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242 Cards in this Set
- Front
- Back
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1) Which of the following statements best describes theories?
A) They are nearly the same things as hypotheses. B) They are supported by, and make sense of, many observations. C) They cannot be tested because the described events occurred only once. D) They are predictions of future events. |
B
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2) Catastrophism, meaning the regular occurrence of geological or meteorological disturbances (catastrophes), was Cuvier's attempt to explain the existence of
A) evolution. B) the fossil record. C) uniformitarianism. D) the origin of new species. E) natural selection. |
B
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3) With what other idea of his time was Cuvier's theory of catastrophism most in conflict?
A) gradualism B) the fixity of species C) island biogeography D) uniformitarianism E) the scala naturae |
D
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4) What was the prevailing belief prior to the time of Lyell and Darwin?
A) Earth is a few thousand years old, and populations are unchanging. B) Earth is a few thousand years old, and populations gradually change. C) Earth is millions of years old, and populations rapidly change. D) Earth is millions of years old, and populations are unchanging. E) Earth is millions of years old, and populations gradually change. |
A
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6) Which of the following is the most accurate summary of Cuvier's consideration of fossils found in the vicinity of Paris?
A) extinction of species yes; evolution of new species yes B) extinction of species no; evolution of new species yes C) extinction of species yes; evolution of new species no D) extinction of species no; evolution of new species yes |
C
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7) In the mid-1900s, the Soviet geneticist Lysenko believed that his winter wheat plants, exposed to ever-colder temperatures, would eventually give rise to ever more cold-tolerant winter wheat. Lysenko's attempts in this regard were most in agreement with the ideas of
A) Cuvier. B) Hutton. C) Lamarck. D) Darwin. E) Lyell. |
c
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9) Which of these conditions should completely prevent the occurrence of natural selection in a population over time?
A) All variation between individuals is due only to environmental factors. B) The environment is changing at a relatively slow rate. C) The population size is large. D) The population lives in a habitat where there are no competing species present. |
A
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10) Natural selection is based on all of the following except
A) genetic variation exists within populations. B) the best-adapted individuals tend to leave the most offspring. C) individuals who survive longer tend to leave more offspring than those who die young. D) populations tend to produce more individuals than the environment can support. E) individuals adapt to their environments and, thereby, evolve. |
E
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12) Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection?
1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship. A) 2 → 4 → 1 → 3 B) 4 → 2 → 1 → 3 C) 4 → 1 → 2 → 3 D) 4 → 2 → 3 → 1 E) 2 → 4 → 3 → 1 |
A
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14) Which of the following must exist in a population before natural selection can act upon that population?
A) genetic variation among individuals B) variation among individuals caused by environmental factors C) sexual reproduction D) Three of the responses are correct. E) Two of the responses are correct. |
A
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17) The role that humans play in artificial selection is to
A) determine who lives and who dies. B) create the genetic variants, which nature then selects. C) choose which organisms breed, and which do not. D) train organisms to breed more successfully. E) perform artificial insemination. |
C
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19) The rise of methicillin-resistant Staphylococcus aureus (MRSA) can be considered to be an example of artificial selection because
A) humans purposefully raise MRSA in large fermenters in an attempt to make the bacteria ever-more resistant. B) S. aureus is cultivated by humans to replenish the soil with nutrients. C) humans synthesize methicillin and create environments in which bacteria frequently come into contact with methicillin. D) Humans are becoming resistant to bacteria by taking methicillin. |
C
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22) If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, then what should happen in environments from which antibiotics are missing?
A) These genes should continue to be maintained in case the antibiotics ever appear. B) These bacteria should be outcompeted and replaced by bacteria that have lost these genes. C) The bacteria should try to make the cost worthwhile by locating, and migrating to, microenvironments where traces of antibiotics are present. D) The bacteria should start making and secreting their own antibiotics. |
B
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24) If two modern organisms are distantly related in an evolutionary sense, then one should expect that
A) they live in very different habitats. B) they should share fewer homologous structures than two more closely related organisms. C) their chromosomes should be very similar. D) they shared a common ancestor relatively recently. E) they should be members of the same genus. |
B
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25) Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities?
A) by identifying the bones as being homologous structures B) by the principle of convergent evolution C) by proposing that humans, bats, and dolphins share a common ancestor D) Three of the statements above are correct. E) Two of the statements above are correct. |
E
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27) Which of the following pieces of evidence most strongly supports the common origin of all life on Earth?
A) All organisms require energy. B) All organisms use essentially the same genetic code. C) All organisms reproduce. D) All organisms show heritable variation. E) All organisms have undergone evolution. |
B
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34) What is true of pseudogenes?
A) They are composed of RNA, rather than DNA. B) They are the same things as introns. C) They are unrelated genes that code for the same gene product. D) They are vestigial genes. |
D
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37) A high degree of endemism is most likely in environments that are
A) easily reached and heterogeneous. B) isolated and heterogeneous. C) isolated and homogeneous. D) isolated and extremely cold. E) easily reached and homogeneous. |
B
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1) During an individual organism's lifetime, which of these is most likely to help the organism respond properly to changes in its environment?
A) microevolution B) change in allele or gene frequency C) change in gene expression D) change in average heterozygosity |
C
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3) 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?
A) average heterozygosity B) nucleotide variability C) geographic variability D) average number of loci |
A
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5) Although each of the following has a better chance of influencing gene frequencies in small populations than in large populations, which one most consistently requires a small population as a precondition for its occurrence?
A) mutation B) nonrandom mating C) genetic drift D) natural selection E) gene flow |
C
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6) In modern terminology, diversity is understood to be a result of genetic variation. Which of the following is a recognized source of variation for evolution?
A) mistakes in translation of structural genes B) mistakes in protein folding C) rampant changes to the dictionary of the genetic code D) binary fission E) recombination by crossing over in meiosis |
E
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7) A trend toward the decrease in the size of plants on the slopes of mountains as altitudes increase is an example of
A) a cline. B) a bottleneck. C) relative fitness. D) genetic drift. E) geographic variation. |
A
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8) The higher the proportion of loci that are "fixed" in a population, the lower is that population's
A) nucleotide variability only. B) genetic polyploidy only. C) average heterozygosity only. D) nucleotide variability, average heterozygosity, and genetic polyploidy. E) nucleotide variability and average heterozygosity only. |
E
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9) Which statement about variation is true?
A) All phenotypic variation is the result of genotypic variation. B) All genetic variation produces phenotypic variation. C) All nucleotide variability results in neutral variation. D) All new alleles are the result of nucleotide variability. E) All geographic variation results from the existence of clines. |
D
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10) Rank the following one-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 third position of an exonic codon 3. substitution mutation at the second position of an exonic codon 4. deletion mutation within the first exon of the gene A) 1, 2, 3, 4 B) 4, 3, 2, 1 C) 2, 1, 4, 3 D) 3, 1, 4, 2 E) 2, 3, 1, 4 |
B
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11) 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 nonhomologous chromosomes. The process that could have potentially contributed to the cluster's presence on more than one chromosome was ________.
