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Phenotype number genotype yellow bodies wild type

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Phenotype Number Genotype Yellow bodies, Wild type wings 60 ____aB/ab__________ Wild type bodies, Crossveinless wings 65 ____Ab/ab__________ Yellow bodies, Crossveinless wings 35 ____ab/ab__________ Wild type bodies, Wild type wings 40 ____AB/ab_________ a) Given this information, what are the genotypes of the female and male parent flies from this cross? If applicable, indicate the phase of linkage. (2 points) aB/Ab x ab/ab b) In the spaces provided on the table above, indicate the genotype of each class of progeny. If applicable, indicate the phase of linkage. (4 points) see above c) Is there evidence for linkage of these two loci? If so, provide the recombination frequency, and calculate the chi-square value and approximate p value for the comparison between the hypothesis that these loci are linked to the null hypothesis that these loci are unlinked (see table at the end of the exam). Show your work for full credit. (4 points) The recombination frequency = 75/200=37.5% X2=(75-100)^2/100+(125-100)^2/100 = 12.5 dof = 2-1 = 1; p value <0.001 We can reject the null hypothesis that these loci are unlinked. The data suggests that two loci are linked. 4
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Name________________________________ 5 . The distance between two or more loci can be measured in physical distance (base pairs) or in genetic distance (recombination frequency). Explain how two pairs of loci that are the same physical distance apart can vary with respect to their genetic distances. (3 points) Two pairs of loci that are the same physical distance apart can vary with respect to their respective genetic distances because recombination frequency is not uniform across the genome (e.g. “hot spots”). Regions of high or low recombination exist along each chromosome resulting in the inheritance of genetic material in chunks called haplotypes. This phenomenon can also be explained by differences in interference. Note, however, that while multiple crossover events and the 50% limit in recombination frequency are reasons why genetic distance and physical distance are not equivalent, they are not relevant comparisons in this question (two pairs of loci that are the same physical distance apart). For example, if two pairs of loci were each very far apart, they would have the same genetic distance (50% recombination). 6 . Diagram human male meiosis, with sufficient detail to show the migration of chromosome 1 and the sex chromosomes. In your diagram, indicate where crossing over, segregation of alleles, and independent assortment occur. (6 points) Draw Chromosomes 1 and XY, show how homologs and then sister-chromatids are separated Name Meioses I with Prophase I (Crossover), Metaphase I (independent assortment), Anaphase I (segregation of alleles), Telophase I; (Cytokinesis); Meioses II with Prophase II, Metaphase II, Anaphase II (can also have segregation of alleles) and Telophase II. 4 haploid sperms.
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Phenotype Number Genotype Yellow bodies Wild type wings 60...

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