Study Guide 22-27MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) With what other idea of his time was Cuvier's theory of catastrophism most in conflict? 1)A) uniformitarianismB) the fixity of speciesC) island biogeographyD) gradualismE) the scala naturae

2) The role that humans play in artificial selection is to 2)A) perform artificial insemination.B) create the genetic variants, which nature then selects.C) determine who lives and who dies.D) train organisms to breed more successfully.E) choose which organisms breed, and which do not.

3) If Darwin had been aware of genes, and of their typical mode of transmission to subsequentgenerations, with which statement would he most likely have been in agreement?

3)

A) If natural selection can change one gene's frequency in a population over the course ofgenerations then, given enough time and enough genes, natural selection can cause sufficientgenetic change to produce new species from old ones.

B) If an individual acquires new genes by engulfing, or being infected by, another organism,then a new genetic species will be the result.

C) If an individual's somatic cell genes change during its lifetime, making it more fit, then it willbe able to pass these genes on to its offspring.

D) A single mutation in a single gene in a single gamete will, if perpetuated, produce a newspecies within just two generations.

4) If one wanted to find the largest number of endemic species, one should visit which of thefollowing geological features (assuming each has existed for several millions of years)?

4)

A) an extensive mountain rangeB) a shallow estuary on a warm-water coastC) a midcontinental grassland with extreme climatic conditionsD) an isolated ocean island in the tropics

5) During a study session about evolution, one of your fellow students remarks, "The giraffe stretchedits neck while reaching for higher leaves; its offspring inherited longer necks as a result." Whichstatement is most likely to be helpful in correcting this student's misconception?

5)

A) Disuse of an organ may lead to its eventual disappearance.B) Characteristics acquired during an organism's life are generally not passed on through genes.C) If the giraffes did not have to compete with each other, longer necks would not have been

passed on to the next generation.D) Spontaneous mutations can result in the appearance of new traits.E) Only favorable adaptations have survival value.

6) Charles Darwin was the first person to propose 6)A) a mechanism for how evolution occurs.B) a mechanism for evolution that was supported by evidence.C) that evolution occurs.D) that population growth can outpace the growth of food resources.E) that Earth is older than a few thousand years.

1

7) Structures as different as human arms, bat wings, and dolphin flippers contain many of the samebones, these bones having developed from very similar embryonic tissues. How do biologistsinterpret these similarities?

7)

A) by identifying the bones as being homologous structuresB) by proposing that humans, bats, and dolphins share a common ancestorC) by the principle of convergent evolutionD) Three of the statements above are correct.E) Two of the statements above are correct.

8) Which of the following is not an observation or inference on which natural selection is based? 8)A) Poorly adapted individuals never produce offspring.B) Species produce more offspring than the environment can support.C) Individuals whose characteristics are best suited to the environment generally leave more

offspring than those whose characteristics are less well suited.D) There is heritable variation among individuals.E) Only a fraction of an individual's offspring may survive.

9) It has been observed that organisms on islands are different from, but closely related to, similarforms found on the nearest continent. This is taken as evidence that

9)

A) common environments are inhabited by the same organisms.B) island forms and mainland forms descended from common ancestors.C) the islands were originally part of the continent.D) island forms and mainland forms have identical gene pools.E) the island forms and mainland forms are converging.

10) Which of the following must exist in a population before natural selection can act upon thatpopulation?

10)

A) sexual reproductionB) variation among individuals caused by environmental factorsC) genetic variation among individualsD) Three of the responses are correct.E) Two of the responses are correct.

11) The rise of methicillin-resistant Staphylococcus aureus (MRSA) can be considered to be an exampleof artificial selection because

11)

A) humans purposefully raise MRSA in large fermenters in an attempt to make the bacteriaever-more resistant.

B) Humans are becoming resistant to bacteria by taking methicillin.C) humans synthesize methicillin and create environments in which bacteria frequently come

into contact with methicillin.D) S. aureus is cultivated by humans to replenish the soil with nutrients.

12) Which of the following statements best describes theories? 12)A) They are supported by, and make sense of, many observations.B) They cannot be tested because the described events occurred only once.C) They are nearly the same things as hypotheses.D) They are predictions of future events.