A) binary fission B) translation C) gene duplication D) nondisjunction E) transcription |
D
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14) Whenever diploid populations are in Hardy-Weinberg equilibrium at a particular locus
A) the allele's frequency should not change from one generation to the next, but its representation in homozygous and heterozygous genotypes may change. B) natural selection, gene flow, and genetic drift are acting equally to change an allele's frequency. C) this means that, at this locus, two alleles are present in equal proportions. D) the population itself is not evolving, but individuals within the population may be evolving. |
A
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15) In the formula for determining a population's genotype frequencies, the 2 in the term 2pq is necessary because
A) the population is diploid. B) heterozygotes can come about in two ways. C) the population is doubling in number. D) heterozygotes have two alleles. |
B
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16) In the formula for determining a population’s genotype frequencies, the pq in the term 2pq is necessary because
A) the population is diploid. B) heterozygotes can come about in two ways. C) the population is doubling in number. D) heterozygotes have two alleles. |
D
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17) Hardy-Weinberg equilibrium must occur in populations wherein
A) an allele remains fixed. B) no genetic variation exists. C) natural selection is not operating. D) All three of the responses above are correct. E) Only two of the responses above are correct. |
E
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23) Evolution
A) must happen, due to organisms’ innate desire to survive. B) must happen whenever a population is not well-adapted to its environment. C) can happen whenever any of the conditions for Hardy-Weinberg equilibrium are not met. D) requires the operation of natural selection. E) requires that populations become better suited to their environments. |
C
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24) Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing
A) nonrandom mating. B) geographic isolation. C) genetic drift. D) gene flow. |
D
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The production of new types of flu virus in the manner described above is most similar to the phenomenon of
A) bottleneck effect. B) founder effect. C) natural selection. D) gene flow. E) sexual selection. |
D
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26) If the original finches that had been blown over to the Galápagos from South America had already been genetically different from the parental population of South American finches, even before adapting to the Galápagos, this would have been an example of
A) genetic drift. B) bottleneck effect. C) founder effect. D) all three of these. E) both the first and third of these. |
E
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27) What is true of natural selection?
A) Natural selection is a random process. B) Natural selection creates beneficial mutations. C) The only way to eliminate harmful mutations is through natural selection. D) Mutations occur at random; natural selection can preserve and distribute beneficial mutations. E) 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. |
D
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31) Sexual dimorphism is most often a result of
A) pansexual selection. B) stabilizing selection. C) intrasexual selection. D) intersexual selection. E) artificial selection. |
D
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33) During breeding season, one should expect female house finches to prefer to mate with males with the brightest red feathers. Which of the following terms are appropriately applied to this situation?
A) sexual selection B) mate choice C) intersexual selection D) Three of the responses are correct. E) Two of the responses are correct. |
D
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34) Adult male humans generally have deeper voices than do adult female humans, which is 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
A) sexual dimorphism was developing over time in these species. B) intrasexual selection seems to have occurred. C) stabilizing selection was occurring in these species concerning larynx size. D) selection was acting more directly upon genotype than upon phenotype. |
A
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37) Which of the following is most likely to produce an African butterfly species in the wild whose members have one of two strikingly different color patterns?
A) artificial selection B) directional selection C) stabilizing selection D) disruptive selection E) sexual selection |
D
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38) 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?
A) artificial selection B) directional selection C) stabilizing selection D) disruptive selection E) sexual selection |
C
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39) 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?
A) heterozygote advantage B) stabilizing selection C) diploidy D) balancing selection |
C
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40) Heterozygote advantage should be most closely linked to which of the following?
A) sexual selection B) stabilizing selection C) random selection D) directional selection E) disruptive selection |
B
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41) 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?
A) disruptive selection B) directional selection C) stabilizing selection D) No selection would operate because the population is in Hardy-Weinberg equilibrium. |
B
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42) 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
A) sexual selection. B) disruptive selection. C) balancing selection. D) stabilizing selection. E) frequency-dependent selection. |
E
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68) If one assumes that Hardy-Weinberg equilibrium applies to the population of colonists on this planet, about how many people will have attached earlobes when the planet's population reaches 10,000?
A) 100 B) 400 C) 800 D) 1,000 E) 10,000 |
A
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1) What is true of macroevolution?
A) It is the same as microevolution, but includes the origin of new species. B) It is evolution above the species level. C) It is defined as the evolution of microscopic organisms into organisms that can be seen with the naked eye. D) It is defined as a change in allele or gene frequency over the course of many generations. E) It is the conceptual link between irritability and adaptation. |
B
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3) 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 is possible. A) I and II B) I and III C) II and III D) I, II, and III |
B
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4) 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
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7) 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
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9) 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 |
A
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10) Theoretically, the production of sterile mules by interbreeding between female horses (mares) and male donkeys (jacks) 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
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15) What does the biological species concept use as the primary criterion for determining species boundaries?
A) geographic isolation B) niche differences C) gene flow D) morphological similarity E) molecular (DNA, RNA, protein) similarity |
C
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18) 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
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19) Among known plant species, which of these have been the two most commonly occurring phenomena that have led to the origin of new species?
1. allopatric speciation 2. sympatric speciation 3. sexual selection 4. polyploidy |
2 AND 4
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21) 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
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23) A hybrid zone is properly defined as
A) an area where two closely related species' 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
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24) 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
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25) 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
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28) 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. |
D
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29) 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
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30) 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. |
E
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31) 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. |
E
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32) 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. |
E
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1) 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 |
1 and 3
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3) 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. |
C
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4) 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 |
C
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5) Which of the following is a defining characteristic that all protobionts had in common?
A) the ability to synthesize enzymes B) a surrounding membrane or membrane-like structure C) RNA genes D) the ability to replicate RNA |
B
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6) 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. |
C
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7) 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. |
B
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9) 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 |
2 AND 5
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10) If the half-life of carbon-14 is about 5,730 years, then a fossil that has one-sixteenth the normal proportion of carbon-14 to carbon-12 should be about how many years old?
A) 1,400 B) 2,800 C) 11,200 D) 16,800 E) 22,900 |
E
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11) Which measurement(s) would help determine absolute dates by radiometric means?
A) the accumulation of the daughter isotope B) the loss of parent isotopes C) the loss of daughter isotopes D) Three of the responses above are correct. E) Two of the responses above are correct. |
E
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12) Approximately how far back in time does the fossil record extend?
A) 3.5 million years B) 5.0 million years C) 3.5 billion years D) 5.0 billion years |
C
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13) 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. |
C
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16) 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. |
E
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17) 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. |
E
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18) 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 |
C
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20) 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. |
C
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22) Which event is nearest in time to the end of the period known as snowball Earth?
A) oxygenation of Earth's seas and atmosphere B) evolution of mitochondria C) Cambrian explosion D) evolution of true multicellularity E) Permian extinction |
C
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26) 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. |
A
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27) The major evolutionary episode corresponding most closely in time with the formation of Pangaea was the
A) Cambrian explosion. B) Permian extinctions. C) Pleistocene ice ages. D) Cretaceous extinctions. |
B
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29) 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. |
C
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36) If one organ is an exaptation of another organ, then what must be true of these two organs?
A) They are both vestigial organs. B) They are both homologous organs. C) They are undergoing convergent evolution. D) They are found together in the same hybrid species. E) They have the same function. |
B
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58) Which of the following is the most likely explanation for the modern-day distribution of dicynodont fossils?
