AP Bio chapter 22-24
In which population would it be least likely that an accident would significantly alter the frequency of the brown allele?
Population B.
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.2. What is the frequency of individuals with Aa genotype?
0.32
You sample a population of butterflies and find that 42% are heterozygous at a particular locus. What should be the frequency of the recessive allele in this population?
0.70
In peas, a gene controls flower color such that R = purple and r = white. In an isolated pea patch, there are 36 purple-flowering plants and 64 white-flowering plants. Assuming Hardy-Weinberg equilibrium, what is the value of q for this population?
0.80
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.4. What is the percentage of the population that is homozygous for this allele?
16
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.1. What is the percentage of the population that is heterozygous for this allele?
18
If the curve shifts to the left or to the right, there is no gene flow, and the population size consequently increases over successive generations, then which of these is (are) probably occurring? 1. immigration or emigration 2. directional selection 3. adaptation 4. genetic drift 5. disruptive selection
2 and 3
Arrange the following from most general (i.e., most inclusive) to most specific (i.e., least inclusive): 1. Natural selection 2. Microevolution 3. Intrasexual selection 4. Evolution 5. Sexual selection A) 4, 1, 2, 3, 5 B) 4, 2, 1, 3, 5 C) 4, 2, 1, 5, 3 D) 1, 4, 2, 5, 3 E) 1, 2, 4, 5, 3
4, 2, 1, 5, 3
Rank the following 1-base point mutations (from most likely to least likely) with respect to their likelihood of affecting the structure of the corresponding polypeptide: 1. insertion mutation deep within an intron 2. substitution mutation at the 3rd position of an exonic codon 3. substitution mutation at the 2nd position of an exonic codon 4. deletion mutation within the first exon of the gene
4, 3, 2, 1
If, on average, 46% of the loci in a species gene pool are heterozygous, then the average homozygosity of the species should be
54%
2) Bird guides once listed the myrtle warbler and Audubonʹs 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.
A
: Application/Analysis 11) Females of one species choose mates based on song quality; females of another species choose mates on the basis of size. A) behavioral B) gametic C) habitat D) temporal E) mechanical
A Topic: Concept 24.1
: Application/Analysis 6) A biologist discovers two populations of wolf spiders whose members appear identical. Members of one population are found in the leaf litter deep within the woods. Members of the other population are found in the grass at the edge of the woods. The biologist decides to designate the members of the two populations as two separate species. Which species concept is this biologist most closely utilizing? A) ecological B) biological C) morphological D) phylogenetic
A Topic: Concept 24.1
: Application/Analysis The questions below are based on the following description. Several closely related frog species of the genus Rana are found in the forests of the southeastern United States. The species boundaries are maintained by reproductive barriers. In each case, match the various descriptions of frogs below with the appropriate reproductive barrier listed. 9) Males of one species sing only when its predators are absent; males of another species sing only when its predators are present. A) behavioral B) gametic C) habitat D) temporal E) mechanical
A Topic: Concept 24.1
: Knowledge/Comprehension 2) What is generally true of two very closely related species that have diverged from each other quite recently? A) They shared a common ancestor recently in evolutionary time. B) Genes are unable to pass from one speciesʹ gene pool to the otherʹs gene pool. C) They are unable to produce hybrid offspring upon interbreeding. D) Their reproductive isolation from each other is complete.
A Topic: Concept 24.1
: Synthesis/Evaluation Chapter 24, The Origin of Species 475 16) Two species of frogs belonging to the same genus occasionally mate, but the offspring fail to develop and hatch. What is the mechanism for keeping the two frog species separate? A) the postzygotic barrier called hybrid inviability B) the postzygotic barrier called hybrid breakdown C) the prezygotic barrier called hybrid sterility D) gametic isolation E) adaptation
A Topic: Concept 24.1
:Knowledge/Comprehension 4) Which species concept is currently most popular among most biologists? A) phylogenetic B) ecological C) biological D) morphological
A Topic: Concept 24.1
: Knowledge/Comprehension 25) The difference between geographic isolation and habitat differentiation is the A) relative locations of two populations as speciation occurs. B) speed (tempo) at which two populations undergo speciation. C) amount of genetic variation that occurs among two gene pools as speciation occurs. D) identity of the phylogenetic kingdom or domain in which these phenomena occur. E) the ploidy of the two populations as speciation occurs.
