Archive for December 2016

Renoir's Luncheon of the Boating Party reflects a modern sensibility due mostly to its

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Renoir's Luncheon of the Boating Party reflects a modern sensibility due mostly to its






A) an assembly of people from varied backgrounds or social classes
B) a still life symbolizing the transient, fleeting qualities of life
C) an intimate, voyeuristic scene where the viewer is made to feel uncomfortably distant
D) an unsettling, pyschological distance portrayed between the sexes






Answer: A

Both Judith Leyster and Frans Hals were known for their

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Both Judith Leyster and Frans Hals were known for their






A) portraits of lower and middle class subjects
B) landscapes with moral overtones
C) genre scenes lit with daylight passing through a window
D) prints of religious narratives and parables







Answer: A

In Rococo paintings, figures are most likely to be depicted

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In Rococo paintings, figures are most likely to be depicted 





A) as actively engaged or religiously motivated
B) as examples of moral virtue or patriotism
C) in classical dress or as allegorical figures
D) at leisure in luxurious settings or in repose









Answer: D

Turner's Fighting Temeraire refers to which of the following?

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Turner's Fighting Temeraire refers to which of the following?





A) the cruel atrocities committed by men in the slave trade
B) the heroic grandeur of Britain's past in the Battle of Trafalgar
C) the hubris associated with Hannibal's passage through the Alps
D) the dramatic events that led to Britain's role in the Seven Years War






Answer: B

Why did Diego Velazquez paint his Las Meninas?

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Why did Diego Velazquez paint his Las Meninas?





A) as a diplomatic gift to a foreign ruler
B) so that the artist could join a confraternity
C) to be placed within a family chapel
D) to adorn the king's private apartments








Answer: D

One explanation for the evolution of insect wings suggests that wings began as lateral extensions of the body that were used as heat dissipaters for thermoregulation. When they had become sufficiently large, these extensions became useful for gliding through the air, and selection later refined them as flight-producing wings. If this hypothesis is correct, modern insect wings could best be described as

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One explanation for the evolution of insect wings suggests that wings began as lateral extensions of the body that were used as heat dissipaters for thermoregulation. When they had become sufficiently large, these extensions became useful for gliding through the air, and selection later refined them as flight-producing wings. If this hypothesis is correct, modern insect wings could best be described as 





A) adaptations.
B) mutations.
C) exaptations.
D) isolating mechanisms.
E) examples of natural selection's predictive ability.







Answer: C

The existence of the phenomenon of exaptation is most closely associated with which of the following observations that natural selection cannot fashion perfect organisms?

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The existence of the phenomenon of exaptation is most closely associated with which of the following observations that natural selection cannot fashion perfect organisms? 





A) Natural selection and sexual selection can work at cross-purposes to each other.
B) Evolution is limited by historical constraints.
C) Adaptations are often compromises.
D) Chance events affect the evolutionary history of populations in environments that can change unpredictably.





Answer: B

How many of the following statements concerning the loss of hind limbs during whale evolution are true? 1. It is well documented by a series of transitional fossils. 2. It explains why modern whales have vestigial pelvic girdles. 3. It involved changes in the sequence or expression of Hox genes. 4. It is an example of macroevolution. 5. It, and the loss of limbs by snakes, are an example of similar adaptations to a similar environment.

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How many of the following statements concerning the loss of hind limbs during whale evolution are true?
1. It is well documented by a series of transitional fossils.
2. It explains why modern whales have vestigial pelvic girdles.
3. It involved changes in the sequence or expression of Hox genes.
4. It is an example of macroevolution.
5. It, and the loss of limbs by snakes, are an example of similar adaptations to a similar environment. 






A) Only one statement is true.
B) Two statements are true.
C) Three statements are true.
D) Four statements are true.
E) All five statements are true.







Answer: D

Larval flies (maggots) express the Ubx gene in all of their segments, and thereby lack appendages. If this same gene continued to be expressed throughout subsequent developmental stages, except in the head region, and if the result was a fit, sexually mature organism that still strongly resembled a maggot, this would be an example of

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Larval flies (maggots) express the Ubx gene in all of their segments, and thereby lack appendages. If this same gene continued to be expressed throughout subsequent developmental stages, except in the head region, and if the result was a fit, sexually mature organism that still strongly resembled a maggot, this would be an example of 








A) paedomorphosis.
B) homochrony.
C) heterochrony.
D) Two of the responses above are correct.







