TABLE 20-3 The Dependence of the Fitness Effects of Mutations on Prior Mutations in E. coli Mutation* Number of alleles on which mean Mean proportional mutational effect is increase Positive Negative Negligible g4205a 8 1.4 A42G 12 4 5.9 E104K 15 1 9.7 M182T 8 3 5 2.8 G238S 16 1.0 x 103 "The mutations leading to antibiotic resistance are designated by their nucleotide or amino acid position. Of the 16 possible allelic combinations of the four other sites, the positive, negative, or neutral effects of the mutation are indicated along with the mean proportional increase in fitness for mutations at the indicated site.

TABLE 20-3 The Dependence of the Fitness Effects of Mutations on Prior Mutations in E. coli Mutation* Number of alleles on which mean Mean proportional mutational effect is increase Positive Negative Negligible g4205a 8 1.4 A42G 12 4 5.9 E104K 15 1 9.7 M182T 8 3 5 2.8 G238S 16 1.0 x 103 "The mutations leading to antibiotic resistance are designated by their nucleotide or amino acid position. Of the 16 possible allelic combinations of the four other sites, the positive, negative, or neutral effects of the mutation are indicated along with the mean proportional increase in fitness for mutations at the indicated site.

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter5: The Inheritance Of Complex Traits

Section: Chapter Questions

Problem 22QP: Height in humans is controlled by the additive action of genes and the action of environmental...

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. Figure 18-14 presents haplotype data for the G6PD genein a worldwide sample of people.a. Draw a haplotype network for these haplotypes.Label the branches on which each SNP occurs.b. Which of the haplotypes has the most connectionsto other haplotypes?c. On what continents is this haplotype found?d. Counting the number of SNPs along the branchesof your network, how many differences are therebetween haplotypes 1 and 12?
For three years, Gunther Schlager and Margaret Dickie estimated theforward and reverse mutation rates for five loci in mice that encodevarious aspects of coat color by examining more than 5 million mice forspontaneous mutations (G. Schlager and M. M. Dickie. 1966. Science151:205–206). They detected the following numbers of mutations at thedilute locus: Gametes examined Mutations detectedForwardmutations 260,675 5Reversemutations 583,360 2 Calculate the forward and reverse mutation rates at this locus. If thesemutations rates are representative of rates in natural populations of mice,what would the expected equilibrium frequency of dilute mutations be?
Consider the case of a hypothetical genetic disease called WhySciEleven (WSE), an inherited disease that results to the inability to complete production of an amino acid “moduleactivity” that results in brain damage if untreated. WSE is due to a recessive allele. Given one WSE occurrence per 10,000 births. Which term in the Hardy-Weinberg equation corresponds to the frequency of individuals who have no alleles for the disease WSE? a. p b. 2pq c. p2 d. q2
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please tell us the expected average time to fixation of an allele at frequency p = 0.5 in a population of 100 individuals, we can safely assume that the allele does become fixed?
n class we investigated the reason cystic fibrosis is maintained in the human population in higher frequency than we expected given the deleterious effects of being homozygous at the CFTR gene. We calculated the actual mutation rate of the CFTR gene to be 6.7 x 10-7. The mutation rate expected under mutation-selection balance was 4 x 10-4. What is the most plausible explanation as to why cystic fibrosis is maintained in the human population at a higher frequency than we expect? a. Negative selection against the CFTR deleterious alleles is too weak to eliminate the alleles from the human population. b. Positive selection for the CFTR deleterious alleles is likely occurring in response to some other selective pressure in the human population, possibly resistance to typhoid fever. c. The CFTR gene has an exceedingly low mutation rate causing humans to have no genetic variation at that gene. d. The CFTR gene has an exceedingly high mutation rate and that is…
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