OMutation-selectionbalanceSuppose that one allele A₁ mutates to another allele A2 at some rate, μ.Suppose as well that A₁ is dominant over A2 such that A₁A1 and A₁A2 bothhave the same fitness, but that individuals that are homozygous recessive(A2A2) for the mutant allele A2 are less fit than the dominant genotype bysome amount s, the selection coefficient. In this case, A2 mutant alleles comeinto the population at rate µ, and are removed from the population onlywhen the show up in homozygous genotypes. The gory mathematical proofcan be found in Box 7.8, which tells us that:O■Example: Suppose A₁ mutates to A2 at rate 0.005, but A₂A2 homozygousrecessives are 50% less fit (s = 0.5) than either A₁A1 or A₁A2. What are theexpected equilibrial abundances of A₁ and A2?μ = 0.005S = 0.5p* = 1-sqrt(µ/s) = 1-sqrt(0.005/0.5) = 0.9= sqrt(µ/s) = sqrt(0.005/0.5) = 0.1●*p = = 1-sqrt(µ/s)q* = sqrt(μ/s)●Question: Suppose A₁ mutates to A2 at rate 0.01, but A₂A2 homozygousrecessives are 40% less fit (s = 0.4) than either A₁A1 or A1A2. What are theexpected equilibrial abundances of A₁ and A₂?8

Hardy Weinberg Equilibrium explains how allele and gene frequency remain same in the population from…

Answered: O ■ Example: Suppose A₁ mutates to A2…

Concepts of Biology

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ISBN:9781938168116

Author:Samantha Fowler, Rebecca Roush, James Wise

Publisher:Samantha Fowler, Rebecca Roush, James Wise

Chapter8: Patterns Of Inheritance

Section: Chapter Questions

Problem 11RQ: The ABO blood groups in humans are expressed as the IA,IB and i alleles. The IAallele encodes the A...

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Mutation O Silent mutation from one allele to another ■ Suppose one allele (A1) mutates to another (A2) at some rate, μ, each generation within a population, and A2 mutates to A1 at some other rate, v. Suppose also that A1 and A2 are selectively neutral - they confer equal fitness. what is the equilibrial frequency of each of the two alleles (p* and q*)? You can think of the mathematical result as p* being the mutation rate towards A1 divided by the sum of the mutation rates. OR, p* is the proportion of all mutation rates (µ+v) that is mutation in the A1 direction (v). See box 7.7. ● ● ● μ = mutation from A1 to A2 v = mutation from A2 to A1 p* = v/(μ+v) Example: A1 mutates to A2 in 0.0004 of all offspring per generation. In other words the probability of mutation from A1 to A2 is 0.0004. A2 mutates to A1 in 0.0001 of all offspring per generation. What is the expected equilibrial abundance A1 and A2? μ = mutation from A1 to A2 = 0.0004 v = mutation from A2 to A1 = 0.0001 p* = v/(μ+v) =…
a. Alleles of genes on the X chromosome can also be atequilibrium, but the equilibrium frequencies underthe Hardy-Weinberg assumptions must be calculatedseparately for the two sexes. For a gene with two alleles A and a at frequencies of p and q, respectively,write expressions that describe the equilibrium frequencies for all the genotypes in men and women.b. Approximately 1 in 10,000 males in the UnitedStates is afflicted with hemophilia, an X-linkedrecessive condition. If you assume that the population is at Hardy-Weinberg equilibrium, what proportion of American females would be hemophiliacs?About how many female hemophiliacs would youexpect to find among the 170 million women livingin the United States? (Assume that all females withhemophilia are homozygous for the disease allele.)
. Considering the yellow and green pea color phenotypes studied by Gregor Mendel:a. What is the biochemical function of the proteinthat is specified by the gene responsible for thepea color phenotype?b. A null allele of a gene is an allele that does notspecify any of the biochemical function that thegene normally provides. Of the two alleles Y and y,which is more likely to be a null allele?c. In terms of the underlying biochemistry, why is theY allele dominant to the y allele?d. Why are peas that are yy homozygotes green?e. The amount of the protein specified by a gene isroughly proportional to the number of functionalcopies of the gene carried by a cell or individual.What do the phenotypes of YY homozygotes, Yyheterozygotes, and yy homozygotes tell us aboutthe amount of the Sgr enzyme (the product of thepea color gene) needed to produce a yellow color?
Prediction If your hypothesis is correct, what will be the predicted ratio of phenotypes in your F, generation? (Punnett square may be used to explain) etv O MacBook Pro 三) 14 @ & 1 2 3 4 6 8. 9 Q W E R T Y P A J K く > C V option command command このつエの