Answer: D

Bagworm moth caterpillars feed on evergreens and carry a silken case or bag around with them in which they eventually pupate. Adult female bagworm moths are larval in appearance; they lack the wings and other structures of the adult male and instead retain the appearance of a caterpillar even though they are sexually mature and can lay eggs within the bag. This is a good example of

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Bagworm moth caterpillars feed on evergreens and carry a silken case or bag around with them in which they eventually pupate. Adult female bagworm moths are larval in appearance; they lack the wings and other structures of the adult male and instead retain the appearance of a caterpillar even though they are sexually mature and can lay eggs within the bag. This is a good example of 






A) allometric growth.
B) paedomorphosis.
C) sympatric speciation.
D) adaptive radiation.
E) changes in homeotic genes.





Answer: B

An organism has a relatively large number of Hox genes in its genome. Which of the following is true of this organism?

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An organism has a relatively large number of Hox genes in its genome. Which of the following is true of this organism? 





A) These genes are fundamental, and are expressed in all cells of the organism.
B) The organism must have multiple paired appendages along the length of its body.
C) The organism has the genetic potential to have a relatively complex anatomy.
D) Most of its Hox genes owe their existence to gene fusion events.
E) Its Hox genes cooperate to bring about sexual maturity at the proper stage of development.







Answer: C

On the basis of their morphologies, how might Linnaeus have classified the Hawaiian silverswords?

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On the basis of their morphologies, how might Linnaeus have classified the Hawaiian silverswords?





A) He would have placed them all in the same species.
B) He would have classified them the same way that modern botanists do.
C) He would have placed them in more species than modern botanists do.
D) He would have used evolutionary relatedness as the primary criterion for their classification.








Answer: C

If two continents converge and are united, then the collision should cause

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If two continents converge and are united, then the collision should cause 






A) a net loss of intertidal zone and coastal habitat.
B) the extinction of any species adapted to intertidal and coastal habitats.
C) an overall decrease in the surface area located in the continental interior.
D) a decrease in climatic extremes in the interior of the new supercontinent.
E) the maintenance of the previously existing ocean currents and wind patterns.






Answer: A

The first terrestrial organisms probably were considered which of the following? 1. burrowers 2. photosynthetic 3. multicellular 4. prokaryotes 5. eukaryotes 6. plants and their associated fungi

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The first terrestrial organisms probably were considered which of the following?
1. burrowers
2. photosynthetic
3. multicellular
4. prokaryotes
5. eukaryotes
6. plants and their associated fungi 





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





Answer: A

Which of the following characteristics should have been possessed by the first animals to colonize land? 1. were probably herbivores (ate photosynthesizers) 2. had four appendages 3. had the ability to resist dehydration 4. had lobe-finned fishes as ancestors 5. were invertebrates

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Which of the following characteristics should have been possessed by the first animals to colonize land?
1. were probably herbivores (ate photosynthesizers)
2. had four appendages
3. had the ability to resist dehydration
4. had lobe-finned fishes as ancestors
5. were invertebrates 







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




Answer: C

The snowball Earth hypothesis provides a possible explanation for the

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The snowball Earth hypothesis provides a possible explanation for the 





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






Answer: A

Which of these observations gives the most support to the endosymbiotic theory for the origin of eukaryotic cells?

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Which of these observations gives the most support to the endosymbiotic theory for the origin of eukaryotic cells? 