A Topic: Concept 24.2
: Application/Analysis 484 Chapter 24, The Origin of Species 43) The results depicted in the graphs above are best accounted for by which of the following facts? A) The Colorado River has been an effective geographic barrier to these two types of squirrels for several million years. B) There is more white fur on the tails of the northern squirrels than on the tails of the southern squirrels. C) Both types of squirrel subsist largely on a diet of pine nuts and juniper seeds in this ecosystem. D) Both types of squirrel share the same common ancestor. E) Both types of squirrel are active during the day.
A Topic: Concept 24.3
: Knowledge/Comprehension 32) Which of these should decline in hybrid zones where reinforcement is occurring? A) gene flow between distinct gene pools B) speciation C) the genetic distinctness of two gene pools D) mutation rate E) hybrid sterility
A Topic: Concept 24.3
: Knowledge/Comprehension 33) The most likely explanation for the high rate of sympatric speciation that apparently existed among the cichlids of Lake Victoria in the past is A) sexual selection. B) habitat differentiation. C) polyploidy. D) pollution. E) introduction of a new predator.
A Topic: Concept 24.3
: Knowledge/Comprehension 46) Which of the following would be a position held by an adherent of the punctuated equilibrium theory? A) A new species forms most of its unique features as it comes into existence and then changes little for the duration of its existence. B) One should expect to find many transitional fossils left by organisms in the process of forming new species. C) Given enough time, most existing species will gradually evolve into new species. D) Natural selection is unimportant as a mechanism of evolution.
A Topic: Concept 24.4
: Knowledge/Comprehension 486 Chapter 24, The Origin of Species The following questions refer to the evolutionary tree below, whose horizontal axis represents time (present time is on the far right) and whose vertical axis represents morphological change. Figure 24.1 51) Which of these five species (V—Z) in the evolutionary tree would likely have fossil records indicating that punctuated equilibrium was an important part of their evolutionary history? A) V and W B) V and Y C) X and Y D) W, Y, and Z E) X, Y, and Z
A Topic: Concept 24.4
: Synthesis/Evaluation 54) Which of these five species is the extant (i.e., not extinct) species that is most closely related to species X, and why is this so? A) V; shared a common ancestor with X most recently B) W; shared a common ancestor with X most recently C) Y; arose in the same fashion (i.e., at the same tempo) as X D) Z; shared a common ancestor with X most recently, and arose in the same fashion as X E) This tree does not provide enough information to answer this question.
A Topic: Concept 24.4
: Synthesis/Evaluation 40) Which of these evolutionary trees represents the situation described in the paragraph above (NOTE: yakuba (I) represents the island population, and yakuba (M) represents the mainland population)? A) B) 482 Chapter 24, The Origin of Species C) D)
A Topic: Concepts 22.3, 24.1
The higher the proportion of loci that are fixed in a population, the lower is that populations
A and C only
There are those who claim that the theory of evolution cannot be true because the apes, which are supposed to be closely related to humans, do not likewise share the same large brains, capacity for complicated speech, and tool-making capability. They reason that if these features are generally beneficial, then the apes should have evolved them as well. Which of these provides the best argument against this misconception?
Advantageous alleles do not arise on demand
Which of these variables is likely to undergo the largest change in value as the result of a mutation that introduces a brand-new allele into a population s gene pool at a locus that had formerly been fixed?
Average heterozygosity
: Application/Analysis 488 Chapter 24, The Origin of Species Self-Quiz Questions The following questions are from the end-of-chapter-review Self-Quiz questions in Chapter 24 of the textbook. 1) The largest unit within which gene flow can readily occur is a A) population. B) species. C) genus. D) hybrid. E) phylum.