2

13) What is true of pseudogenes? 13)A) They are unrelated genes that code for the same gene product.B) They are vestigial genes.C) They are the same things as introns.D) They are composed of RNA, rather than DNA.

14) What must be true of any organ that is described as vestigial? 14)A) It must be both homologous and analogous to some feature in an ancestor.B) It must be analogous to some feature in an ancestor.C) It need be neither homologous nor analogous to some feature in an ancestor.D) It must be homologous to some feature in an ancestor.

The following questions refer to Figure 22.1, which shows an outcrop of sedimentary rock whose strata are labeled A D.

Figure 22.1

15) If x indicates the location of fossils of two closely related species, then fossils of their most-recentcommon ancestor are most likely to occur in which stratum?

15)

A) A B) B C) C D) D

16) Logically, which of these should cast the most doubt on the relationships depicted by anevolutionary tree?

16)

A) The skeletal remains of the organisms depicted by the tree were incomplete (in other words,some bones were missing).

B) None of the organisms depicted by the tree ate the same foods.C) Relationships between DNA sequences among the species did not match relationships

between skeletal patterns.D) Some of the organisms depicted by the tree had lived in different habitats.E) Transitional fossils had not been found.

17) Which of the following is a true statement concerning genetic variation? 17)A) It tends to be reduced by the processes involved when diploid organisms produce gametes.B) It arises in response to changes in the environment.C) A population that has a higher average heterozygosity has less genetic variation than one

with a lower average heterozygosity.D) It is created by the direct action of natural selection.E) It must be present in a population before natural selection can act upon the population.

3

18) If the original finches that had been blown over to the Galápagos from South America had alreadybeen genetically different from the parental population of South American finches, even beforeadapting to the Galápagos, this would have been an example of

18)

A) genetic drift.B) bottleneck effect.C) founder effect.D) all three of these.E) both the first and third of these.

19) Rank the following one-base point mutations (from most likely to least likely) with respect to theirlikelihood of affecting the structure of the corresponding polypeptide:1. insertion mutation deep within an intron2. substitution mutation at the third position of an exonic codon3. substitution mutation at the second position of an exonic codon4. deletion mutation within the first exon of the gene

19)

A) 2, 1, 4, 3 B) 2, 3, 1, 4 C) 4, 3, 2, 1 D) 1, 2, 3, 4 E) 3, 1, 4, 2

20) Although each of the following has a better chance of influencing gene frequencies in smallpopulations than in large populations, which one most consistently requires a small population as aprecondition for its occurrence?

20)

A) genetic driftB) mutationC) nonrandom matingD) natural selectionE) gene flow

21) Which statement about the beak size of finches on the island of Daphne Major during prolongeddrought is true?

21)

A) Each bird that survived the drought produced only offspring with deeper, stronger beaksthan seen in the previous generation.

B) Each bird's survival was strongly influenced by the depth and strength of its beak as thedrought persisted.

C) The frequency of the strong-beak alleles increased in each bird as the drought persisted.D) Each bird evolved a deeper, stronger beak as the drought persisted.

22) Natural selection changes allele frequencies because some ________ survive and reproduce moresuccessfully than others.

22)

A) lociB) allelesC) gene poolsD) speciesE) individuals

23) What is true of natural selection? 23)A) Natural selection is a random process.B) The only way to eliminate harmful mutations is through natural selection.C) Natural selection creates beneficial mutations.D) Mutations occur when directed by the good of the species; natural selection edits out harmful

mutations and causes populations to adapt to the beneficial mutations.E) Mutations occur at random; natural selection can preserve and distribute beneficial

mutations.

4

24) The volcano is currently dormant, but in a hypothetical future scenario, satellite cones at the base ofMt. Kilimanjaro spew sulfurous gases and lava, destroying all life located between the base and6,000 feet above sea level. As a result of this catastrophe, how should the frequency of thesickle-cell allele change in the remnant human population that survives above 6,000 feet, andwhich phenomenon accounts for this change in allele frequency?

24)

A) decreases; disruptive selectionB) increases; nonrandom matingC) increases; genetic driftD) decreases; bottleneck effectE) decreases; gene flow

25) Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer, or more,than this have reduced fitness. Which of the following terms best describes this situation?

