Which of the following is probably the best explanation for the fact that Antarctic penguins

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In a small group of people living in a remote area, there is a high incidence of "blue skin" a condition that results from a variartion in the structure of hemoglobin. All of the "blue-skinned" resident can trace their ancestry to one couple,e who were among the original settlers of this region. The unusually high frequency of "blue skin" in the area is an example of....a-genetic driftb-heterozygote advantagec-natural selection
d-mutation

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Which of the following is probably the best explanation for the fact that Antarctic penguins cannot fly, although there is evidence that millions of years ago their ancestors could do so? a-Ancestral penguins did not use their wings for long periods of time; therefore today's penguins have only tiny, nonfunctional wings. b-ancestral penguins without large wings were better able to swim and feed in the water; therefore they passed their genes for shorter wing structure on to their offspringc-the Antarctic home of penguins is flat and barren; therefore there is no place to fly
d-Penguins live on land and feed in the water; therefore they have no need to fly.

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The bones of a human arm are homologous to structures in all of the following EXCEPT a....a-whale flipperb-bird wingc-butterfly wing
d-frog forelimb

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The different species of finches on the Galapagos Islands are believed to have arisen as a result of the natural selection acting on populations of finches that had experienced...a-geographic isolationb-the bottleneck effectc-gene flow
d-convergent evolution

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Which of the following principles is NOT part of Darwin's theory of evolution by natural selection? a-mutations are the ultimate source of genetic variationb-individuals that possess the most favorable variations have the best chance of reproducingc-variation occurs among individuals in a population
d-more individuals are born than will survive

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Some varieties of Neisseria gonorrhoeae are now resistant to penicillin. These varieties of bacteria most probably developed as a result of....a-natural selectionb-convergent evolutionc-coevolution
d-adaptive radiation

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Although the seal and the penguin both have streamlined, fishlike bodies with a layer of insulating fat, they are not closely related. This similarity results from...a-adaptive radiationb-coevolutionc-convergent evolution
d-parallel evolution

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The condition in which tere are barriers to successful interbreeding between individuals of different species in the same community is referred to as...a-reproductive isolationb-geographic isolationc-sterility
d-structural differences

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A new species of organism has evolved when....a-variation has occurred within the species due to mutationsb-a population can no longer interbreed under natural conditions with other closely related organismsc-a selection pressures have produced a group of demes
d-a population has been recently isolated from the rest of the species by a geographic barrier

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The introduction of antibiotics such as penicillin several years ago was immediately effective in combating infections cuased by Staphylococcus. In 1958 however, there were several outbreaks of staphylococcal infections. People with the infections did not respond to treatment with any of the antibiotics and there was a large number of deaths. The best explanation for this situation is that....a-each generation of bacteria acquired the ability to use the antibiotics as nutrients b-antibitotic-resistant bacteria survived and multiplied, and these were the forms causing the infections c-the bacteria exposed to non-lethal doses of antibiotics quickly learned to avoid them
d-the bacteria reproduced in hosts that were not contaminated with antibiotics

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Which of the following best supports the statement that mitochondria are descendants of endosymbitoic bacteria-like cells? a-Mitochondria and bacteria possess similar nucleib-neither mitochondria nor bacteria possess chloroplastsc-mitochondria and bacteria possess similar ribosomes and DNA
d-glycolysis occurs in both mitochondria and bacteria

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The wing of a bat, the flipper of a whale, and the forelimb of a horse appear very different, yet detailed studies reveal the presence of the same basic bone pattern. These structures are examples of...a-vestigal structuresb-homologous structures
c-analogous structures

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All of the following conditions should result in a change in the frequency of a specific allele in a population EXCEPT a-mutation of the dominant allele to the recessive allele b-genetic driftc-random mating in a large population
d-seleection against the recessive phenotype

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Which of the following statements best describes the effect of genetic drift on the gene frequencies of a population?a-mutations over time cause gene frequencies to changeb-selection against one allele causes gene frequencies to changec-chance alone can cause significant changes in gene frequencies of small populations
d-genes enter a population through immigration, thus changing gene frequencies

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A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 36% of the animals display a recessive trait (aa), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants. What is the most reasonable conclusion that can be drawn from the fact that the frequency of the recessive trati (aa) has not changed over time?a-the two phenotypes are about equally adaptive under laboratory conditionsb-there has been a high rate of mutation of allele A to allele ac-the genotype AA is lethal
d-the population is undergoing genetic drift

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A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 36% of the animals display a recessive trait (aa), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants. All of the following are criteria for maintaining Hardy-Weinberg equilibrium involving two alleles EXCEPT...a-populations must be large b-there should be no natural selectionc-matings must be random
d-the frequency of all genotypes must be equal

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A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 36% of the animals display a recessive trait (aa), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants. In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is .7. What is the percentage of the population that is homozygous for this allele?a-42b-9c-49
d-30

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A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 36% of the animals display a recessive trait (aa), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants. In a population with two alleles, A and a, the frequency of a is .50. What would be the frequency of heterozygotes if the population is in Hardy-Weinberg equilibrium?a-.75b-.50c-.25
d-1.0

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In a hypothetical population of 1000 people, tests of blood-type genes show that 160 have the genotype AA, 480 have the genotype AB and 360 have the genotype BB.What is the frequency of the A allele? a-.001b-.1c-.400
d-.002

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Toads in a particular population vary in size. A scientists ovserves that in this population, large males mate with females significantly more often that the small moles do. All the following are plausible hypotheses to explain this observation EXCEPT:a-small females are more likely to mate with small males and large females are more likely to mate with large malesb-females select large males more often than they select small males as matesc-the calls produced by large males are more attractive to females than the calls made by small males
d-large males are successful in competing for mates more often than small males are

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Which of the following provides the weakest evidence that mitochondria were once free-living prokaryotes? a-enzyme pathways on mitochondrial membranes resemble those found on modern prokaryote membranesb-mitochondrial ribosomes resemble those of prokaryotesc-mitochondria and prokaryotes both are found in a variety of sizes
d-mitochondrial have DNA that is circular and does not have associated protein

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