A) the existence of structural and molecular differences between the plasma membranes of prokaryotes and the internal membranes of mitochondria and chloroplasts
B) the similarity in size between the cytosolic ribosomes of prokaryotes and the ribosomes within mitochondria and chloroplasts
C) the size disparity between most prokaryotic cells and most eukaryotic cells
D) the observation that some eukaryotic cells lack mitochondria






Answer: B

Recent evidence indicates that the first major diversification of multicellular eukaryotes may have coincided in time with the

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Recent evidence indicates that the first major diversification of multicellular eukaryotes may have coincided in time with the 





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






Answer: C

If it were possible to conduct sophisticated microscopic and chemical analyses of microfossils found in 3.2-billion-year-old stromatolites, then one should be surprised to observe evidence of which of the following within such microfossils? I. double-stranded DNA II. a nuclear envelope III. a nucleoid IV. a nucleolus V. ribosomes

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If it were possible to conduct sophisticated microscopic and chemical analyses of microfossils found in 3.2-billion-year-old stromatolites, then one should be surprised to observe evidence of which of the following within such microfossils?
I. double-stranded DNA
II. a nuclear envelope
III. a nucleoid
IV. a nucleolus
V. ribosomes 





A) II only
B) III only
C) II and IV
D) II, III, and IV
E) all five of these






Answer: C

What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth? 1. origin of mitochondria 2. origin of multicellular eukaryotes 3. origin of chloroplasts 4. origin of cyanobacteria 5. origin of fungal-plant symbioses

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What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth?
1. origin of mitochondria
2. origin of multicellular eukaryotes
3. origin of chloroplasts
4. origin of cyanobacteria
5. origin of fungal-plant symbioses 






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





Answer: C

What is true of the Cambrian explosion?

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What is true of the Cambrian explosion? 





A) There are no fossils in geological strata that are older than the Cambrian explosion.
B) Only the fossils of microorganisms are found in geological strata older than the Cambrian explosion.
C) The Cambrian explosion is evidence for the instantaneous creation of life on Earth.
D) The Cambrian explosion marks the appearance of filter-feeding animals in the fossil record.
E) Recent evidence supports the contention that the Cambrian explosion may not have been as "explosive" as was once thought.






Answer: E

Which of the following statements provides the strongest evidence that prokaryotes evolved before eukaryotes?

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Which of the following statements provides the strongest evidence that prokaryotes evolved before eukaryotes? 






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







Answer: E

An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to

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An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to 






A) generate intense lightning storms.
B) change the atmosphere from oxidizing to reducing.
C) make it easier to maintain reduced molecules.
D) cause iron in ocean water and terrestrial rocks to rust (oxidize).
E) prevent the formation of an ozone layer.








Answer: D

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

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





A) 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.
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) easy to determine, as long as there is enough metamorphic rock nearby.
D) difficult to determine the absolute age of the fossil, because the "marker fossils" common to igneous rock will be absent.
E) difficult to determine the absolute age of the fossil, because radiometric dating of sedimentary rock is less accurate than that of igneous rock.








Answer: E

What is true of the fossil record of mammalian origins?

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What is true of the fossil record of mammalian origins? 






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







Answer: C

If natural selection in a particular environment favored genetic systems that permitted the production of daughter "cells" that were genetically dissimilar from the mother "cells," then one should expect selection for which of the following? I. polynucleotide polymerase with low mismatch error rates II. polynucleotide polymerases without proofreading capability III. batteries of efficient polynucleotide repair enzymes IV. polynucleotide polymerases with proofreading capability V. polynucleotide polymerases with high mismatch error rates

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If natural selection in a particular environment favored genetic systems that permitted the production of daughter "cells" that were genetically dissimilar from the mother "cells," then one should expect selection for which of the following?
I. polynucleotide polymerase with low mismatch error rates
II. polynucleotide polymerases without proofreading capability
III. batteries of efficient polynucleotide repair enzymes
IV. polynucleotide polymerases with proofreading capability
V. polynucleotide polymerases with high mismatch error rates 






A) I only
B) I and IV
C) I, III, and IV
D) II and V
E) II, III and V







Answer: D

Several scientific laboratories across the globe are involved in research concerning the origin of life on Earth. Which of these questions is currently the most problematic and would have the greatest impact on our understanding if we were able to answer it?

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Several scientific laboratories across the globe are involved in research concerning the origin of life on Earth. Which of these questions is currently the most problematic and would have the greatest impact on our understanding if we were able to answer it? 





A) How can amino acids, simple sugars, and nucleotides be synthesized abiotically?
B) How can RNA molecules catalyze reactions?
C) How did RNA sequences come to carry the code for amino acid sequences?
D) How could polymers involving lipids and/or proteins form membranes in aqueous environments?
E) How can RNA molecules act as templates for the synthesis of complementary RNA molecules?