25)

A) stabilizing selectionB) disruptive selectionC) sexual selectionD) artificial selectionE) directional selection

26) Adult male humans generally have deeper voices than do adult female humans, which is the directresult of higher levels of testosterone causing growth of the larynx. If one excludes the involvementof gender in the situation, then the pattern that is apparent in the fossil record is most similar to onethat should be expected from

26)

A) directional selection.B) pansexual selection.C) disruptive selection.D) stabilizing selection.E) asexual selection.

27) Most invertebrates have a cluster of ten similar Hox genes, all located on the same chromosome.Most vertebrates have four such clusters of Hox genes, located on four nonhomologouschromosomes. The process that could have potentially contributed to the cluster's presence on morethan one chromosome was ________.

27)

A) transcriptionB) translationC) gene duplicationD) nondisjunctionE) binary fission

28) If, on average, 46% of the loci in a species' gene pool are heterozygous, then the averagehomozygosity of the species should be

28)

A) 46%. B) 23%.C) 54%. D) There is not enough information to say.

29) A trend toward the decrease in the size of plants on the slopes of mountains as altitudes increase isan example of

29)

A) a bottleneck.B) a cline.C) relative fitness.D) geographic variation.E) genetic drift.

5

Use the following information to answer the following questions.

In those parts of equatorial Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the hemoglobin alleles in the human gene pool.

30) The sickle-cell allele is pleiotropic (i.e., it affects more than one phenotypic trait). Specifically, thisallele affects oxygen delivery to tissues and affects one's susceptibility to malaria. Under conditionsof low atmospheric oxygen availability, individuals heterozygous for this allele can experiencelife-threatening sickle-cell "crises." Such individuals remain less susceptible to malaria. Thus,pleiotropic genes/alleles such as this can help explain why

30)

A) adaptations are often compromises.B) evolution is limited by historical constraints.C) chance events can affect the evolutionary history of populations.D) new advantageous alleles do not arise on demand.

In a very large population, a quantitative trait has the following distribution pattern:

31) What is true of the trait whose frequency distribution in a large population appears in the previousfigure? It has probably undergone

31)

A) disruptive selection. B) normal selection.C) stabilizing selection. D) directional selection.

32) In the formula for determining a population’s genotype frequencies, the pq in the term 2pq isnecessary because

32)

A) the population is doubling in number.B) heterozygotes have two alleles.C) the population is diploid.D) heterozygotes can come about in two ways.

33) Which of the following statements best summarizes evolution as it is viewed today? 33)A) It represents the result of selection for acquired characteristics.B) It is the descent of humans from the present-day great apes.C) It is synonymous with the process of gene flow.D) It is the differential survival and reproduction of the most-fit phenotypes.

6

34) The difference between geographic isolation and habitat differentiation is the 34)A) speed (tempo) at which two populations undergo speciation.B) identity of the phylogenetic kingdom or domain in which these phenomena occur.C) amount of genetic variation that occurs among two gene pools as speciation occurs.D) relative locations of two populations as speciation occurs.E) the ploidy of the two populations as speciation occurs.

35) Two species of frogs belonging to the same genus occasionally mate, but the offspring fail todevelop and hatch. What is the mechanism for keeping the two frog species separate?

35)

A) the prezygotic barrier called hybrid sterilityB) the postzygotic barrier called hybrid inviabilityC) gametic isolationD) the postzygotic barrier called hybrid breakdown

The next few questions refer to the following evolutionary tree, whose horizontal axis represents time (present time is on thefar right) and whose vertical axis represents morphological change.

36) Which of these five species is the extant (i.e., not extinct) species that is most closely related tospecies X, and why is this so?

36)

A) Y; arose in the same fashion (i.e., at the same tempo) as XB) W; shared a common ancestor with X most recentlyC) Z; shared a common ancestor with X most recently, and arose in the same fashion as XD) V; shared a common ancestor with X most recentlyE) This tree does not provide enough information to answer this question.

37) According to the concept of punctuated equilibrium, the "sudden" appearance of a new species inthe fossil record means that

37)

A) speciation occurred rapidly in geologic time.B) the species is now extinct.C) speciation occurred in one generation.D) the species will consequently have a relatively short existence, compared with other species.E) speciation occurred instantaneously.