A) There had been two previous supercontinents that existed at different times long before the Permian period. B) The dicynodonts were evenly distributed throughout all of Pangaea. C) The dicynodonts were distributed more abundantly throughout Gondwanaland than throughout any other land mass. D) The dicynodonts were amphibious and able to swim long distances. E) The dicynodonts could survive for periods of months aboard "rafts" of vegetation, few of which made their way to the northern hemisphere. |
C
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71) Which factor most likely caused animals and plants in India to differ greatly from species in nearby southeast Asia?
A) The species have become separated by convergent evolution. B) The climates of the two regions are similar. C) India is in the process of separating from the rest of Asia. D) Life in India was wiped out by ancient volcanic eruptions. E) India was a separate continent until 45 million years ago. |
E
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74) A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped make possible the evolution of the tetrapod limb. This type of change is illustrative of
A) the influence of environment on development. B) paedomorphosis. C) a change in a developmental gene or its regulation that altered the spatial organization of body parts. D) heterochrony. E) gene duplication. |
C
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75) A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of
A) an evolutionary trend. B) exaptation. C) changes in Hox gene expression. D) paedomorphosis. E) adaptive radiation. |
B
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2) The various taxonomic levels (namely, genera, classes, etc.) of the hierarchical classification system differ from each other on the basis of
A) how widely the organisms assigned to each are distributed throughout the environment. B) their inclusiveness. C) the relative genome sizes of the organisms assigned to each. D) morphological characters that are applicable to all organisms. |
B
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3) If organisms A, B, and C belong to the same class but to different orders and if organisms D, E, and F belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?
A) A and B B) A and C C) B and D D) C and F E) D and F |
E
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4) Linnaeus was a "fixist" who believed that species remained fixed in the form in which they had been created. Linnaeus would have been uncomfortable with
A) classifying organisms using the morphospecies concept. B) the scientific discipline known as taxonomy. C) phylogenies. D) nested, ever-more inclusive categories of organisms. E) a hierarchical classification scheme. |
C
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6) Which individual would make the worst systematist? One who is uncomfortable with the
A) Linnaean system of classification. B) notion of hypothetical phylogenies. C) PhyloCode method of classification. D) notion of permanent polytomies. |
B
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8) If, someday, an archaean cell is discovered whose rRNA sequence is more similar to that of humans than the sequence of mouse rRNA is to that of humans, the best explanation for this apparent discrepancy would be
A) homology. B) homoplasy. C) common ancestry. D) retro-evolution by humans. E) coevolution of humans and that archaean. |
B
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9) The best classification system is that which most closely
A) unites organisms that possess similar morphologies. B) conforms to traditional, Linnaean taxonomic practices. C) reflects evolutionary history. D) reflects the basic separation of prokaryotes from eukaryotes. |
C
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10) Which of the following pairs are the best examples of homologous structures?
A) bones in the bat wing and bones in the human forelimb B) owl wing and hornet wing C) bat wing and bird wing D) eyelessness in the Australian mole and eyelessness in the North American mole |
A
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11) Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). Consequently, the morphological similarities of these two species are probably due to
A) inheritance of acquired characteristics. B) sexual selection. C) inheritance of shared derived characters. D) possession of analogous structures. E) possession of shared primitive characters. |
D
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12) The importance of computers and of computer software to modern cladistics is most closely linked to advances in
A) light microscopy. B) radiometric dating. C) fossil discovery techniques. D) Linnaean classification. E) molecular genetics. |
E
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13) Which mutation should least require realignment of homologous regions of a gene that is common to several related species?
A) three-base insertion B) one-base substitution C) four-base insertion D) one-base deletion E) three-base deletion |
B
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15) Which of the following is true of all horizontally oriented phylogenetic trees, where time advances to the right?
A) Each branch point represents a point in absolute time. B) Organisms represented at the base of such trees are descendants of those represented at higher levels. C) The fewer branch points that occur between two taxa, the more divergent their DNA sequences should be. D) 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. E) The more branch points there are, the fewer taxa are likely to be represented. |
D
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16) When using a cladistic approach to systematics, which of the following is considered most important for classification?
A) shared primitive characters B) analogous primitive characters C) shared derived characters D) the number of homoplasies E) overall phenotypic similarity |
C
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17) Cladograms (a type of phylogenetic tree) constructed from evidence from molecular systematics are based on similarities in
A) morphology. B) the pattern of embryological development. C) biochemical pathways. D) habitat and lifestyle choices. E) mutations to homologous genes. |
E
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21) Nucleic acid sequences that undergo few changes over the course of evolutionary time are said to be conserved. Conserved sequences of nucleic acids
A) are found in the most crucial portions of proteins. B) include all mitochondrial DNA. C) are abundant in ribosomes. D) are proportionately more common in eukaryotic introns than in eukaryotic exons. E) comprise a larger proportion of pre-mRNA (immature mRNA) than of mature mRNA. |
C
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22) Species that are not closely related and that do not share many anatomical similarities can still be placed together on the same phylogenetic tree by comparing their
A) plasmids. B) mitochondrial genomes. C) homologous genes that are poorly conserved. D) homologous genes that are highly conserved. |
D
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23) Which kind of DNA should provide the best molecular clock for determining the evolutionary relatedness of several species whose common ancestor became extinct billions of years ago?
A) that coding for ribosomal RNA B) intronic DNA belonging to a gene whose product performs a crucial function C) paralogous DNA that has lost its function (i.e., no longer codes for functional gene product) D) mitochondrial DNA E) exonic DNA that codes for a noncrucial part of a polypeptide |
A
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24) A phylogenetic tree constructed using sequence differences in mitochondrial DNA would be most valid for discerning the evolutionary relatedness of
A) archaeans and bacteria. B) fungi and animals. C) chimpanzees and humans. D) sharks and dolphins. E) mosses and ferns. |
C
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28) Paralogous genes that have lost the function of coding for any functional gene product are known as "pseudogenes." Which of these is a valid prediction regarding the fate of pseudogenes over evolutionary time?
A) They will be preserved by natural selection. B) They will be highly conserved. C) They will ultimately regain their original function. D) They will be transformed into orthologous genes. E) They will have relatively high mutation rates. |
E
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29) The most important feature that permits a gene to act as a molecular clock is
A) having a large number of base pairs. B) having a larger proportion of exonic DNA than of intronic DNA. C) having a reliable average rate of mutation. D) its recent origin by a gene-duplication event. E) its being acted upon by natural selection. |
C
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30) Neutral theory proposes that
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) DNA is less susceptible to mutation when it codes for amino acid sequences whose side groups (or R groups) have a neutral pH. D) DNA is less susceptible to mutation when it codes for amino acid sequences whose side groups (or R groups) have a neutral electrical charge. E) a significant proportion of mutations are not acted upon by natural selection. |
E
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31) When it acts upon a gene, which of the following processes consequently makes that gene an accurate molecular clock?
A) transcription B) directional natural selection C) mutation D) proofreading E) reverse transcription |
C
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32) Which of these would, if it had acted upon a gene, prevent this gene from acting as a reliable molecular clock?
A) neutral mutations B) genetic drift C) mutations within introns D) natural selection E) most substitution mutations involving an exonic codon's third position |
D
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51) If the early history of life on Earth is accurately depicted by Figure 26.4, then which statement is least in agreement with the hypothesis proposed by this tree?