Answer: C

The synthesis of new DNA requires the prior existence of oligonucleotides to serve as primers. On Earth, these primers are small RNA molecules. This latter observation is evidence in support of the hypothesized existence of

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The synthesis of new DNA requires the prior existence of oligonucleotides to serve as primers. On Earth, these primers are small RNA molecules. This latter observation is evidence in support of the hypothesized existence of 






A) a snowball Earth.
B) earlier genetic systems than those based on DNA.
C) the abiotic synthesis of organic monomers.
D) the delivery of organic matter to Earth by meteors and comets.
E) the endosymbiotic origin of mitochondria and chloroplasts.







Answer: B

The first genes on Earth were probably

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The first genes on Earth were probably 




A) DNA produced by reverse transcriptase from abiotically produced RNA.
B) DNA molecules whose information was transcribed to RNA and later translated in polypeptides.
C) auto-catalytic RNA molecules.
D) oligopeptides located within protobionts.






Answer: C

Which of the following is the correct sequence of events in the origin of life? I. formation of protobionts II. synthesis of organic monomers III. synthesis of organic polymers IV. formation of DNA-based genetic systems

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Which of the following is the correct sequence of events in the origin of life?
I. formation of protobionts
II. synthesis of organic monomers
III. synthesis of organic polymers
IV. formation of DNA-based genetic systems 







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






Answer: C

What is true of the amino acids that might have been delivered to Earth within carbonaceous chondrites?

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What is true of the amino acids that might have been delivered to Earth within carbonaceous chondrites? 






A) They had the same proportion of L and D isomers as Earth does today.
B) Their abundance would have been dramatically reduced upon passage through early Earth's oxidizing atmosphere.
C) There were more kinds of amino acids on the chondrites than are found in living organisms today.
D) They were delivered in the form of polypeptides.






Answer: C

How were conditions on the early Earth of more than 3 billion years ago different from those on today's Earth?

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How were conditions on the early Earth of more than 3 billion years ago different from those on today's Earth? 






A) Only early Earth was intensely bombarded by large space debris.
B) Only early Earth had an oxidizing atmosphere.
C) Less ultraviolet radiation penetrated early Earth's atmosphere.
D) Early Earth's atmosphere had significant quantities of ozone.






Answer: A

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

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






A) 1 only
B) 2 only
C) 1 and 2
D) 1 and 3
E) 2 and 3






Answer: D

Suppose that a group of male pied flycatchers migrated from a region where there were no collared flycatchers to a region where both species were present. Assuming events like this are very rare, which of the following scenarios is least likely?

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Suppose that a group of male pied flycatchers migrated from a region where there were no collared flycatchers to a region where both species were present. Assuming events like this are very rare, which of the following scenarios is least likely? 






A) The frequency of hybrid offspring would increase.
B) Migrant pied males would produce fewer offspring than would resident pied males.
C) Pied females would rarely mate with collared males.
D) Migrant males would mate with collared females more often than with pied females.
E) The frequency of hybrid offspring would decrease.





Answer: E

Plant species A has a diploid number of 12. Plant species B has a diploid number of 16. A new species, C, arises as an allopolyploid from A and B. The diploid number for species C would probably be

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Plant species A has a diploid number of 12. Plant species B has a diploid number of 16. A new species, C, arises as an allopolyploid from A and B. The diploid number for species C would probably be 







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





Answer: D

Which of the following factors would not contribute to allopatric speciation?

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Which of the following factors would not contribute to allopatric speciation? 






A) A population becomes geographically isolated from the parent population.
B) The separated population is small, and genetic drift occurs.
C) The isolated population is exposed to different selection pressures than the ancestral population.
D) Different mutations begin to distinguish the gene pools of the separated populations.
E) Gene flow between the two populations is extensive.






Answer: E

Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species. Recently, these birds have been classified as eastern and western forms of a single species, the yellow-rumped warbler. Which of the following pieces of evidence, if true, would be cause for this reclassification?

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Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species. Recently, these birds have been classified as eastern and western forms of a single species, the yellow-rumped warbler. Which of the following pieces of evidence, if true, would be cause for this reclassification? 