7

38) Which of the following factors would not contribute to allopatric speciation? 38)A) Different mutations begin to distinguish the gene pools of the separated populations.B) The isolated population is exposed to different selection pressures than the ancestral

population.C) The separated population is small, and genetic drift occurs.D) A population becomes geographically isolated from the parent population.E) Gene flow between the two populations is extensive.

39) Plant species A has a diploid number of 12. Plant species B has a diploid number of 16. A newspecies, C, arises as an allopolyploid from A and B. The diploid number for species C wouldprobably be

39)

A) 14. B) 56. C) 28. D) 12. E) 16.

40) In order for speciation to occur, what must be true? 40)A) Changes to centromere location or chromosome size must occur within the gene pool.B) At least one gene, affecting at least one phenotypic trait, must change.C) Large numbers of genes that affect a single phenotypic trait must change.D) Large numbers of genes that affect numerous phenotypic traits must change.E) The number of chromosomes in the gene pool must change.

41) The most likely explanation for the high rate of sympatric speciation that apparently existed amongthe cichlids of Lake Victoria in the past is

41)

A) habitat differentiation.B) polyploidy.C) sexual selection.D) introduction of a new predator.E) pollution.

42) What is true of the flightless cormorants of the Galápagos Islands? 42)A) Flightless cormorants on one island have restricted gene flow with those on other islands,

which could someday lead to a macroevolutionary event.B) They are close relatives of flightless cormorants from the Americas.C) Their DNA has low levels of sequence homology with the DNA of flying American

cormorants.D) If they are still able to breed successfully with flying cormorants, it would probably be with

North American cormorants, rather than with South American cormorants.E) They are descendants of the same common ancestor that gave rise to the unique finches of

these islands.

43) Speciation 43)A) can involve changes to a single gene.B) occurs only by the accumulation of genetic change over vast expanses of time.C) occurs at such a slow pace that no one has ever observed the emergence of new species.D) must begin with the geographic isolation of a small, frontier population.E) and microevolution are synonymous.

8

44) Males of different species of the fruit fly Drosophila that live in the same parts of the HawaiianIslands have different elaborate courtship rituals. These rituals involve fighting other males andmaking stylized movements that attract females. What type of reproductive isolation does thisrepresent?

44)

A) behavioral isolationB) habitat isolationC) postzygotic barriersD) temporal isolationE) gametic isolation

45) Which of the following statements about species, as defined by the biological species concept, is(are) correct?I. Biological species are defined by reproductive isolation.II. Biological species are the model used for grouping extinct forms of life.III. The biological species is the largest unit of population in which successful interbreeding ispossible.

45)

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

46) The snowball Earth hypothesis provides a possible explanation for the 46)A) oxygenation of Earth's seas and atmosphere.B) colonization of land by plants and fungi.C) origin of oxygen-releasing photosynthesis.D) diversification of animals during the late Proterozoic era.E) existence of prokaryotes around hydrothermal vents on the ocean floor.

47) Recent evidence indicates that the first major diversification of multicellular eukaryotes may havecoincided in time with the

47)

A) melting that ended the "snowball Earth" period.B) massive eruptions of deep-sea vents.C) origin of multicellular organisms.D) switch to an oxidizing atmosphere.E) origin of prokaryotes.

48) Approximately how far back in time does the fossil record extend? 48)A) 5.0 billion years B) 3.5 million yearsC) 5.0 million years D) 3.5 billion years

49) The loss of ventral spines by modern freshwater sticklebacks is due to natural selection operatingon the phenotypic effects of Pitx1 gene

49)

A) silencing (loss of expression). B) elimination (loss).C) duplication (gain in number). D) mutation (change).

50) A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swimbladder from lungs of an ancestral fish is an example of

50)

A) paedomorphosis.B) exaptation.C) changes in Hox gene expression.D) adaptive radiation.E) an evolutionary trend.

9

51) The major evolutionary episode corresponding most closely in time with the formation of Pangaeawas the

51)

A) Cretaceous extinctions. B) Cambrian explosion.C) Permian extinctions. D) Pleistocene ice ages.

