concept 28.3)

brown algae
golden algae
diatoms
marine green algae, such as Ulva
dinoflagellates

brown algae

What role do diatoms play in the global carbon balance affecting global warming? (eText Concept 28.3)

Diatoms release large amounts of methane, a greenhouse gas, into the atmosphere.
During a bloom, diatom populations increase rapidly, providing many more photosynthetic organisms to the plankton population.
During a bloom, diatom populations may increase rapidly. If many diatoms die and sink to the bottom without being eaten, they effectively pump carbon dioxide out of the atmosphere.
Diatoms release large amounts of carbon dioxide, a greenhouse gas, into the atmosphere.
Diatomaceous earth can be used to filter carbon dioxide from the atmosphere.

During a bloom, diatom populations may increase rapidly. If many diatoms die and
sink to the bottom without being eaten, they effectively pump carbon dioxide out of
the atmosphere.

On some areas of the seafloor, one could observe an "ooze" that is hundreds of meters thick. What creates this ooze? (eText Concept 28.4)

the tests of dead diatoms
the decaying porous shells of forams
the gel-forming polysaccharides secreted by brown and red algae
colonies of plasmodial slime molds
the tests of dead radiolarians

the tests of dead radiolarians

Many species of red algae are adapted to deeper water due to the fact that _____. (eText Concept 28.5)

their red pigments readily absorb red light
they grow long stalks with floats on the ends to hold the blades near the surface
their cell walls are adapted to withstand bright light
their photosynthetic pigments efficiently absorb blue and green light
All of the listed responses are correct.

their photosynthetic pigments efficiently absorb blue and green light

The red algae are characterized by _____. (eText Concept 28.5)

multinucleated portions
a red coloration in all their species
population explosions known as "red tides"
especially diverse life cycles
flagellated gametes that do not require water for fertilization to occur

especially diverse life cycles

Which of the following groups of algae is/are most closely related to land plants? (eText Concept 28.5)

blue-green algae
brown algae
red algae
green algae
All of the listed responses are correct.

green algae

In lab class, a plasmodial slime mold is used as a demonstration organism. One of the students does not understand why this organism is not considered multicellular. How would you explain it to her? (eText Concept 28.6)

The distinct cells that make up the plasmodium do not cooperate, so they do not represent a truly multicellular organism.
The plasmodium is undivided by membranes and contains many diploid nuclei; therefore, it is not technically multicellular.
The nuclei found in the plasmodium of a plasmodial slime mold are diploid.
Plasmodial slime molds are not able to reproduce sexually, so therefore they are not truly multicellular.
Multicellular organisms are seen only in the kingdoms Animalia and Plantae.

The plasmodium is undivided by membranes and contains many diploid nuclei;
therefore, it is not technically multicellular

o which supergroup do amoebas belong? (eText Concept 28.6)

Rhizaria
Chromalveolates
Apicomplexans
Unikonta
None of the listed responses is correct.

None of the listed responses is correct.

It is estimated that protists perform up to what percentage of the world's photosynthesis? (eText Concept 28.7)

5%
10%
40%
50%
30%

30%

Hypermastigotes are important endosymbionts that live in the guts of _____. (eText Concept 28.7)

humans
rabbits
termites
cattle
ants

termites

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set