. The production of pigment in the outer layer of seedsof corn requires each of the three independently assorting genes A, C, and R to be represented by at leastone dominant allele, as specified in Problem 64. Thedominant allele Pr of a fourth independently assortinggene is required to convert the biochemical precursorinto a purple pigment, and its recessive allele pr makesthe pigment red. Plants that do not produce pigmenthave yellow seeds. Consider a cross of a strain of genotype A/A ; C/C ; R/R ; pr/pr with a strain of genotypea/a ; c/c ; r/r ; Pr/Pr.a. What are the phenotypes of the parents?b. What will be the phenotype of the F1?c. What phenotypes, and in what proportions, willappear in the progeny of a selfed F1?d. What progeny proportions do you predict from thetestcross of an F1?
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?
a. Two linked biallelic loci (c = 0.1) have allele frequencies pA = 0.7 and pB = 0.4. If these two sites are in linkage disequilibrium with D = -0.12, what are the expected haplotype frequencies under these conditions? b. What will the linkage disequilibrium parameter D be after 20 generations?
F1 hybrids between two species of cotton, Gossypium barbadenseand Gossypium hirsutum, are very vigorous plants. However, F1crosses produce many seeds that do not germinate and a high percentageof very weak F2 offspring. Suggest two reasons for theseobservations.
stion 6 of 18 Suppose that a geneticist discovers a new mutation in Drosophila melanogaster that causes the flies to shake and quiver. She calls this mutation quiver, qu, and determines that it is due to an autosomal recessive gene. She wants to determine whether the gene encoding quiver is linked to the recessive gene for vestigial wings, vg. She crosses a fly homozygous for quiver and vestigial traits with a fly homozygous for the wild-type traits, and then uses the resulting F, females in a testcross. She obtains the flies from this testcross. Phenotype Number of flies vg* qu+ 230 vg qu 224 vg qut vg* qu 97 99 Test the hypothesis that the genes quiver and vestigial assort independently by calculating the chi-squared, X², for this hypothesis. Provide the X2 to one decimal place. X2 = Does the X value support the hypothesis that the quiver and vestigial genes assort independently? Why or why not? the partial table of critical values for X2 calculations to test this hypothesis.
Pitcher plants can take many forms. You are interested in understanding the genetic control of pitcher formation in pitcher plants. Which of the following is not likely a result you would expect from your QTL study? AV O a. Variation in pitcher size in your F2 population does not exceed that of your parental generation. O b. You were able to reconstitute the phenotypes of the parental generation by selectively breeding F2 individuals. O c. The variation in phenotypes is greater in the F1 population compared to the F2 population. O d. The phenotypes you are interested exhibit a typical Mendelian inheritance.
dd-ons Help в I U A Calibri 12 三三1 |:三 6. Consider a guinea pig with a homozygous genotype and a white fur color phenotype. a. What is the probability this parent will produce a gamete with the dominant allele? b. What is the probability this parent will produce a gamete with the recessive allele? C. If 31 sperm cells are collected from this guinea pig, how many would you expect to have the recessive allele (as determined by sequencing the gene)? !!!
Frequency 12% (0) Cross-over frequencies for some genes on a tomato plant: Use the following information to answer the next question. (S) a. C. 64% tall plant (D) and normal tomato (0) 21% Select one: d. normal leaf (M) and tall plant (D) normal leaf (M) and normal tomato 33% normal leaf (M) and simple inflorescence (S) The cross-over frequency between genes O and S is tall plant (D) and simple inflorescence 52% b. 29% Genes 31% 97% Cross-Over 6% O

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