B
: Application/Analysis 15) Rank the following from most general to most specific: 1. gametic isolation 2. reproductive isolating mechanism 3. pollen-stigma incompatibility 4. prezygotic isolating mechanism A) 2, 3, 1, 4 B) 2, 4, 1, 3 C) 4, 1, 2, 3 D) 4, 2, 1, 3 E) 2, 1, 4, 3
B Topic: Concept 24.1
: Application/Analysis 7) What was the species concept most used by Linnaeus? A) biological B) morphological C) ecological D) phylogenetic
B Topic: Concept 24.1
: Knowledge/Comprehension 476 Chapter 24, The Origin of Species 20) Races of humans are unlikely to evolve extensive differences in the future for which of the following reasons? I. The environment is unlikely to change. II. Human evolution is complete. III. The human races are incompletely isolated. A) I only B) III only C) I and II only D) II and III only E) I, II, and III
B Topic: Concept 24.2
: Knowledge/Comprehension 478 Chapter 24, The Origin of Species 27) Beetle pollinators of a particular plant are attracted to its flowersʹ bright orange color. The beetles not only pollinate the flowers, but they mate while inside of the flowers. A mutant version of the plant with red flowers becomes more common with the passage of time. A particular variant of the beetle prefers the red flowers to the orange flowers. Over time, these two beetle variants diverge from each other to such an extent that interbreeding is no longer possible. What kind of speciation has occurred in this example, and what has driven it? A) allopatric speciation, ecological isolation B) sympatric speciation, habitat differentiation C) allopatric speciation, behavioral isolation D) sympatric speciation, sexual selection E) sympatric speciation, allopolyploidy
B Topic: Concept 24.2
: Application/Analysis 41) 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, this is most likely to lead to A) fusion. B) reinforcement. C) stability. D) further speciation events.
B Topic: Concept 24.3
: Knowledge/Comprehension 34) The most likely explanation for the recent decline in cichlid species diversity in Lake Victoria is A) reinforcement. B) fusion. C) stability. D) geographic isolation. E) polyploidy.
B Topic: Concept 24.3
: Knowledge/Comprehension Chapter 24, The Origin of Species 479 31) A hybrid zone is properly defined as A) an area where two closely related speciesʹ ranges overlap. B) an area where mating occurs between members of two closely related species, producing viable offspring. C) a zone that features a gradual change in species composition where two neighboring ecosystems border each other. D) a zone that includes the intermediate portion of a cline. E) an area where members of two closely related species intermingle, but experience no gene flow.
B Topic: Concept 24.3
: Application/Analysis 52) Which of these five species originated earliest and appeared suddenly in the fossil record? A) V B) W C) X D) Y E) Z
B Topic: Concept 24.4
: Application/Analysis 28) The origin of a new plant species by hybridization, coupled with accidents during nuclear division, is an example of A) allopatric speciation. B) sympatric speciation. C) autopolyploidy. D) habitat selection.
B Topic: Concepts 24.2
In a hypothetical population s gene pool, an autosomal gene, which had previously been fixed, undergoes a mutation that introduces a new allele, one inherited according to incomplete dominance. Natural selection then causes stabilizing selection at this locus. Consequently, what should happen over the course of many generations? A) The proportions of both types of homozygote should decrease. B) The proportion of the population that is heterozygous at this locus should remain constant. C) The population s average heterozygosity should increase. D) Both (A)and (B) E) Both (A)and (C)
Both (A)and (C)
3) Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian islands have different elaborate courtship rituals that involve fighting other males and 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
C
6) 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.
C
: Knowledge/Comprehension 3) Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools? A) phylogenetic B) ecological C) biological D) morphological
C
1) 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 reproduction is possible. A) I only B) II only C) I and III D) II and III E) I, II, and III
C Topic: Concept 24.1
: Application/Analysis 10) One species lives only in tree holes; another species lives only in streams. A) behavioral B) gametic C) habitat D) temporal E) mechanical
C Topic: Concept 24.1
: Knowledge/Comprehension 17) Theoretically, the production of sterile mules by interbreeding between female horses and male donkeys should A) result in the extinction of one of the two parental species. B) cause convergent evolution. C) strengthen postzygotic barriers between horses and donkeys. D) weaken the intrinsic reproductive barriers between horses and donkeys. E) eventually result in the formation of a single species from the two parental species.
C Topic: Concept 24.1
: Knowledge/Comprehension 18) The biological species concept is inadequate for grouping A) plants. B) parasites. C) asexual organisms. D) animals that migrate. E) sympatric populations.