A) The two forms interbreed often in nature, and their offspring have good survival and reproduction.
B) The two forms live in similar habitats.
C) The two forms have many genes in common.
D) The two forms have similar food requirements.
E) The two forms are very similar in coloration.






Answer: A

According to the punctuated equilibria model,

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According to the punctuated equilibria model, 





A) natural selection is unimportant as a mechanism of evolution.
B) given enough time, most existing species will branch gradually into new species.
C) most new species accumulate their unique features relatively rapidly as they come into existence, then change little for the rest of their duration as a species.
D) most evolution occurs in sympatric populations.
E) speciation is usually due to a single mutation.






Answer: C

Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. These rituals involve fighting other males and making stylized movements that attract females. What type of reproductive isolation does this represent?

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Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. These rituals involve fighting other males and making stylized movements that attract females. What type of reproductive isolation does this represent? 




A) habitat isolation
B) temporal isolation
C) behavioral isolation
D) gametic isolation
E) postzygotic barriers





Answer: C

On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the island's lowlands, and is also found on the African mainland, located about 200 miles away. At higher elevations, and only on Sao Tomé, is found the very closely related Drosophila santomea. The two species can hybridize, though male hybrids are sterile. A hybrid zone exists at middle elevations, though hybrids there are greatly outnumbered by D. santomea. Studies of the two species' nuclear genomes reveal that D. yakuba on the island is more closely related to mainland D. yakuba than to D. santomea (2n = 4 in both species). Sao Tomé rose from the Atlantic Ocean about 14 million years ago

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On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the island's lowlands, and is also found on the African mainland, located about 200 miles away. At higher elevations, and only on Sao Tomé, is found the very closely related Drosophila santomea. The two species can hybridize, though male hybrids are sterile. A hybrid zone exists at middle elevations, though hybrids there are greatly outnumbered by D. santomea. Studies of the two species' nuclear genomes reveal that D. yakuba on the island is more closely related to mainland D. yakuba than to D. santomea (2n = 4 in both species). Sao Tomé rose from the Atlantic Ocean about 14 million years ago 



If the low number of hybrid flies in the hybrid zone, relative to the number of D. santomea flies there, is due to the fact that hybrids are poorly adapted to conditions in the hybrid zone, and if fewer hybrid flies are produced with the passage of time, these conditions will most likely lead to 

A) fusion.
B) reinforcement.
C) stability.
D) further speciation events.
Answer: B



Which two of the following have operated to increase divergence between mosquitofish populations on Andros? 

1. improved gene flow
2. bottleneck effect
3. sexual selection
4. founder effect
5. natural selection

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


Answer: E


Which type of reproductive isolation operates to keep the mosquitofish isolated, even when fish from different ponds are reunited in the same body of water? A) behavioral isolation 

B) habitat isolation
C) temporal isolation
D) mechanical isolation
E) gametic isolation


Answer: A


What is the best way to promote fusion between two related populations of mosquitofish, one of which lives in a predator-rich pond, and the other of which lives in a predator-poor pond? A) Build a canal linking the two ponds that permits free movement of mosquitofish, but not of predators. 

B) Transfer only female mosquitofish from a predator-rich pond to a predator-poor pond.
C) Perform a reciprocal transfer of females between predator-rich and predator-poor ponds.
D) Remove predators from a predator-rich pond and transfer them to a predator-poor pond.


Answer: A


If one builds a canal linking a predator-rich pond to a predator-poor pond, then what type(s) of selection should subsequently be most expected among the mosquitofish in the original predator-rich pond, and what type(s) should be most expected among the mosquitofish in the formerly predator-poor pond? A) stabilizing selection; directional selection 

B) stabilizing selection; stabilizing selection
C) less-intense directional selection; more-intense directional selection
D) less-intense disruptive selection; more-intense disruptive selection


Answer: C


The predatory fish rely on visual cues and speed to capture mosquitofish. Mosquitofish rely on speed and visual cues to avoid the predatory fish. Which adaptation(s) might help the predators survive in ponds that are home to faster mosquitofish? 