52) If a fossil is encased in a stratum of sedimentary rock without any strata of igneous rock (forexample, lava, volcanic ash) nearby, then it should be

52)

A) easy to determine, as long as there is enough metamorphic rock nearby.B) easy to determine the absolute age of the fossil, because the igneous rocks will not have

physically obstructed the deposition of sediment of a single age next to the fossil.C) difficult to determine the absolute age of the fossil, because radiometric dating of sedimentary

rock is less accurate than that of igneous rock.D) difficult to determine the absolute age of the fossil, because the "marker fossils" common to

igneous rock will be absent.E) easy to determine the absolute age of the fossil, because the radioisotopes in the sediments

will not have been "reset" by the heat of the igneous rocks.

53) Which of the following characteristics should have been possessed by the first animals to colonizeland?1. were probably herbivores (ate photosynthesizers)2. had four appendages3. had the ability to resist dehydration4. had lobe-finned fishes as ancestors5. were invertebrates

53)

A) 1, 2, 3, and 4B) 3 and 5C) 2, 3, and 4D) 3 onlyE) 1, 3, and 5

54) What is thought to be the correct sequence of these events, from earliest to most recent, in theevolution of life on Earth?1. origin of mitochondria2. origin of multicellular eukaryotes3. origin of chloroplasts4. origin of cyanobacteria5. origin of fungal-plant symbioses

54)

A) 4, 1, 2, 3, 5 B) 4, 1, 3, 2, 5 C) 4, 3, 1, 5, 2 D) 4, 3, 2, 1, 5 E) 4, 3, 1, 2, 5

55) Adaptive radiations can be a direct consequence of four of the following five factors. Select theexception.

55)

A) vacant ecological nichesB) colonization of an isolated region that contains suitable habitat and few competitor speciesC) genetic driftD) an adaptive radiation in a group of organisms (such as plants) that another group uses as

foodE) evolutionary innovation

10

The following questions refer to the description below.

All animals with eyes or eyespots that have been studied so far share a gene in common. When mutated, the gene Pax-6causes lack of eyes in fruit flies, tiny eyes in mice, and missing irises (and other eye parts) in humans. The sequence of Pax-6in humans and mice is identical. There are so few sequence differences with fruit fly Pax-6 that the human/mouse versioncan cause eye formation in eyeless fruit flies, even though vertebrates and invertebrates last shared a common ancestor morethan 500 million years ago.

56) Pax-6 usually causes the production of a type of light-receptor pigment. In vertebrate eyes, though,a different gene (the rh gene family) is responsible for the light-receptor pigments of the retina. Therh gene, like Pax-6, is ancient. In the marine ragworm, for example, the rh gene causes productionof c-opsin, which helps regulate the worm's biological clock. Which of these most likely accountsfor vertebrate vision?

56)

A) The Pax-6 gene mutated to become the rh gene among early mammals.B) Pax-6 was lost from the mammalian genome, and replaced by the rh gene much later.C) During vertebrate evolution, the rh gene for biological clock opsin was co-opted as a gene for

visual receptor pigments.D) In animals more ancient than ragworms, the rh gene(s) coded for visual receptor pigments; in

lineages more recent than ragworms, rh has flip-flopped several times between producingbiological clock opsins and visual receptor pigments.

57) Which of these observations gives the most support to the endosymbiotic theory for the origin ofeukaryotic cells?

57)

A) the size disparity between most prokaryotic cells and most eukaryotic cellsB) the observation that some eukaryotic cells lack mitochondriaC) the existence of structural and molecular differences between the plasma membranes of

prokaryotes and the internal membranes of mitochondria and chloroplastsD) the similarity in size between the cytosolic ribosomes of prokaryotes and the ribosomes

within mitochondria and chloroplasts

58) The oxygen revolution changed Earth's environment dramatically. Which of the following tookadvantage of the presence of free oxygen in the oceans and atmosphere?

58)

A) the persistence of some animal groups in anaerobic habitatsB) the evolution of photosynthetic pigments that protected early algae from the corrosive effects

of oxygenC) the evolution of cellular respiration, which used oxygen to help harvest energy from organic

moleculesD) the evolution of multicellular eukaryotic colonies from communities of prokaryotesE) the evolution of chloroplasts after early protists incorporated photosynthetic cyanobacteria

59) Which of the following statements provides the strongest evidence that prokaryotes evolved beforeeukaryotes?