C Topic: Concept 24.1
: Knowledge/Comprehension The following questions refer to the description below. On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the islandʹs lowlands, and is also found on the African mainland, located about 200 miles away. At higher elevations, and found 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 speciesʹ 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. 36) Which of these 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
C Topic: Concept 24.1
: Application/Analysis 22) A defining characteristic of allopatric speciation is A) the appearance of new species in the midst of old ones. B) asexually reproducing populations. C) geographic isolation. D) artificial selection. E) large populations.
C Topic: Concept 24.2
: Application/Analysis 39) Using only the information provided in the paragraph, which of these 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
C Topic: Concept 24.2
: Knowledge/Comprehension Chapter 24, The Origin of Species 477 24) Two closely related populations of mice have been separated for many generations by a river. Climatic change causes the river to dry up, thereby bringing the mice populations back into contact in a zone of overlap. Which of the following is not a possible outcome when they meet? A) They interbreed freely and produce fertile hybrid offspring. B) They no longer attempt to interbreed. C) They interbreed in the region of overlap, producing an inferior hybrid. Subsequent interbreeding between inferior hybrids produces progressively superior hybrids over several generations. D) They remain separate in the extremes of their ranges but develop a persistent hybrid zone in the area of overlap. E) They interbreed in the region of overlap, but produce sterile offspring.
C Topic: Concept 24.2
: Knowledge/Comprehension 45) 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.
C Topic: Concept 24.4
: Knowledge/Comprehension 480 Chapter 24, The Origin of Species 35) In the narrow hybrid zone that 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 allelesʹ 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.
C Topic: Concepts 23.1, 24.3
: Knowledge/Comprehension 49) Upon undergoing change, which of these genes is most likely to result in speciation while a geographic barrier separates two populations of a flowering-plant species? A) one that affects the rate of chlorophyll a synthesis B) one that affects the amount of growth hormone synthesized per unit time C) one that affects the compatibility of male pollen and female reproductive parts D) one that affects the average depth to which roots grow down through the soil E) one that affects how flexible the stems are
C Topic: Concepts 24.1, 24.4
5) 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.
D
: Application/Analysis 14) Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms? A) reduced hybrid fertility B) hybrid breakdown C) mechanical isolation D) habitat isolation E) gametic isolation
D Topic: Concept 24.1
: Application/Analysis 474 Chapter 24, The Origin of Species 12) One species mates at the season when daylight is increasing from 13 hours to 13 hours, 15 minutes; another species mates at the season when daylight is increasing from 14 hours to 14 hours, 15 minutes. A) behavioral B) gametic C) habitat D) temporal E) mechanical
D Topic: Concept 24.1
: Knowledge/Comprehension 5) There is still some controversy among biologists about whether Neanderthals should be placed within the same species as modern humans, or into a separate species of their own. Most DNA sequence data analyzed so far indicate that there was probably little or no gene flow between Neanderthals and Homo sapiens. Which species concept is most applicable in this example? A) phylogenetic B) ecological C) morphological D) biological
D Topic: Concept 24.1
: Knowledge/Comprehension Chapter 24, The Origin of Species 473 8) You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use? A) biological B) phylogenetic C) ecological D) morphological
D Topic: Concept 24.1
: Knowledge/Comprehension 23) A rapid method of speciation that has been important in the history of flowering plants is A) genetic drift. B) a mutation in the gene controlling the timing of flowering. C) behavioral isolation. D) polyploidy.
D Topic: Concept 24.2
: Knowledge/Comprehension Among known plant species, which of these have been the two most commonly occurring phenomena leading to the origin of new species? 1. allopatric speciation 2. sympatric speciation 3. sexual selection 4. polyploidy A) 1 and 3 B) 1 and 4 C) 2 and 3 D) 2 and 4
D Topic: Concept 24.2
: Knowledge/Comprehension 29) The phenomenon of fusion is likely to occur when, after a period of geographic isolation, two populations meet again and A) their chromosomes are no longer homologous enough to permit meiosis. B) a constant number of viable, fertile hybrids is produced over the course of generations. C) the hybrid zone is inhospitable to hybrid survival. D) an increasing number of viable, fertile hybrids is produced over the course of generations E) a decreasing number of viable, fertile hybrids is produced over the course of generations.
