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C |
Which statement shows population thinking? ANSWER: a. All species can be organized into a sequence of increasing complexity. b. Species do not change over time. c. Variation among individuals in a species is real and important. d. A single perfect specimen can represent a species. |
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c |
Which of the following statements is correct? a. Fossils from rocks under other rocks are younger than the fossils found above them. b. Most fossils formed during a few catastrophic events. c. Fossils form in sedimentary rocks. d. Fossils form only from the hard parts of extinct organisms. |
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c |
Why does the pattern of resemblance between the fossil record and the living species in a geographic area support the theory of evolution by natural selection? a. It provides evidence of the law of succession. b. It provides evidence that species become more complex over time. c. It provides evidence that species change over time. d. It provides evidence of population thinking. |
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a |
Which statement about vestigial traits is correct? a. Vestigial traits are similar to functional traits in closely related species. b. Humans lack vestigial traits. c. Vestigial traits cannot be explained by the theory of evolution by natural selection. d. Vestigial traits improve the biological fitness of individuals. |
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a |
Why do related species share homologous traits? ANSWER: a. Related species have inherited homologous traits from a common ancestor. b. Related species are adapted to similar environments. c. Homologous traits are the products of divergent evolution. d. Related species share key similarities in development. |
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a |
Which is an example of a structural homology? ANSWER: a. the similarity in number and arrangement of bones in vertebrate forelimbs b. the common genetic code shared by all organisms c. the same group of embryonic cells, which forms the adult jaw of a perch and a dog d. the post-anal tail formed during vertebrate development |
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a |
How is biological fitness measured? ANSWER: a. Biological fitness measures the relative reproductive success of an individual relative to others in the population. b. Biological fitness measures the longevity of an individual. c. Biological fitness measures the overall health of an individual. d. Biological fitness measures the number of offspring produced by an individual. |
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a |
Which statement is correct? ANSWER: a. Only populations can evolve. b. Natural selection acts on populations, not individuals. c. Evolutionary change results from specific mutations. d. Natural selection can change an individual’s allele frequencies. |
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b |
Why did the 1977 drought on Daphne Major lead to evolutionary change in the medium ground finch population? ANSWER: a. Daphne Major typically receives six times more rain than the amount that fell during 1977. b. Medium ground finches with large and deep beaks had high biological fitness during the drought. c. The drought was a particularly severe environmental perturbation. d. There was not enough food to support the medium ground finch population. |
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d |
Which statement about adaptation is correct? ANSWER: a. Better-adapted organisms are more complex than poorly adapted organisms. b. Adaptations arise because they are needed in particular environments. c. Higher organisms are better adapted than lower organisms. d. The adaptive value of a trait varies as the environment changes. |
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a. |
Which evolutionary mechanism results in adaptation? ANSWER: natural selection genetic drift gene flow mutation |
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b |
Which assumption must be correct for a specific gene in a population that is in Hardy-Weinberg equilibrium? ANSWER: Selection must favor one form of the gene. No genetic drift can affect allele frequencies for the gene. Mating must be nonrandom with respect to the gene. Immigration must equal emigration. |
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d |
If a population is NOT in Hardy-Weinberg equilibrium for a specific gene, which of the following can be said with certainty? ANSWER: New forms of the gene have entered the population due to immigration. Individuals with one form of the gene have greater mating success. Selection is acting on this gene. At least one mechanism that alters allele frequencies is acting on this gene. |
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c |
Which statement about balancing selection is correct? ANSWER: When balancing selection occurs, all genotypes have equal or balanced biological fitness. When balancing selection occurs, certain alleles are favored when they are common, but not when they are rare. When balancing selection occurs, no single allele has a distinct advantage and increases in frequency. When balancing selection occurs, homozygous dominant and homozygous recessive individuals have equal or balanced biological fitness. |
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c |
How do stabilizing and disruptive selection differ? ANSWER: With stabilizing selection, the average phenotype for a trait does not change. With disruptive selection, the average phenotype for a trait changes. Stabilizing selection produces adaptation. Disruptive selection is non-adaptive. Stabilizing selection reduces the amount of variation in a trait. Disruptive selection increases the amount of variation in a trait. With stabilizing selection, extreme individuals have high biological fitness. With disruptive selection, extreme individuals have low biological fitness. |
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d |
Which form of natural selection is most likely to play a role in speciation? ANSWER: Natural selection does not lead to speciation. directional selection stabilizing selection disruptive selection |
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b |
Which statement about genetic drift is correct? ANSWER: Genetic drift becomes increasingly important with increasing population size. The direction of evolutionary change due to genetic drift is random. Genetic drift increases adaptation of individuals to their environment. Genetic drift results from migration of new individuals into a population. |
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d |
What term is defined as the change in allele frequencies that occurs when a new population is established? ANSWER: gene flow random migration directional selection founder effect |
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a |
Which evolutionary mechanism increases genetic variation in a population? ANSWER: mutation founder effect genetic drift genetic bottleneck |
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b |
