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| 1 | A change in the frequency of alleles in a population is the definition of |
 | A) | natural selection. |
| B) | genetic drift. |
| C) | evolution. |
| D) | gene flow. |
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| 2 | The study of genetic events that occur in gene pools is called |
| A) | evolutionary genetics. |
| B) | population genetics. |
| C) | gene pool biology. |
| D) | allopatry. |
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| 3 | If the requirements of the Hardy-Weinberg theorem are all met, then |
| A) | evolution is occurring rapidly. |
| B) | evolution is occurring slowly. |
| C) | evolution is not occurring. |
| D) | gene frequencies are changing. |
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| 4 | Which of the following statements is most accurate? |
| A) | Evolution is always occurring in all populations. |
| B) | Evolution occurs in virtually all populations at some point in their history. |
| C) | Evolution rarely occurs in any population. |
| D) | Evolution never occurs. |
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| 5 | Two tortoises are caught on a mat of floating vegetation and get carried out to sea. Their mat happens to land on a volcanic island that is inhabited by a small population of the same species. Breeding with the island tortoise population introduces new alleles that add to the genetic diversity of tortoises on the island. This account is an example of |
| A) | genetic drift. |
| B) | gene flow. |
| C) | natural selection. |
| D) | neutral selection. |
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| 6 | After a bottleneck event has occurred |
| A) | the genetic diversity of a population is greater. |
| B) | the genetic diversity of a population is decreased. |
| C) | the size of the population always increases. |
| D) | the size of the population always decreases. |
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| 7 | When chance events increase or decrease the frequencies of alleles in a population, _______ has occurred. |
| A) | genetic drift |
| B) | natural selection |
| C) | random mating |
| D) | gene flow |
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| 8 | From the perspective of a population, mutations are positive events because |
| A) | they weed out less fit individuals. |
| B) | they provide new genetic variations that can help enhance the survival of the species. |
| C) | most mutations make individuals stronger. |
| D) | they are always expressed when they occur. |
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| 9 | When a geographical barrier divides members of a population, ______ speciation may occur. |
| A) | sympatric |
| B) | allopatric |
| C) | stabilizing |
| D) | directional |
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| 10 | A mutation that caused a change in courtship behavior occurred in, and spread among, a few members of a population of cranes. This change in courtship behavior prevents those that have the mutation from mating with those that do not have the mutation, even though the two groups share the same breeding territory. This mutation may cause _________ speciation. |
| A) | sympatric |
| B) | allopatric |
| C) | stabilizing |
| D) | directional |
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| 11 | The punctuated equilibrium model of evolution describes the theory that |
| A) | evolution occurs very slowly and steadily over long periods of time. |
| B) | evolution occurs at a constant, rapid rate. |
| C) | evolution occurs rapidly for short periods of time and then a population undergoes very little change for long periods of time. |
| D) | evolution does not occur. |
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| 12 | Natural selection that narrows the phenotypic range by selecting against phenotypic extremes is called |
| A) | disruptive selection. |
| B) | stabilizing selection. |
| C) | directional selection. |
| D) | neutral selection. |
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| 13 | Sickle-cell anemia was maintained in African populations because the heterozygote was resistant to malaria. Both homozygotes were selected against by severe sickling or susceptibility to malaria. This example illustrates |
| A) | directional selection. |
| B) | disruptive selection. |
| C) | neutral selection. |
| D) | heterozygote superiority. |
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| 14 | All genes in an organism do not necessarily change at the same rate. Most cats, for example, are easily recognized as cats. These traits have been conserved in evolution. Other traits (e.g., length of the tail, pelage, and stature) vary from species to species. This is an example of |
| A) | molecular evolution. |
| B) | mosaic evolution. |
| C) | gene duplication. |
| D) | phyletic gradualism. |
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| 15 | In order for speciation to occur, some members of a population must be reproductively isolated from other members of the population. |
| A) | True |
| B) | False |
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| 16 | Genetic drift is most likely to occur in large populations. |
| A) | True |
| B) | False |
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| 17 | The change in the frequency of body color alleles in peppered moths in England during the industrial revolution was an example of directional selection. |
| A) | True |
| B) | False |
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| 18 | The formation of a physical barrier that divides one population into two groups is an example of postmating isolation. |
| A) | True |
| B) | False |
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| 19 | An allele that has been conserved evolutionarily would be present in most members of a group. |
| A) | True |
| B) | False |
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| 20 | Phyletic gradualism is attractive to many paleontologists because it explains the absence of fossils that document transitional forms between related organisms. |
| A) | True |
| B) | False |
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| 21 | Speciation that occurs in small, local populations is called parapatric speciation. |
| A) | True |
| B) | False |
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| 22 | Evolution invariably leads to some kind of improvement in a species. |
| A) | True |
| B) | False |