59)

A) Liposomes closely resemble prokaryotic cells.B) Prokaryotic cells lack nuclei.C) The oldest fossilized cells resemble prokaryotes.D) The meteorites that have struck Earth contain fossils only of prokaryotes.E) Laboratory experiments have produced liposomes abiotically.

11

60) What is true of the fossil record of mammalian origins? 60)A) It shows that mammals and birds evolved from the same kind of dinosaur.B) It indicates that mammals and dinosaurs did not overlap in geologic time.C) It is a good example of punctuated equilibrium.D) It includes transitional forms with progressively specialized teeth.E) It includes a series that shows the gradual change of scales into fur.

61) Which of the following is true of all horizontally oriented phylogenetic trees, where time advancesto the right?

61)

A) The more branch points there are, the fewer taxa are likely to be represented.B) The common ancestor represented by the rightmost branch point existed more recently in

time than the common ancestors represented at branch points located to the left.C) Organisms represented at the base of such trees are descendants of those represented at

higher levels.D) Each branch point represents a point in absolute time.E) The fewer branch points that occur between two taxa, the more divergent their DNA

sequences should be.

62) Which statement represents the best explanation for the observation that the nuclear DNA ofwolves and domestic dogs has a very high degree of sequence homology?

62)

A) Dogs and wolves have very similar morphologies.B) Dogs and wolves shared a common ancestor very recently.C) Dogs and wolves belong to the same order.D) Dogs and wolves are both members of the order Carnivora.

63) If, someday, an archaean cell is discovered whose rRNA sequence is more similar to that of humansthan the sequence of mouse rRNA is to that of humans, the best explanation for this apparentdiscrepancy would be

63)

A) homoplasy.B) common ancestry.C) coevolution of humans and that archaean.D) retro-evolution by humans.E) homology.

64) Paralogous genes that have lost the function of coding for any functional gene product are knownas "pseudogenes." Which of these is a valid prediction regarding the fate of pseudogenes overevolutionary time?

64)

A) They will ultimately regain their original function.B) They will be highly conserved.C) They will have relatively high mutation rates.D) They will be preserved by natural selection.E) They will be transformed into orthologous genes.

65) Which kingdom has been replaced with two domains? 65)A) Protista B) Plantae C) Animalia D) Monera E) Fungi

66) Which of the following is (are) problematic when the goal is to construct phylogenies thataccurately reflect evolutionary history?

66)

A) monophyletic taxa B) polyphyletic taxaC) paraphyletic taxa D) Two of the responses are correct.

12

67) A phylogenetic tree constructed using sequence differences in mitochondrial DNA would be mostvalid for discerning the evolutionary relatedness of

67)

A) chimpanzees and humans.B) archaeans and bacteria.C) mosses and ferns.D) fungi and animals.E) sharks and dolphins.

68) What kind of evidence has recently made it necessary to assign the prokaryotes to either of twodifferent domains, rather than assigning all prokaryotes to the same kingdom?

68)

A) molecularB) anatomicalC) ecologicalD) behavioralE) nutritional

69) Which of the following items does not necessarily exist in a simple linear relationship with thenumber of gene-duplication events when placed as the label on the vertical axis of the followinggraph?

69)

A) number of genesB) number of DNA base pairsC) genome sizeD) phenotypic complexityE) mass (in picograms) of DNA

70) Which eukaryotic kingdom is polyphyletic, and therefore unacceptable, based on cladistics? 70)A) Fungi B) Protista C) Monera D) Animalia E) Plantae

71) Neutral theory proposes that 71)A) molecular clocks are more reliable when the surrounding pH is close to 7.0.B) most mutations of highly conserved DNA sequences should have no functional effect.C) a significant proportion of mutations are not acted upon by natural selection.D) DNA is less susceptible to mutation when it codes for amino acid sequences whose side

groups (or R groups) have a neutral pH.E) DNA is less susceptible to mutation when it codes for amino acid sequences whose side

groups (or R groups) have a neutral electrical charge.

13

72) Based on this tree, which statement is not correct? 72)

A) The salamander lineage is a basal taxon.B) Salamanders are as closely related to goats as to humans.C) Salamanders are a sister group to the group containing lizards, goats, and humans.D) Lizards are more closely related to salamanders than to humans.