Which statement about inbreeding is correct? ANSWER: Offspring produced by inbreeding have high biological fitness. Inbreeding increases the rate of purifying selection. Inbreeding changes allele frequencies in a population. Inbreeding increases random mating. |
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c |
Which mechanism causes postzygotic reproductive isolation? ANSWER: mechanical isolation habitat isolation hybrid sterility temporal isolation |
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a |
Which species concept would be most useful to a team of biologists conducting a biodiversity survey? ANSWER: the morphospecies concept the phylogenetic species concept the biological species concept All species concepts would be equally useful. |
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b |
Which statement is correct? ANSWER: A monophyletic group may include an ancestral population and some, but not all, of its descendants. A monophyletic group consists of an ancestral population, all of its descendants, and only those descendants. A monophyletic group consists of all of the descendants of an ancestral population. A monophyletic group is a theoretical idea that does not exist in the real world. |
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b |
Which of the following situations describes vicariance? ANSWER: A small group of finches is blown from the mainland to a recently formed volcanic island. The Grand Canyon forms, separating two populations of squirrels on the North and South rims. Six moose are transported from New Brunswick to Newfoundland, where they establish a large population. American bullfrogs expand their range into British Columbia. |
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a |
Which is the first step in allopatric speciation? ANSWER: physical isolation of two populations differential natural selection in different environments loss of genetic variation due to genetic drift genetic divergence due to mutation |
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d |
How do autopolyploidy and allopolyploidy differ? ANSWER: Autopolyploidy is sympatric, whereas allopolyploidy is allopatric. Only autopolyploidy involves doubling of chromosome sets. Autopolyploidy is a mechanism of speciation in plants, whereas allopolyploidy is a mechanism of speciation in animals. The chromosomes of an autopolyploid individual come from the same species, whereas an allopolyploid individual has sets of chromosomes from different species. |
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d |
Which statement about polyploidy is correct? ANSWER: Polyploid and diploid populations hybridize readily. Triploid individuals can never reproduce successfully. Speciation by polyploidy is unknown in plants. Speciation by polyploidy may be almost instantaneous. |
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d |
Which description of reinforcement is correct? ANSWER: Reinforcement leads to development of a hybrid zone. Reinforcement is the genetic divergence of populations in different environments. Reinforcement is the loss of genetic differences between two populations due to gene flow. Reinforcement is natural selection against interbreeding and production of hybrid offspring. |
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c |
What occurs in a hybrid zone? ANSWER: disruptive selection reinforcement interbreeding extinction |
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c |
How did the sunflower species Helianthus anomalus originate? ANSWER: disruptive selection autopolyploidy hybridization allopolyploidy |
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d |
Which structures are homologous? ANSWER: plant leaf and algal blade There are no homologous plant structures. plant leaf and plant root oak leaf and maple leaf |
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d |
What is a fossil? ANSWER: A fossil is an extinct organism. A fossil is a preserved hard part of an organism, such as shell or bone. A fossil is an organism that has turned to stone. A fossil is physical evidence of an organism that lived in the past. |
|
a |
Which statement about fossilization is correct? ANSWER: Rare, local, or ephemeral species leave a poor fossil record. Organisms that live aboveground in dry areas are most likely to fossilize. Only hard parts of organisms can form fossils. Recent fossils are more common than ancient fossils because biodiversity has increased over evolutionary time. |
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c |
Which sequence of eons, from oldest to youngest, is correct? ANSWER: Phanerozoic, Proterozoic, Archaean, Hadean Archaean, Hadean, Proterozoic, Phanerozoic Hadean, Archaean, Proterozoic, Phanerozoic Phanerozoic, Hadean, Archaean, Proterozoic |
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d |
Which statement is correct? ANSWER: A synapomorphy is an ancestral trait. A synapomorphy may arise due to covergent evolution. Synapomorphies are examples of homoplasy. Synapomorphies identify monophyletic groups. |
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c |
What is exceptional about the Burgess Shale, Doushantuo, and Ediacaran faunas? ANSWER: These faunas contain the oldest known fossils on Earth. The faunas contain only jellyfishes, sponges, and simple worms. Soft-bodied animals are well-represented in these faunas. These faunas are very low in species diversity. |
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c |
How did Ediacaran animals differ from Burgess Shale animals? ANSWER: Ediacaran animals housed mutualistic bacteria. Ediacaran animals were larger. Ediacaran animals lacked mouths and digestive tracts. Ediacaran animals were more active. |
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a |
Which is the best definition of adaptive radiation? ANSWER: An adaptive radiation occurs when a single lineage produces many ecologically diverse descendant species in a relatively short period of time. An adaptive radiation is a group of rapid speciation events. An adaptive radiation is a star phylogeny. An adaptive radiation is the evolution of a novel trait that makes new ecological opportunities available. |
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c |
How can mass extinction events be distinguished from background extinctions? ANSWER: During a mass extinction, species die out because individuals are poorly adapted to normal or gradually changing environmental conditions. Mass extinctions result primarily from natural selection. A mass extinction occurs when at least 60 percent of species are wiped out within 1 million years. Mass extinctions occur when normal environmental change eliminates certain populations to zero. |
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a |
What evidence supports the impact hypothesis for the end-Cretaceous extinction? ANSWER: Sedimentary rocks from the K-P boundary layer contain large amounts of iridium. Most dinosaurs, with the exception of the birds, went extinct at this time. The Earth cooled considerably during the end-Cretaceous extinction. The largest flood basalts on Earth, called the Siberian traps, occurred during the end-Cretaceous. |
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