A) The last universal common ancestor of all extant species is better described as a community of organisms, rather than an individual species. B) The origin of the three domains appears as a polytomy. C) Archaean genomes should contain genes that originated in bacteria, and vice versa. D) Eukaryotes are more closely related to archaeans than to bacteria. |
d
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52) Which of these processes can be included among those responsible for the horizontal components of Figure 26.4?
A) endosymbiosis B) mitosis C) binary fission D) point mutations E) S phase of the cell cycle |
A
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53) Which portion of Figure 26.4 may ultimately be better depicted as a "ring"?
A) the bacterial lineage B) the archaean lineage C) the eukaryotic lineage D) the trunk of the tree E) the part corresponding to the first living cell on Earth |
D
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A) The salamander lineage is a basal taxon.
B) Salamanders are a sister group to the group containing lizards, goats, and humans. C) Salamanders are as closely related to goats as to humans. D) Lizards are more closely related to salamanders than to humans. |
D
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2) Which of the following is (are) true for anabolic pathways?
A) They do not depend on enzymes. B) They are usually highly spontaneous chemical reactions. C) They consume energy to build up polymers from monomers. D) They release energy as they degrade polymers to monomers. E) They consume energy to decrease the entropy of the organism and its environment. |
c
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42) Where is ATP synthase located in the mitochondrion?
A) cytosol B) electron transport chain C) outer membrane D) inner membrane E) mitochondrial matrix |
D
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26) During cellular respiration, acetyl CoA accumulates in which location?
A) cytosol B) mitochondrial outer membrane C) mitochondrial inner membrane D) mitochondrial intermembrane space E) mitochondrial matrix |
E
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39) Which type of interaction stabilizes the α helix and the β pleated sheet structures of proteins?
A) hydrophobic interactions B) disulfide bonds C) ionic bonds D) hydrogen bonds E) peptide bonds |
D
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30) The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells?
A) rough ER B) smooth ER C) Golgi apparatus D) nuclear envelope E) transport vesicles |
B
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7) What is the chemical reaction mechanism by which cells make polymers from monomers?
A) phosphodiester linkages B) hydrolysis C) dehydration reactions D) ionic bonding of monomers E) the formation of disulfide bridges between monomers |
C
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7) According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids?
A) They can move laterally along the plane of the membrane. B) They frequently flip-flop from one side of the membrane to the other. C) They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane. D) They are free to depart from the membrane and dissolve in the surrounding solution. E) They have hydrophilic tails in the interior of the membrane. |
A
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10) The ATP made during glycolysis is generated by
A) substrate-level phosphorylation. B) electron transport. C) photophosphorylation. D) chemiosmosis. E) oxidation of NADH to NAD+. |
A
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27) Hydrolytic enzymes must be segregated and packaged to prevent general destruction of cellular components. Which of the following organelles contains these hydrolytic enzymes in animal cells?
A) chloroplast B) lysosome C) central vacuole D) peroxisome E) glyoxysome |
B
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46) How does a noncompetitive inhibitor decrease the rate of an enzyme reaction?
A) by binding at the active site of the enzyme B) by changing the shape of the enzyme's active site C) by changing the free energy change of the reaction D) by acting as a coenzyme for the reaction E) by decreasing the activation energy of the reaction |
B
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36) Which animal cell organelle contains enzymes that transfer hydrogen from various substrates to oxygen?
A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome |
E
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3) Which of the following is a statement of the first law of thermodynamics?
A) Energy cannot be created or destroyed. B) The entropy of the universe is decreasing. C) The entropy of the universe is constant. D) Kinetic energy is stored energy that results from the specific arrangement of matter. E) Energy cannot be transferred or transformed. |
A
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22) Which of the following statements is true for the class of biological molecules known as lipids?
A) They are insoluble in water. B) They are made from glycerol, fatty acids, and phosphate. C) They contain less energy than proteins and carbohydrates. D) They are made by dehydration reactions. E) They contain nitrogen. |
A
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46) Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this most probably mean?
A) Proton pumps must have evolved before any living organisms were present on Earth. B) Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life. C) The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism. D) Cells of each domain evolved proton pumps independently when oceans became more acidic. E) Proton pumps are necessary to all cell membranes. |
B
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30) There are 20 different amino acids. What makes one amino acid different from another?
A) different side chains (R groups) attached to a carboxyl carbon B) different side chains (R groups) attached to the amino groups C) different side chains (R groups) attached to an α carbon D) different structural and optical isomers E) different asymmetric carbons |
C
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64) Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through
A) plasmodesmata. B) intermediate filaments. C) tight junctions. D) desmosomes. E) gap junctions. |
E
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14) An animal cell lacking oligosaccharides on the external surface of its plasma membrane would likely be impaired in which function?
A) transporting ions against an electrochemical gradient B) cell-cell recognition C) maintaining fluidity of the phospholipid bilayer D) attaching to the cytoskeleton E) establishing the diffusion barrier to charged molecules |
B
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23) Why is ATP an important molecule in metabolism?
A) Its hydrolysis provides an input of free energy for exergonic reactions. B) It provides energy coupling between exergonic and endergonic reactions. C) Its terminal phosphate group contains a strong covalent bond that, when hydrolyzed, releases free energy. D) Its terminal phosphate bond has higher energy than the other two. E) It is one of the four building blocks for DNA synthesis. |
B
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1) Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?
A) catalysis B) metabolism C) anabolism D) dehydration E) catabolism |
E
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16) If radioactive deoxythymidine triphosphate (dTTP) is added to a culture of rapidly growing bacterial cells, where in the cell would you expect to find the greatest concentration of radioactivity?
A) nucleus B) cytoplasm C) endoplasmic reticulum D) nucleoid E) ribosomes |
D
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9) Where does glycolysis take place in eukaryotic cells?
A) mitochondrial matrix B) mitochondrial outer membrane C) mitochondrial inner membrane D) mitochondrial intermembrane space E) cytosol |
E
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9) All of the following are part of a prokaryotic cell except
A) DNA. B) a cell wall. C) a plasma membrane. D) ribosomes. E) an endoplasmic reticulum. |
E
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20) A chemical reaction that has a positive ΔG is correctly described as
A) endergonic. B) endothermic. C) enthalpic. D) spontaneous. E) exothermic. |
A
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65) If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence
A) 5'TAACGT3'. B) 5'TGCAAT3'. C) 5'UAACGU3'. D) 3'UAACGU5'. E) 5'UGCAAU3'. |
B
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17) In addition to ATP, what are the end products of glycolysis?
A) CO2 and H2O B) CO2 and pyruvate C) NADH and pyruvate D) CO2 and NADH E) H2O, FADH2, and citrate |
C
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23) Which structure is the site of the synthesis of proteins that may be exported from the cell?
A) rough ER B) lysosomes C) plasmodesmata D) Golgi vesicles E) free cytoplasmic ribosomes |
A
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18) The cell membranes of Antarctic ice fish might have which of the following adaptations?
A) very long chain fatty acids B) branched isoprenoid lipids C) a high percentage of polyunsaturated fatty acids D) a higher percentage of trans-fatty acids E) no cholesterol |
C
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11) The oxygen consumed during cellular respiration is involved directly in which process or event?