D Topic: Concept 24.3
: Knowledge/Comprehension 30) The constantly changing nature of the Appalachian ground crickets (Allonemobius fasciatus and Allonemobius socius) hybrid zone favors A) no gene flow between the two gene pools. B) little gene flow between the two gene pools. C) increased levels of gene flow between the two gene pools. D) extinction of both species as the hybrids persist.
D Topic: Concept 24.3
: Knowledge/Comprehension 37) 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) arose de novo; that is, had no ancestors. 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.
D Topic: Concept 24.3
: Synthesis/Evaluation The following questions refer to the paragraph and graphs below. In a hypothetical situation, the National Park Service, which administers Grand Canyon National Park in Arizona, builds a footbridge over the Colorado River at the bottom of the canyon. The footbridge permits interspersal of two closely related antelope squirrels. Previously, one type of squirrel had been restricted to the terrain south of the river, and the other type had been restricted to terrain on the north side of the river. Immediately before and ten years after the bridgeʹs completion, ten antelope squirrels from both sides of the river were collected, blood samples were taken, and frequencies of alleles unique to the two types of antelope squirrels were determined (see graphs below). Chapter 24, The Origin of Species 483 42) The data in the graphs above indicate that A) a hybrid zone was established after the completion of the bridge. B) no interspersal of the two types of squirrel occurred after the completion of the bridge. C) gene flow occurred from one type of squirrel into the gene pool of the other type of squirrel. D) 2-way migration of squirrels occurred across the bridge, but without hybridization. E) some northern squirrels migrated south, but no southern squirrels migrated north across the bridge.
D Topic: Concept 24.3
: Application/Analysis Chapter 24, The Origin of Species 487 53) Which conclusion can be drawn from this evolutionary tree? A) Gradualistic speciation and speciation involving punctuated equilibrium are mutually exclusive concepts; only one of them can occur. B) Eldredge and Gould would deny that the lineages labeled X, Y, and Z could represent true species. C) Assuming that the tip of each line represents a species, there are five extant (i.e., not extinct) species resulting from the earliest common ancestor. D) A single clade (i.e., a group of species that share a common ancestor) can exhibit both gradualism and punctuated equilibrium. E) V and W shared a common ancestor more recently than any of the other species.
D Topic: Concept 24.4
: Synthesis/Evaluation 44) According to the concept of punctuated equilibrium, the ʺsuddenʺ 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.
D Topic: Concept 24.4
: Synthesis/Evaluation Chapter 24, The Origin of Species 481 38) If a speciation event occurred on Sao Tomé, producing D. santomea from a parent colony of D. yakuba, then which terms apply? I. macroevolution II. allopatric speciation III. sympatric speciation A) I only B) II only C) I & II D) I & III
D Topic: Concepts 24.1, 24.2
Cattle breeders have improved the quality of meat over the years by which process? A) artificial selection B) directional selection C) stabilizing selection D) A and B E) A and C
D) A and B
Sponges are known to contain a single Hox gene. Most invertebrates have a cluster of 10 similar Hox genes, all located on the same chromosome. Most vertebrates have four such clusters of Hox genes, located on four non-homologous chromosomes. The process responsible for the change in number of Hox genes from sponges to invertebrates was most likely __________, whereas a different process that could have potentially contributed to the cluster s presence on more than one chromosome was __________. I. binary fission II. translation III. gene duplication IV. non-disjunction V. transcription
D) III, IV
You are studying three populations of birds. Population A has ten birds, of which one is brown (a recessive trait) and nine are red. Population B has 100 birds, of which ten are brown. Population C has 30 birds, and three of them are brown. 39) In which population is the frequency of the allele for brown feathers highest? A) Population A. B) Population B. C) Population C. D) They are all the same. E) It is impossible to tell from the information given.
D) They are all the same.
4) 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.