1. directional selection for increased speed
2. stabilizing selection for speed that matches that of the mosquitofish
3. change in hunting behavior that replaces reliance on visual cues with reliance on tactile cues, which can be used to hunt at night
4. change in hunting behavior that eliminates speed in favor of better camouflage, which permits an ambush strategy



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



Answer: E

On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the island's lowlands, and is also found on the African mainland, located about 200 miles away. At higher elevations, and only on Sao Tomé, is found the very closely related Drosophila santomea. The two species can hybridize, though male hybrids are sterile. A hybrid zone exists at middle elevations, though hybrids there are greatly outnumbered by D. santomea. Studies of the two species' nuclear genomes reveal that D. yakuba on the island is more closely related to mainland D. yakuba than to D. santomea (2n = 4 in both species). Sao Tomé rose from the Atlantic Ocean about 14 million years ago.

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On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the island's lowlands, and is also found on the African mainland, located about 200 miles away. At higher elevations, and only on Sao Tomé, is found the very closely related Drosophila santomea. The two species can hybridize, though male hybrids are sterile. A hybrid zone exists at middle elevations, though hybrids there are greatly outnumbered by D. santomea. Studies of the two species' nuclear genomes reveal that D. yakuba on the island is more closely related to mainland D. yakuba than to D. santomea (2n = 4 in both species). Sao Tomé rose from the Atlantic Ocean about 14 million years ago. 




Which of the following reduces gene flow between the gene pools of the two species on Sao Tomé, despite the existence of hybrids? 

A) hybrid breakdown
B) hybrid inviability
C) hybrid sterility
D) temporal isolation
E) a geographic barrier


Answer: C


The observation that island D. yakuba are more closely related to mainland D. yakuba than island D. yakuba are to D. santomea is best explained by proposing that D. santomea A) descended from a now-extinct, non-African fruit fly. 

B) arrived on the island before D. yakuba.
C) descended from a single colony of D. yakuba, which had been introduced from elsewhere, with no subsequent colonization events.
D) descended from an original colony of D. yakuba, of which there are no surviving members. The current island D. yakuba represent a second colonization event from elsewhere.


Answer: D


If a speciation event occurred on Sao Tomé, producing D. santomea from a parent colony of D. yakuba, then which terms apply? 

I.macroevolution
IIallopatric speciation
III.sympatric speciation

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


Answer: D

Using only the information provided in the paragraph, which of the following is the best initial hypothesis for how D. santomea descended from D. yakuba? 

A) geographic isolation
B) autopolyploidy
C) habitat differentiation
D) sexual selection
E) allopolyploidy


Answer: C

In order for speciation to occur, what must be true?

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In order for speciation to occur, what must be true? 






A) The number of chromosomes in the gene pool must change.
B) Changes to centromere location or chromosome size must occur within the gene pool.
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) At least one gene, affecting at least one phenotypic trait, must change.







Answer: E

Which of the following statements about speciation is correct?

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Which of the following statements about speciation is correct? 





A) The goal of natural selection is speciation.
B) When reunited, two allopatric populations will interbreed freely if speciation has occurred.
C) Natural selection chooses the reproductive barriers for populations.
D) Prezygotic reproductive barriers usually evolve before postzygotic barriers.
E) Speciation is a basis for understanding macroevolution.







Answer: E

Speciation

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Speciation 






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





Answer: E

According to the concept of punctuated equilibrium,

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According to the concept of punctuated equilibrium, 






A) natural selection is unimportant as a mechanism of evolution.
B) given enough time, most existing species will branch gradually into new species.
C) a new species accumulates most of its unique features as it comes into existence.
D) evolution of new species features long periods during which changes are occurring, interspersed with short periods of equilibrium, or stasis.
E) transitional fossils, intermediate between newer species and their parent species, should be abundant.







Answer: C

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

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






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



Answer: D

A narrow hybrid zone separates the toad species Bombina bombina and Bombina variegata. What is true of those alleles that are unique to the parental species?

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A narrow hybrid zone separates the toad species Bombina bombina and Bombina variegata. What is true of those alleles that are unique to the parental species? 






A) Such alleles should be absent.
B) Their allele frequency should be nearly the same as the allele frequencies in toad populations distant from the hybrid zone.
C) The alleles' heterozygosity should be higher among the hybrid toads there.
D) Their allele frequency on one edge of the hybrid zone should roughly equal their frequency on the opposite edge of the hybrid zone.






Answer: C
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