A) glycolysis B) accepting electrons at the end of the electron transport chain C) the citric acid cycle D) the oxidation of pyruvate to acetyl CoA E) the phosphorylation of ADP to form ATP |
B
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39) Increasing the substrate concentration in an enzymatic reaction could overcome which of the following?
A) denaturization of the enzyme B) allosteric inhibition C) competitive inhibition D) saturation of the enzyme activity E) insufficient cofactors |
C
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32) Where are the proteins of the electron transport chain located?
A) cytosol B) mitochondrial outer membrane C) mitochondrial inner membrane D) mitochondrial intermembrane space E) mitochondrial matrix |
C
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51) The difference between pinocytosis and receptor-mediated endocytosis is that
A) pinocytosis brings only water molecules into the cell, but receptor-mediated endocytosis brings in other molecules as well. B) pinocytosis increases the surface area of the plasma membrane whereas receptor-mediated endocytosis decreases the plasma membrane surface area. C) pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity. D) pinocytosis requires cellular energy, but receptor-mediated endocytosis does not. E) pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated |
C
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21) A cell with a predominance of free ribosomes is most likely
A) producing primarily proteins for secretion. B) producing primarily cytoplasmic proteins. C) constructing an extensive cell wall or extracellular matrix. D) digesting large food particles. E) enlarging its vacuole. |
B
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66) What is the structural feature that allows DNA to replicate?
A) sugar-phosphate backbone B) complementary pairing of the nitrogenous bases C) disulfide bonding (bridging) of the two helixes D) twisting of the molecule to form an α helix E) three-component structure of the nucleotides |
B
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30) Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a 0.15 M salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are
A) hypotonic to both fresh water and the salt solution. B) hypertonic to both fresh water and the salt solution. C) hypertonic to fresh water but hypotonic to the salt solution. D) hypotonic to fresh water but hypertonic to the salt solution. E) isotonic with fresh water but hypotonic to the salt solution. |
C
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29) Water passes quickly through cell membranes because
A) the bilayer is hydrophilic. B) it moves through hydrophobic channels. C) water movement is tied to ATP hydrolysis. D) it is a small, polar, charged molecule. E) it moves through aquaporins in the membrane. |
E
|
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6) Which of the following is not a polymer?
A) glucose B) starch C) cellulose D) chitin E) DNA |
A
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14) The mathematical expression for the change in free energy of a system is ΔG =ΔH - TΔS. Which of the following is (are) correct?
A) ΔS is the change in enthalpy, a measure of randomness. B) ΔH is the change in entropy, the energy available to do work. C) ΔG is the change in free energy. D) T is the temperature in degrees Celsius. |
C
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12) Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent?
A) electron transport B) glycolysis C) the citric acid cycle D) oxidative phosphorylation E) chemiosmosis |
B
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22) Which type of organelle or structure is primarily involved in the synthesis of oils, phospholipids, and steroids?
A) ribosome B) lysosome C) smooth endoplasmic reticulum D) mitochondrion E) contractile vacuole |
C
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|
49) White blood cells engulf bacteria through what process?
A) exocytosis B) phagocytosis C) pinocytosis D) osmosis E) receptor-mediated exocytosis |
B
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25) Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate?
A) lactate B) glyceraldehydes-3-phosphate C) oxaloacetate D) acetyl CoA E) citrate |
D
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6) The presence of cholesterol in the plasma membranes of some animals
A) enables the membrane to stay fluid more easily when cell temperature drops. B) enables the animal to remove hydrogen atoms from saturated phospholipids. C) enables the animal to add hydrogen atoms to unsaturated phospholipids. D) makes the membrane less flexible, allowing it to sustain greater pressure from within the cell. E) makes the animal more susceptible to circulatory disorders. |
A
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11) The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?
A) C18H36O18 B) C18H32O16 C) C6H10O5 D) C18H10O15 E) C3H6O3 |
B
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47) Movement of vesicles within the cell depends on what cellular structures?
A) microtubules and motor proteins B) actin filaments and microtubules C) actin filaments and ribosomes D) centrioles and motor proteins E) actin filaments and motor proteins |
A
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31) Which of the following produces and modifies polysaccharides that will be secreted?
A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome |
D
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33) In cellular respiration, the energy for most ATP synthesis is supplied by
A) high energy phosphate bonds in organic molecules. B) a proton gradient across a membrane. C) converting oxygen to ATP. D) transferring electrons from organic molecules to pyruvate. E) generating carbon dioxide and oxygen in the electron transport chain. |
B
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5) Which of these classes of biological molecules consist of both small molecules and macromolecular polymers?
A) lipids B) carbohydrates C) proteins D) nucleic acids E) lipids, carbohydrates, proteins, and nucleic acids all consist of only macromolecular polymers |
B
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44) Independent assortment of chromosomes is a result of
A) the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I. B) the random nature of the fertilization of ova by sperm. C) the random distribution of the sister chromatids to the two daughter cells during anaphase II. D) the relatively small degree of homology shared by the X and Y chromosomes. E) the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I, the random nature of the fertilization of ova by sperm, the random distribution of the sister chromatids to the two daughter cells during anaphase II, and the relatively small degree of homology shared by the X and Y chromosomes. |
A
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4) Where does the Calvin cycle take place?
A) stroma of the chloroplast B) thylakoid membrane C) cytoplasm surrounding the chloroplast D) interior of the thylakoid (thylakoid space) E) outer membrane of the chloroplast |
A
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34) A tetrad includes which of the following sets of DNA strands?
A) two single-stranded chromosomes that have synapsed B) two sets of sister chromatids that have synapsed C) four sets of sister chromatids D) four sets of unique chromosomes E) eight sets of sister chromatids |
B
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25) Which of the following is an example of polygenic inheritance?
A) pink flowers in snapdragons B) the ABO blood group in humans C) Huntington's disease in humans D) white and purple flower color in peas E) skin pigmentation in humans |
E
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41) Which of the following is known as a Philadelphia chromosome?
A) a human chromosome 22 that has had a specific translocation B) a human chromosome 9 that is found only in one type of cancer C) an animal chromosome found primarily in the mid-Atlantic area of the United States D) an imprinted chromosome that always comes from the mother E) a chromosome found not in the nucleus but in mitochondria |
A
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13) Sex determination in mammals is due to the SRY region of the Y chromosome. An abnormality of this region could allow which of the following to have a male phenotype?
A) Turner syndrome, 45, X B) translocation of SRY to an autosome of a 46, XX individual C) a person with an extra X chromosome D) a person with one normal and one shortened (deleted) X E) Down syndrome, 46, XX |
B
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5) In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary?
A) autotrophs and heterotrophs B) producers and primary consumers C) photosynthesizers D) autotrophs E) green plants |
D
|
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3) If there are 20 chromatids in a cell, how many centromeres are there?
A) 10 B) 20 C) 30 D) 40 E) 80 |
A
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40) At puberty, an adolescent female body changes in both structure and function of several organ systems, primarily under the influence of changing concentrations of estrogens and other steroid hormones. How can one hormone, such as estrogen, mediate so many effects?