73) In a comparison of birds and mammals, having four limbs is 73)A) a shared ancestral character.B) a character useful for distinguishing birds from mammals.C) an example of analogy rather than homology.D) a shared derived character.E) a character useful for sorting bird species.

Figure 26.5. Humans, chimpanzees, gorillas, and orangutans are members of a clade called the great apes, which shared acommon ancestor about 18 million years ago (Figure 26.4). Gibbons and siamangs comprise a clade called the lesser apes.Tree-branch lengths indicate elapsed time.

74) From Figure 26.5, to which of the extant apes are orangutans most closely related? 74)A) gorillasB) chimpsC) chimps, gorillas, and humansD) gibbons and siamangsE) Dryopithecus and Ouranopithecus

14

75) Which individual would make the worst systematist? One who is uncomfortable with the 75)A) Linnaean system of classification. B) notion of hypothetical phylogenies.C) notion of permanent polytomies. D) PhyloCode method of classification.

76) Mitochondria are thought to be the descendants of certain alpha proteobacteria. They are, however,no longer able to lead independent lives because most genes originally present on theirchromosome have moved to the nuclear genome. Which phenomenon accounts for the movementof these genes?

76)

A) conjugationB) plasmolysisC) horizontal gene transferD) endocytosisE) translation

77) Though plants, fungi, and prokaryotes all have cell walls, we place them in different taxa. Which ofthese observations comes closest to explaining the basis for placing these organisms in differenttaxa, well before relevant data from molecular systematics became available?

77)

A) Some have cell walls only for support.B) Some closely resemble animals, which lack cell walls.C) Some have cell walls only to control osmotic balance.D) Some have cell walls only for protection from herbivores.E) Their cell walls are composed of very different biochemicals.

78) In general, what is the primary ecological role of prokaryotes? 78)A) parasitizing eukaryotes, thus causing diseasesB) metabolizing materials in extreme environmentsC) adding methane to the atmosphereD) breaking down organic matterE) serving as primary producers in terrestrial environments

The following table depicts characteristics of five prokaryotic species (A—E). Use the information in the table to answer thefollowing questions.

Trait Species A Species B Species C Species D Species EPlasmid R None R F NoneGram StainingResults

Variable Variable Negative Negative Negative

NutritionalMode

Chemohetero-

trophChemoauto-

trophChemohetero-

trophChemohetero-

trophPhotoautotroph

SpecializedMetabolicPathways

Aerobicmethanotroph(obtains carbonand energy frommethane)

Anaerobicmethanogen

Anaerobicbutanolicfermentation

Anaerobic lacticacidfermentation

Anaerobicnitrogen fixationand aerobicphotosystemsI and II

Other Features Fimbriae Internalmembranes

Flagellum Pili Thylakoids

79) Which species is probably an important contributor to the base of aquatic food chains as a primaryproducer?

79)

A) species A B) species B C) species C D) species D E) species E

15

Use the information in the following paragraph to answer the next few questions.

A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. Itadheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecalmatter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with waterand boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively littlepeptidoglycan.

80) This bacterium's ability to survive in a human who is taking penicillin pills may be due to thepresence of1. penicillin-resistance genes2. a secretory system that removes penicillin from the cell3. a gram-positive cell wall4. a gram-negative cell wall5. an endospore

80)

A) 1 or 5 B) 2, 4, or 5 C) 4 or 5 D) 2, 3, or 5 E) 2 or 3

81) If archaeans are more closely related to eukaryotes than to bacteria, then which of the following is areasonable prediction?

81)

A) Archaean chromosomes should have no protein bonded to them.B) Archaean DNA should have no introns.C) Archaeans should lack cell walls.D) Archaean DNA should be single-stranded.E) Archaean ribosomes should be larger than typical prokaryotic ribosomes.

The following table depicts characteristics of five prokaryotic species (A—E). Use the information in the table to answer thefollowing questions.

Trait Species A Species B Species C Species D Species EPlasmid R None R F NoneGram StainingResults

Variable Variable Negative Negative Negative

NutritionalMode

Chemohetero-

trophChemoauto-

trophChemohetero-

trophChemohetero-

trophPhotoautotroph

SpecializedMetabolicPathways

Aerobicmethanotroph(obtains carbonand energy frommethane)

Anaerobicmethanogen

Anaerobicbutanolicfermentation

Anaerobic lacticacidfermentation

Anaerobicnitrogen fixationand aerobicphotosystemsI and II

Other Features Fimbriae Internalmembranes

Flagellum Pili Thylakoids

82) Which two species should have much more phospholipid, in the form of bilayers, in theircytoplasms than most other bacteria?