E
: Application/Analysis 13) Males of one species are too small to perform amplexus (an action that stimulates ovulation) with females of all other species. A) behavioral B) gametic C) habitat D) temporal E) mechanical
E Topic: Concept 24.1
: Knowledge/Comprehension 19) Which example below will most likely guarantee that two closely related species will persist only as distinct biological species? A) colonization of new habitats B) convergent evolution C) hybridization D) geographic isolation from one another E) reproductive isolation from one another
E Topic: Concept 24.1
: Knowledge/Comprehension 48) Which of the following statements about speciation is correct? A) The goal of natural selection is speciation. B) When reunited, two allopatric populations will not interbreed. 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.
E Topic: Concept 24.4
: Knowledge/Comprehension Chapter 24, The Origin of Species 485 47) 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) proceeds at a uniform tempo across all taxa. E) can involve changes involving a single gene.
E Topic: Concept 24.4
: Synthesis/Evaluation 50) In order for speciation to occur, what is true? A) The number of chromosomes in the genome must change. B) Changes to centromere location or chromosome size must occur within the genome. 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.
E Topic: Concept 24.4
: Knowledge/Comprehension 21) In a hypothetical situation, a certain species of flea feeds only on pronghorn antelopes. In rangelands of the western United States, pronghorns and cattle often associate with one another. If some of these fleas develop a strong preference, instead, for cattle blood and mate only with fleas that, likewise, prefer cattle blood, then over time which of these should occur, if the host mammal can be considered as the fleasʹ habitat? 1. reproductive isolation 2. sympatric speciation 3. habitat isolation 4. prezygotic barriers A) 1 only B) 2 and 3 C) 1, 2, and 3 D) 2, 3, and 4 E) 1 through 4
E Topic: Concepts 24.1, 24.2
If the frequency of a particular allele that is present in a small, isolated population of alpine plants decreases due to a landslide that leaves an even smaller remnant of surviving plants bearing this allele, then what has occurred? A) a bottleneck B) genetic drift C) microevolution D) A and B only E) A, B, and C
E) A, B, and C
If the original finches that had been blown over to the Galapagos from South America had already been genetically different from the parental population of South American finches, even before adapting to the Galapagos, this would have been an example of A) genetic drift. B) bottleneck effect. C) founder s effect. D) all three of these E) both A and C
E) both A and C
Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is true?
Each bird s survival was strongly influenced by the depth and strength of its beak as the drought persisted.
Each of the following has a better chance of influencing gene frequencies in small populations than in large populations, but which one most consistently requires a small population as a precondition for its occurrence?
Genetic drift
Which addition to the information in the paragraph above would make more than one of the answers listed in the previous question correct?
If females killed female offspring whose voices were too deep.
Which of the following statements best summarizes evolution as it is viewed today?
It is the differential survival and reproduction of the most-fit phenotypes.
Which is a true statement concerning genetic variation?
It must be present in a population before natural selection can act upon the population.
Over the course of evolutionary time, what should occur?
Methylated and nonmethylated strains should be maintained among both bacteria and bacteriophages, with ratios that vary over time.
Which of these evolutionary agents is most consistent at causing populations to become better suited to their environments over the course of generations?
Natural selection
If two genes from one RNA molecule become detached and then, as a unit, get attached to one end of the other RNA molecule within a single HIV particle, which of these is true?
One of the RNA molecules has experienced gene duplication as the result of translocation.
The same gene that causes various coat patterns in wild and domesticated cats also causes the cross-eyed condition in these cats, the cross-eyed condition being slightly maladaptive. In a hypothetical environment, the coat pattern that is associated with crossed eyes is highly adaptive, with the result that both the coat pattern and the cross-eyed condition increase in a feline population over time. Which statement is supported by these observations?
Phenotype is often the result of compromise.
Which population is most likely to be subject to the bottleneck effect?
Population A.
Which of these makes determining the evolutionary relatedness of different species based on the amino acid sequence of homologous proteins generally less accurate than determinations of relatedness based on the nucleotide sequences of homologous genes?
Silent mutations
Which of these is a statement that Darwin would have rejected?
The smallest entity that can evolve is an individual organism.
Mules are relatively long-lived and hardy organisms that cannot, generally speaking, perform successful meiosis. Consequently, which statement about mules is true?
They have a relative evolutionary fitness of zero.
Which definition of evolution would have been most foreign to Charles Darwin during his lifetime?
change in gene frequency in gene pools
A trend toward the decrease in the size of plants on the slopes of mountains as altitudes increase is an example of
a cline.