A) Estrogen is produced in very large concentration and therefore diffuses widely. B) Estrogen has specific receptors inside several cell types, but each cell responds in the same way to its binding. C) Estrogen is kept away from the surface of any cells not able to bind it at the surface. D) Estrogen binds to specific receptors inside many kinds of cells, each of which have different responses to its binding. E) The subcomponents of estrogen, when metabolized, can influence cell response. |
D
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42) How does the sexual life cycle increase the genetic variation in a species?
A) by allowing crossing over B) by allowing fertilization C) by increasing gene stability D) by conserving chromosomal gene order E) by decreasing mutation frequency |
A
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6) Males are more often affected by sex-linked traits than females because
A) male hormones such as testosterone often alter the effects of mutations on the X chromosome. B) female hormones such as estrogen often compensate for the effects of mutations on the X chromosome. C) X chromosomes in males generally have more mutations than X chromosomes in females. D) males are hemizygous for the X chromosome. E) mutations on the Y chromosome often worsen the effects of X-linked mutations. |
D
|
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|
26) Adenylyl cyclase has the opposite effect of which of the following?
A) protein kinase B) protein phosphatase C) phosphodiesterase D) phosphorylase E) GTPase |
C
|
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|
25) An inhibitor of phosphodiesterase activity would have which of the following effects?
A) block the response of epinephrine B) decrease the amount of cAMP in the cytoplasm C) block the activation of G proteins in response to epinephrine binding to its receptor D) prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm E) block the activation of protein kinase A |
D
|
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|
35) The MPF protein complex turns itself off by
A) activating a process that destroys cyclin components. B) activating an enzyme that stimulates cyclin. C) binding to chromatin. D) exiting the cell. E) activating the anaphase-promoting complex. |
A
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7) The human X and Y chromosomes
A) are both present in every somatic cell of males and females alike. B) are of approximately equal size and number of genes. C) are almost entirely homologous, despite their different names. D) include genes that determine an individual's sex. E) include only genes that govern sex determination. |
D
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|
27) Which of the following provides an example of epistasis?
A) Recessive genotypes for each of two genes (aabb) results in an albino corn snake. B) The allele b17 produces a dominant phenotype, although b1 through b16 do not. C) In rabbits and many other mammals, one genotype (cc) prevents any fur color from developing. D) In Drosophila (fruit flies), white eyes can be due to an X-linked gene or to a combination of other genes. E) In cacti, there are several genes for the type of spines. |
C
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26) Which of the following happens at the conclusion of meiosis I?
A) Homologous chromosomes are separated. B) The chromosome number per cell is conserved. C) Sister chromatids are separated. D) Four daughter cells are formed. E) The sperm cells elongate to form a head and a tail end. |
A
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|
77) Which of the following does not occur during mitosis?
A) condensation of the chromosomes B) replication of the DNA C) separation of sister chromatids D) spindle formation E) separation of the spindle poles |
B
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32) Which of the following triggers the cell's passage past the G2 checkpoint into mitosis?
A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk |
B
|
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37) The reactions that produce molecular oxygen (O2) take place in
A) the light reactions alone. B) the Calvin cycle alone. C) both the light reactions and the Calvin cycle. D) neither the light reactions nor the Calvin cycle. E) the chloroplast, but are not part of photosynthesis. |
A
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11) Mendel accounted for the observation that traits which had disappeared in the F1 generation reappeared in the F2 generation by proposing that
A) new mutations were frequently generated in the F2 progeny, "reinventing" traits that had been lost in the F1. B) the mechanism controlling the appearance of traits was different between the F1 and the F2 plants. C) traits can be dominant or recessive, and the recessive traits were obscured by the dominant ones in the F1. D) the traits were lost in the F1 due to dominance of the parental traits. E) members of the F1 generation had only one allele for each trait, but members of the F2 had two alleles for each trait. |
C
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|
66) Consider this pathway: epinephrine → G protein-coupled receptor → G protein → adenylyl cyclase → cAMP. Identify the second messenger.
A) cAMP B) G protein C) GTP D) adenylyl cyclase E) G protein-coupled receptor |
A
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|
31) Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active?
A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk |
E
|
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|
2) The human genome is minimally contained in which of the following?
A) every human cell B) each human chromosome C) the entire DNA of a single human D) the entire human population E) each human gene |
A
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41) What is the primary function of the Calvin cycle?
A) use ATP to release carbon dioxide B) use NADPH to release carbon dioxide C) split water and release oxygen D) transport RuBP out of the chloroplast E) synthesize simple sugars from carbon dioxide |
E
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39) A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following?
A) lower cytoplasmic levels of cAMP B) an increase in receptor tyrosine kinase activity C) a decrease in transcriptional activity of certain genes D) an increase in cytosolic calcium concentration E) a decrease in G protein activity |
C
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44) Why has C. elegans proven to be a useful model for understanding apoptosis?
A) The animal has as many genes as complex organisms, but finding those responsible is easier than in a more complex organism. B) The nematode undergoes a fixed and easy-to-visualize number of apoptotic events during its normal development. C) This plant has a long-studied aging mechanism that has made understanding its death just a last stage. D) While the organism ages, its cells die progressively until the whole organism is dead. E) All of its genes are constantly being expressed so all of its proteins are available from each cell. |
B
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1) When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. What was the explanation for this result?
A) The gene involved is on the Y chromosome. B) The gene involved is on the X chromosome. C) The gene involved is on an autosome, but only in males. D) Other male-specific factors influence eye color in flies. E) Other female-specific factors influence eye color in flies. |
B
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34) Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in concentration during the cell cycle, are called
A) ATPases. B) kinetochores. C) kinases. D) proton pumps. E) cyclins. |
E
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17) Which of the following statements is true of linkage?
A) The closer two genes are on a chromosome, the lower the probability that a crossover will occur between them. B) The observed frequency of recombination of two genes that are far apart from each other has a maximum value of 100%. C) All of the traits that Mendel studied–seed color, pod shape, flower color, and others–are due to genes linked on the same chromosome. D) Linked genes are found on different chromosomes. E) Crossing over occurs during prophase II of meiosis. |
A
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73) Marfan syndrome in humans is caused by an abnormality of the connective tissue protein fibrillin. Patients are usually very tall and thin, with long spindly fingers, curvature of the spine, sometimes weakened arterial walls, and sometimes ocular problems, such as lens dislocation. Which of the following would you conclude about Marfan syndrome from this information?
A) It is recessive. B) It is dominant. C) It has a late age of onset (> 60). D) It is pleiotropic. E) It is epistatic. |
D
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46) When homologous chromosomes crossover, what occurs?
A) Two chromatids get tangled, resulting in one re-sequencing its DNA. B) Two sister chromatids exchange identical pieces of DNA. C) Specific proteins break the two strands and re-join them with their homologs. D) Each of the four DNA strands of a tetrad is broken and the pieces are mixed. E) Maternal alleles are "corrected" to be like paternal alleles and vice versa. |
C
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62) Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because
A) they are species specific. B) they always lead to the same cellular response. C) they amplify the original signal manyfold. D) they counter the harmful effects of phosphatases. E) the number of molecules used is small and fixed. |
C
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30) Which of the following occurs in meiosis but not in mitosis?
A) chromosome replication B) synapsis of chromosomes C) production of daughter cells D) alignment of chromosomes at the equator E) condensation of chromatin |
B
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20) What is the reason that linked genes are inherited together?