82)

A) species A and BB) species A and CC) species B and ED) species C and DE) species C and E

16

83) Which species is most likely to be found both in sewage treatment plants and in the guts of cattle? 83)A) species A B) species B C) species C D) species D E) species E

84) Plantlike photosynthesis that releases O2 occurs in 84)A) actinomycetes.B) archaea.C) chemoautotrophic bacteria.D) chlamydias.E) cyanobacteria.

85) The thermoacidophile, Sulfolobus acidocaldarius, lacks peptidoglycan, but still possesses a cell wall.What is likely to be true of this species?1. It is a bacterium.2. It is an archaean.3. The optimal pH of its enzymes will lie above pH 7.4. The optimal pH of its enzymes will lie below pH 7.5. It could inhabit certain hydrothermal springs.6. It could inhabit alkaline hot springs.

85)

A) 1, 3, and 6 B) 1, 4, and 5 C) 1, 3, and 5 D) 2, 4, and 5 E) 2, 4, and 6

86) Broad-spectrum antibiotics inhibit the growth of most intestinal bacteria. Consequently, assumingthat nothing is done to counter the reduction of intestinal bacteria, a hospital patient who isreceiving broad-spectrum antibiotics is most likely to become

86)

A) unable to synthesize peptidoglycan.B) unable to fix nitrogen.C) unable to fix carbon dioxide.D) antibiotic resistant.E) deficient in certain vitamins and nutrients.

87) Which of the following obtain energy by oxidizing inorganic substances energy that is used, inpart, to fix CO2?

87)

A) chemoheterotrophs that perform decompositionB) photoheterotrophsC) parasitic chemoheterotrophsD) photoautotrophsE) chemoautotrophs

88) Which of the following involves metabolic cooperation among prokaryotic cells? 88)A) binary fissionB) endospore formationC) biofilmsD) photoautotrophyE) endotoxin release

17

89) The predatory bacterium, Bdellovibrio bacteriophorus, drills into a prey bacterium and, once inside,digests it. In an attack upon a gram-negative bacterium that has a slimy cell covering, what is thecorrect sequence of structures penetrated by B. bacteriophorus on its way to the prey's cytoplasm?1. membrane composed mostly of lipopolysaccharide2. membrane composed mostly of phospholipids3. peptidoglycan4. capsule

89)

A) 1, 3, 4, 2 B) 1, 4, 3, 2 C) 4, 1, 3, 2 D) 4, 3, 1, 2 E) 2, 4, 3, 1

90) Which statement about the domain Archaea is true? 90)A) The genomes of archaeans are unique, containing no genes that originated within bacteria.B) Genetic prospecting has recently revealed the existence of many previously unknown

archaean species.C) No archaeans can reduce CO2 to methane.D) No archaeans can inhabit solutions that are nearly 30% salt.E) No archaeans are adapted to waters with temperatures above the boiling point.

91) Bacteria perform each of the following ecological roles. Which role typically does not involve asymbiosis?

91)

A) pathogenB) skin commensalistC) aggregates with methane-consuming archaeaD) decomposerE) gut mutualist

18

The following questions refer to Figure 27.1.

In this eight-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditionsfor 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples wereremoved from the populations, and their fitness in low-glucose conditions was tested against that of members sampled fromthe ancestral (common ancestor) E. coli population.

Figure 27.1

92) Which of the following, if it occurs in the absence of any other type of adaptation listed here, is leastreasonable in terms of promoting bacterial survival over evolutionary time in a low-glucoseenvironment?

92)

A) increased efficiency at transporting glucose into the cell from the environmentB) increased reliance on glycolytic enzymesC) increased ability to synthesize glucose from amino acid precursorsD) increased sensitivity to, and ability to move toward, whatever glucose is present in its habitatE) increased ability to survive on simple sugars, other than glucose

93) Genetic variation in bacterial populations cannot result from 93)A) conjugationB) meiosis.C) mutation.D) transformationE) transduction.

19