Which of these is the smallest unit that natural selection can change?
a population's gene frequency
Which of these is the smallest unit upon which natural selection directly acts?
an individual's phenotype
You are maintaining a small population of fruit flies in the laboratory by transferring the flies to a new culture bottle after each generation. After several generations, you notice that the viability of the flies has decreased greatly. Recognizing that small population size is likely to be linked to decreased viability, the best way to reverse this trend is to
cross your flies with flies from another lab
A certain species of land snail exists as either a cream color or a solid brown color. Intermediate individuals are relatively rare. Which of the following terms best describes this?
disruptive selection
Which describes an African butterfly species that exists in two strikingly different color patterns?
disruptive selection
Natural selection is most nearly the same as
differential reproductive success.
The recessive allele that causes phenylketonuria (PKU) is harmful, except when an infant s diet lacks the amino acid, phenylalanine. What maintains the presence of this harmful allele in a population s gene pool?
diploidy
Fossil evidence indicates that horses have gradually increased in size over geologic time. Which of the following terms best describes this?
directional selection
In seedcracker finches from Cameroon, small- and large-billed birds specialize in cracking soft and hard seeds, respectively. If long-term climatic change resulted in all seeds becoming hard, what type of selection would then operate on the finch population?
directional selection
If one excludes the involvement of gender in the situation described in the paragraph above, then the pattern that is apparent in the fossil record is most similar to one that should be expected from
disruptive selection.
The restriction enzymes of bacteria protect the bacteria from successful attack by bacteriophages, whose genomes can be degraded by the restriction enzymes. The bacterial genomes are not vulnerable to these restriction enzymes because bacterial DNA is methylated. This situation selects for bacteriophages whose genomes are also methylated. As new strains of resistant bacteriophages become more prevalent, this in turn selects for bacteria whose genomes are not methylated and whose restriction enzymes instead degrade methylated DNA. ) The outcome of the conflict between bacteria and bacteriophage at any point in time results from
frequency-dependent selection.
When imbalances occur in the sex ratio of sexual species that have two sexes (i.e., other than a 50:50 ratio), the members of the minority sex often receive a greater proportion of care and resources from parents than do the offspring of the majority sex. This is most clearly an example of
frequency-dependent selection.
Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing
gene flow.
The DNA polymerases of all cellular organisms have proofreading capability. This capability tends to reduce the introduction of
genetic variation by mutations.
Sexual dimorphism is most often a result of
intersexual selection.
When we say that an individual organism has a greater fitness than another individual, we specifically mean that the organism
leaves more viable offspring than others of its species.
In modern terminology, diversity is understood to be a result of genetic variation. Sources of variation for evolution include all of the following except
mistakes in translation of structural genes.
A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. That the actual forelimbs of these mammals do not seem to be optimally arranged is because
natural selection is generally limited to modifying structures that were present in previous generations and in previous species.
If neutral variation is truly neutral, then it should have no effect on
relative fitness.
Gene flow is a concept best used to describe an exchange between
populations.
Adult male humans generally have deeper voices than do adult female humans, as the direct result of higher levels of testosterone causing growth of the larynx. ) If the fossil records of apes and humans alike show a trend toward decreasing larynx size in adult females, and increasing larynx size in adult males, then
sexual dimorphism was developing over time in these species.
Which describes brightly colored peacocks mating more frequently than drab peacocks?
sexual selection
Male satin bowerbirds adorn structures that they build, called bowers, with parrot feathers, flowers, and other bizarre ornaments in order to attract females. Females inspect the bowers and, if suitably impressed, allow males to mate with them. The evolution of this male behavior is due to
sexual selection.
Heterozygote advantage should be most closely linked to which of the following?
stabilizing selection
Most Swiss starlings produce four to five eggs in each clutch. Those producing fewer or more than this have reduced fitness. Which of the following terms best describes this?
stabilizing selection
The average birth weight for human babies is about 3 kg. Which of the following terms best describes this?
stabilizing selection
The Darwinian fitness of an individual is measured most directly by
the number of its offspring that survive to reproduce.
About which of these did Darwin have a poor understanding?
the sources of genetic variations among individuals