A) They are located close together on the same chromosome. B) The number of genes in a cell is greater than the number of chromosomes. C) Chromosomes are unbreakable. D) Alleles are paired together during meiosis. E) Genes align that way during metaphase I of meiosis. |
A
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14) One of the major categories of receptors in the plasma membrane reacts by forming dimers, adding phosphate groups, and then activating relay proteins. Which type does this?
A) G protein-coupled receptors B) ligand-gated ion channels C) steroid receptors D) receptor tyrosine kinases |
D
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35) What is the source of the extra chromosome 21 in an individual with Down syndrome?
A) nondisjunction in the mother only B) nondisjunction in the father only C) duplication of the chromosome D) nondisjunction or translocation in either parent E) It is impossible to detect with current technology. |
D
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4) How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE?
A) 4 B) 8 C) 16 D) 32 E) 64 |
B
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9) In an analysis of the nucleotide composition of DNA, which of the following will be found?
A) A = C B) A = G and C = T C) A + C = G + T D) G + C = T + A |
C
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21) Alternative RNA splicing
A) is a mechanism for increasing the rate of transcription. B) can allow the production of proteins of different sizes from a single mRNA. C) can allow the production of similar proteins from different RNAs. D) increases the rate of transcription. E) is due to the presence or absence of particular snRNPs. |
B
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34) In 1997, Dolly the sheep was cloned. Which of the following processes was used?
A) use of mitochondrial DNA from adult female cells of another ewe B) replication and dedifferentiation of adult stem cells from sheep bone marrow C) separation of an early stage sheep blastula into separate cells, one of which was incubated in a surrogate ewe D) fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate E) isolation of stem cells from a lamb embryo and production of a zygote equivalent |
D
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91) Muscle cells differ from nerve cells mainly because they
A) express different genes. B) contain different genes. C) use different genetic codes. D) have unique ribosomes. E) have different chromosomes. |
A
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16) Eukaryotic telomeres replicate differently than the rest of the chromosome. This is a consequence of which of the following?
A) the evolution of telomerase enzyme B) DNA polymerase that cannot replicate the leading strand template to its 5' end C) gaps left at the 5' end of the lagging strand D) gaps left at the 3' end of the lagging strand because of the need for a primer E) the "no ends" of a circular chromosome |
C
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41) In recent times, it has been shown that adult cells can be induced to become pluripotent stem cells (iPS). In order to make this conversion, what has been done to the adult cells?
A) A retrovirus is used to introduce four specific regulatory genes. B) The adult stem cells must be fused with embryonic cells. C) Cytoplasm from embryonic cells is injected into the adult cells. D) An adenovirus vector is used to transfer embryonic gene products into adult cells. E) The nucleus of an embryonic cell is used to replace the nucleus of an adult cell. |
a
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21) What characteristic of short tandem repeat DNA makes it useful for DNA fingerprinting?
A) The number of repeats varies widely from person to person or animal to animal. B) The sequence of DNA that is repeated varies significantly from individual to individual. C) The sequence variation is acted upon differently by natural selection in different environments. D) Every racial and ethnic group has inherited different short tandem repeats. |
a
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18) What is a ribozyme?
A) an enzyme that uses RNA as a substrate B) an RNA with enzymatic activity C) an enzyme that catalyzes the association between the large and small ribosomal subunits D) an enzyme that synthesizes RNA as part of the transcription process E) an enzyme that synthesizes RNA primers during DNA replication |
B
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9) Why do RNA viruses appear to have higher rates of mutation?
A) RNA nucleotides are more unstable than DNA nucleotides. B) Replication of their genomes does not involve proofreading. C) RNA viruses replicate faster. D) RNA viruses can incorporate a variety of nonstandard bases. E) RNA viruses are more sensitive to mutagens. |
B
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3) The host range of a virus is determined by
A) the enzymes carried by the virus. B) whether its nucleic acid is DNA or RNA. C) the proteins in the host's cytoplasm. D) the enzymes produced by the virus before it infects the cell. E) the proteins on its surface and that of the host. |
E
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41) When the function of the newly made polypeptide is to be secreted from the cell where it has been made, what must occur?
A) It must be translated by a ribosome that remains free of attachment to the ER. B) Its signal sequence must target it to the ER, from which it goes to the Golgi. C) It has a signal sequence that must be cleaved off before it can enter the ER. D) It has a signal sequence that targets it to the cell's plasma membrane where it causes exocytosis. E) Its signal sequence causes it to be encased in a vesicle as soon as it is translated. |
B
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4) Which of the following most correctly describes a shotgun technique for sequencing a genome?
A) genetic mapping followed immediately by sequencing B) physical mapping followed immediately by sequencing C) cloning large genome fragments into very large vectors such as YACs, followed by sequencing D) cloning several sizes of fragments into various size vectors, ordering the clones, and then sequencing them E) cloning the whole genome directly, from one end to the other |
D
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47) Mutations in which of the following genes lead to transformations in the identity of entire body parts?
A) morphogens B) segmentation genes C) egg-polarity genes D) homeotic genes E) inducers |
D
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19) The reason for using Taq polymerase for PCR is that
A) it is heat stable and can withstand the temperature changes of the cycler. B) only minute amounts are needed for each cycle of PCR. C) it binds more readily than other polymerases to primer. D) it has regions that are complementary to primers. E) All of these are correct. |
A
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8) What is bioinformatics?
A) a technique using 3-D images of genes in order to predict how and when they will be expressed B) a method that uses very large national and international databases to access and work with sequence information C) a software program available from NIH to design genes D) a series of search programs that allow a student to identify who in the world is trying to sequence a given species E) a procedure that uses software to order DNA sequences in a variety of comparable ways |
B
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33) There are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. This is best explained by the fact that
A) some tRNAs have anticodons that recognize four or more different codons. B) the rules for base pairing between the third base of a codon and tRNA are flexible. C) many codons are never used, so the tRNAs that recognize them are dispensable. D) the DNA codes for all 61 tRNAs but some are then destroyed. E) competitive exclusion forces some tRNAs to be destroyed by nucleases. |
B
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41) In animals, embryonic stem cells differ from adult stem cells in that
A) embryonic stem cells are totipotent, and adult stem cells are pluripotent. B) embryonic stem cells are pluripotent, and adult stem cells are totipotent. C) embryonic stem cells have more genes than adult stem cells. D) embryonic stem cells have fewer genes than adult stem cells. E) embryonic stem cells are localized to specific sites within the embryo, whereas adult stem cells are spread throughout the body. |
A
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14) Which of the following can be effective in preventing the onset of viral infection in humans?
A) taking vitamins B) getting vaccinated C) taking antibiotics D) applying antiseptics E) taking nucleoside analogs that inhibit transcription |
B
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45) To cause a human pandemic, the H5N1 avian flu virus would have to
A) spread to primates such as chimpanzees. B) develop into a virus with a different host range. C) become capable of human-to-human transmission. D) arise independently in chickens in North and South America. E) become much more pathogenic. |
C
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40) One of the characteristics of retrotransposons is that
A) they code for an enzyme that synthesizes DNA using an RNA template. B) they are found only in animal cells. C) they generally move by a cut-and-paste mechanism. D) they contribute a significant portion of the genetic variability seen within a population of gametes. E) their amplification is dependent on a retrovirus. |
A
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48) Which of the following DNA mutations is the most likely to be damaging to the protein it specifies?
