Let’s suppose that weight in a species of mammal is polygenic, andeach gene exists as a heavy and light allele. If the allele frequenciesin the population are equal for both types of alleles (i.e., 50%heavy alleles and 50% light alleles), what percentage of individualswill be homozygous for the light alleles in all of the genesaffecting this trait, if the trait was determined by the followingnumber of genes?A. TwoB. ThreeC. Four

Let’s suppose that weight in a species of mammal is polygenic, andeach gene exists as a heavy and light allele. If the allele frequenciesin the population are equal for both types of alleles (i.e., 50%heavy alleles and 50% light alleles), what percentage of individualswill be homozygous for the light alleles in all of the genesaffecting this trait, if the trait was determined by the followingnumber of genes?A. TwoB. ThreeC. Four

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter19: Population Genetics And Human Evolution

Section: Chapter Questions

Problem 2QP: How Can We Measure Allele Frequencies in Populations? The MN blood group is a single-gene,...

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Alkaptonuria is a recessive autosomal genetic disorder associated with darkening of the urine. In the United States, approximately 1 out of every 250,000people has alkaptonuria.a. Assuming Hardy-Weinberg equilibrium, estimatethe frequency of the allele responsible for this trait.b. What proportion of people in the U.S. populationare carriers for this trait? In this population, whatis the ratio of carriers to individuals affected byalkaptonuria?c. If a woman without alkaptonuria had a child withthis trait with one husband then remarried, what isthe chance that a child produced by her secondmarriage would have alkaptonuria?d. Alkaptonuria is a relatively benign condition, sothere is little selective advantage to individualswith any genotype; as a result, your assumptionof Hardy-Weinberg equilibrium in part (a) is reasonable. Could you also use the assumption ofHardy-Weinberg equilibrium to estimate the allelefrequencies and carrier frequencies of more severerecessive autosomal conditions…
At the molecular level, explain why quantitative traits often exhibita continuum of phenotypes within a population. How does theenvironment help produce this continuum?
A certain form of congenital glaucoma is caused by an autosomalrecessive allele. Assume that the mutation rate is 10-5 and that peoplewith this condition produce, on the average, only about 80% of theoffspring produced by people who do not have glaucoma.a. At equilibrium between mutation and selection, what will the frequencyof the gene for congenital glaucoma be?b. What will the frequency of the disease be in a randomly matingpopulation that is at equilibrium?
Consider a rare deleterious recessive allele for a specific gene/locus. In this hypothetical population, the deleterious recessive allele exists at a proportion of 0.01. In an offspring with randomly chosen parents, what is the probability that the offspring will be homozygous for the deleterious recessive allele [q]?
Different species of crickets have distinct songs, andthey use these songs for mate recognition. Researcherscrossed two species of Hawaiian crickets (Laupala paranigra and L. kohalensis) whose songs are distinguishedby pulse rate (the number of pulses per second; Shaw etal., Molecular Ecology 16, 2007, 2879–2892.) Then, theymapped QTL in the F2 population derived from thiscross. Six autosomal QTL were detected. The mean traitvalues (pulses per second) at the three genotypic classesin the F2 for each QTL are shown in the table below,where P indicates the L. paranigra allele and K indicatesthe L. kohalensis allele.a. Calculate the additive (A) and dominance (D) effectsand the D/A ratio for each of the six QTL.b. Which of these QTL shows the greatest amount ofdominance?c. Which of these has the largest additive effect?d. The mean pulse rate for L. kohalensis is 3.72, and it is0.71 for L. paranigra. Do all six QTL act in the expecteddirection with the L. kohalensis allele conferring a…
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