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. (b) How can the Hardy-Weinberg principle of genetic … Read more
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The condition in which there are barriers to successful interbreeding between individuals of different species in the same community is referred to as a) latent variations b) sterility c) structural differences d) geographic isolation e) reproductive isolation
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A survey reveals that 25 percent of a population of 1,000 individuals have attached earlobes (are homozygous recessive for the trait). Unlike most natural populations, this population is best characterized in which of the following ways? a) there is a genetic equilibrium b) there is gene flow c) there is genetic drift d) mutations occur … Read more
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Female European corn borer moths (Ostrinia nubilalis) produce the sex pheromone 11−tetradecenyl acetate (11−TDA), which attracts males of their species. 11−TDA can be produced in two forms, E and Z, each with a different three-dimensional shape. Researchers have discovered two different strains of the European corn borer moth living in the same area. Females of … Read more
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Which of the following statements best expresses the concept of punctuated equilibrium? a) Small variations gradually accumulate in evolving lineages over periods of millions of years. b) Random mating ensures that the proportions of genotypes in a population remain unchanged from generation to generation. c) Stability is achieved when selection favors the heterozygote, while both … Read more
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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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