Evolution is one of the unifying themes of biology. Evolution involves change in the frequencies of alleles in a population. For a particular genetic locus in a population, the frequency of the recessive allele (a) is 0.4 and the frequency of the dominant allele (A) is 0.6. (c) Identify a particular environmental change and describe … Read more
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On a large volcanic island, researchers are studying a population of annual herbaceous plants. Which of the following observations best supports the prediction that speciation will occur within the existing plant population? a) Individuals of the species sometimes reproduce asexually by producing runners. b) Lava has separated the population into two areas: an upland forest … Read more
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A scientist is studying a population of lizards with three different color phenotypes. The color phenotype is controlled by a single gene with two alleles: an incompletely dominant allele A and a recessive allele a. The scientist collected data on the color of 100 lizards. The data are shown in the table. RED AA 75PURPLE … Read more
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Goats and sheep belong to the same family but different genera. While they often live together in the same pastures, the hybrid offspring that are occasionally produced between the two species rarely survive. When such a hybrid does survive, it is usually sterile. Which of the following best explains the mechanism that maintains reproductive isolation … Read more
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Figure 1 compares two models of speciation, A and B. Which of the following best explains how the ecological conditions are likely to be different in the two models? a) In model A the ecological conditions remain unchanged for long periods of time and then change drastically; in model B the ecological conditions change drastically … Read more
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Assuming that the population was in Hardy-Weinberg equilibrium for the G locus, what percentage of moths in the natural population was white in 1962? a) 2% b) 4% c) 8% d) 20% e) 64%
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