A) a base-pair deletion B) a codon substitution C) a substitution in the last base of a codon D) a codon deletion E) a point mutation |
A
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18) What are prions?
A) mobile segments of DNA B) tiny molecules of RNA that infect plants C) viral DNA that has had to attach itself to the host genome D) misfolded versions of normal brain protein E) viruses that invade bacteria |
D
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9) What is proteomics?
A) the linkage of each gene to a particular protein B) the study of the full protein set encoded by a genome C) the totality of the functional possibilities of a single protein D) the study of how amino acids are ordered in a protein E) the study of how a single gene activates many proteins |
B
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11) What is meant by the description "antiparallel" regarding the strands that make up DNA?
A) The twisting nature of DNA creates nonparallel strands. B) The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand. C) Base pairings create unequal spacing between the two DNA strands. D) One strand is positively charged and the other is negatively charged. E) One strand contains only purines and the other contains only pyrimidines. |
B
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3) How is a physical map of the genome of an organism achieved?
A) using recombination frequency B) using very high-powered microscopy C) using restriction enzyme cutting sites D) using sequencing of nucleotides E) using DNA fingerprinting via electrophoresis |
C
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22) Which of the following is the most probable fate of a newly emerging virus that causes high mortality in its host?
A) It is able to spread to a large number of new hosts quickly because the new hosts have no immunological memory of them. B) The new virus replicates quickly and undergoes rapid adaptation to a series of divergent hosts. C) A change in environmental conditions such as weather patterns quickly forces the new virus to invade new areas. D) Sporadic outbreaks will be followed almost immediately by a widespread pandemic. E) The newly emerging virus will die out rather quickly or will mutate to be far less lethal. |
E
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27) What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?
A) It synthesizes RNA nucleotides to make a primer. B) It catalyzes the lengthening of telomeres. C) It joins Okazaki fragments together. D) It unwinds the parental double helix. E) It stabilizes the unwound parental DNA. |
C
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1) The role of a metabolite that controls a repressible operon is to
A) bind to the promoter region and decrease the affinity of RNA polymerase for the promoter. B) bind to the operator region and block the attachment of RNA polymerase to the promoter. C) increase the production of inactive repressor proteins. D) bind to the repressor protein and inactivate it. E) bind to the repressor protein and activate it. |
E
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1) In his transformation experiments, what did Griffith observe?
A) Mutant mice were resistant to bacterial infections. B) Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form. C) Mixing a heat-killed nonpathogenic strain of bacteria with a living pathogenic strain makes the pathogenic strain nonpathogenic. D) Infecting mice with nonpathogenic strains of bacteria makes them resistant to pathogenic strains. E) Mice infected with a pathogenic strain of bacteria can spread the infection to other mice. |
B
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3) Which of the following is a protein produced by a regulatory gene?
A) operon B) inducer C) promoter D) repressor E) corepressor |
D
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8) It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in which of the following?
A) sequence of bases B) phosphate-sugar backbones C) complementary pairing of bases D) side groups of nitrogenous bases E) different five-carbon sugars |
A
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52) Which of the following statements describes proto-oncogenes?
A) Their normal function is to suppress tumor growth. B) They are introduced to a cell initially by retroviruses. C) They are produced by somatic mutations induced by carcinogenic substances. D) They can code for proteins associated with cell growth. E) They are underexpressed in cancer cells. |
D
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24) DNA microarrays have made a huge impact on genomic studies because they
A) can be used to eliminate the function of any gene in the genome. B) can be used to introduce entire genomes into bacterial cells. C) allow the expression of many or even all of the genes in the genome to be compared at once. D) allow physical maps of the genome to be assembled in a very short time. E) dramatically enhance the efficiency of restriction enzymes. |
C
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27) When does exon shuffling occur?
A) during splicing of DNA B) during mitotic recombination C) as an alternative splicing pattern in post-transcriptional processing D) as an alternative cleavage or modification post-translationally E) as the result of faulty DNA repair |
C
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9) Which of the following best describes the complete sequence of steps occurring during every cycle of PCR?
1. The primers hybridize to the target DNA. 2. The mixture is heated to a high temperature to denature the double-stranded target DNA. 3. Fresh DNA polymerase is added. 4. DNA polymerase extends the primers to make a copy of the target DNA. A) 2, 1, 4 B) 1, 3, 2, 4 C) 3, 4, 1, 2 D) 3, 4, 2 E) 2, 3, 4 |
A
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7) Which of the following is characteristic of the lytic cycle?
A) Many bacterial cells containing viral DNA are produced. B) Viral DNA is incorporated into the host genome. C) The viral genome replicates without destroying the host. D) A large number of phages are released at a time. E) The virus-host relationship usually lasts for generations. |
D
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17) Pax-6 is a gene that is involved in eye formation in many invertebrates, such as Drosophila. Pax-6 is found as well in vertebrates. A Pax-6 gene from a mouse can be expressed in a fly and the protein (PAX-6) leads to a compound fly eye. This information suggests which of the following?
A) Pax-6 genes are identical in nucleotide sequence. B) PAX-6 proteins have identical amino acid sequences. C) Pax-6 is highly conserved and shows shared evolutionary ancestry. D) PAX-6 proteins are different for formation of different kinds of eyes. E) PAX-6 from a mouse can function in a fly, but a fly's Pax-6 gene cannot function in a mouse. |
C
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14) The major advantage of using artificial chromosomes such as YACs and BACs for cloning genes is that
A) plasmids are unable to replicate in cells. B) only one copy of a plasmid can be present in any given cell, whereas many copies of a YAC or BAC can coexist in a single cell. C) YACs and BACs can carry much larger DNA fragments than ordinary plasmids can. D) YACs and BACs can be used to express proteins encoded by inserted genes, but plasmids cannot. E) All of these are correct. |
C
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30) The phenomenon in which RNA molecules in a cell are destroyed if they have a sequence complementary to an introduced double-stranded RNA is called
A) RNA interference. B) RNA obstruction. C) RNA blocking. D) RNA targeting. E) RNA disposal. |
A
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23) A multigene family is composed of
A) multiple genes whose products must be coordinately expressed. B) genes whose sequences are very similar and that probably arose by duplication. C) the many tandem repeats such as those found in centromeres and telomeres. D) a gene whose exons can be spliced in a number of different ways. E) a highly conserved gene found in a number of different species. |
B
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35) Which of the following describes the function of an enzyme known as Dicer?
A) It degrades single-stranded DNA. B) It degrades single-stranded mRNA. C) It degrades mRNA with no poly-A tail. D) It trims small double-stranded RNAs into molecules that can block translation. E) It chops up single-stranded DNAs from infecting viruses. |
D
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26) What is the function of topoisomerase?
A) relieving strain in the DNA ahead of the replication fork B) elongating new DNA at a replication fork by adding nucleotides to the existing chain C) adding methyl groups to bases of DNA D) unwinding of the double helix E) stabilizing single-stranded DNA at the replication fork |
A
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12) Which viruses have single-stranded RNA that acts as a template for DNA synthesis?
A) lytic phages B) proviruses C) viroids D) bacteriophages E) retroviruses |
E
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