7 03 Exam 1 2009 Name TA KEY Jason Funt Wendy Niedelman David Gifford Amuda Panneerselvam Sarah Pfau Yun Sung Section time There are 6 pages including this cover page Please write your name on each page 1 30 points You have two haploid strains of yeast that have adenine mutations one is adex trp1 and the other is adey Trp1 The adenine and tryptophan pathways are controlled by different genes You mate the strains and obtain a diploid that is Trp Ade requires only adenine A 5 points Given these data select all statements that are consistent with the data a adex and adey are mutations in different genes b adex and adey are mutations in the same gene c adex and adey are recessive mutations in different genes d adex is a dominant mutation a b d B 12 points You examine 100 meiotic tetrads and obtain the following results trp adex trp adex adey adey 70 trp adex adex adey trp adey trp adex trp adex adey adey 10 20 Draw a map showing any linked genes and the map distances ade x tr p 5 10 ade y C 5 points Given the new data which of these statements is consistent with the data a adex and adey are mutations in different genes b adex and adey are mutations in the same gene c adex and adey are recessive mutations in different genes d adex is a dominant mutation a d D 4 points What is the probability of all double crossovers P adex trp P trp adey 05 x 10 005 E 4 points What is the probability of finding a tetrad with the following constitution trp adex adex trp adey adey NPD 1 4 of all double crossovers So 1 4 x 005 2 18 points In Neurospora three different genes are needed for production of black pigment in spores Recessive alleles at any one of these result in white spores Three crosses of wild type by a mutant containing a different blk mutation were analyzed 120 asci cross Remember that in Neurospora the position of the spores in the ascus is related to the position of chromatids at the first meiotic division Cross 1 blk1 x wild type Cross 2 blk2 x wild type Cross 3 blk3 x wild type Asci observed from Cross 1 Cross2 Cross3 1 6 0 20 2 6 0 20 3 48 60 20 4 6 0 20 5 6 0 20 6 48 60 20 For each cross show a map indicating what you can deduce about the location of the segregating gene blk1 Cross 1 6 points Blk1 10 cM from centromere blk2 Cross 2 6 points Blk2 100 linked to centromere blk3 Cross 3 6 points Blk3 unlinked to centromere sn r 3 22 You cross singed X X sn female fruit flies by rasberry males X Y Rasberry and singed are on the X chromosome This cross gave rise to F1 progeny that are all wild type You notice that the F1 females have occasional spots on their bodies that reveal recessive markers Some flies have twin spots where one tissue is singed and the other is rasberry Others have only a single singed spot You never find flies that have only a rasberry spot singed rasberry singed a 6 Draw the event that gave rise to the twin spot s ns n r r s n r r singed rasberry r r sn singed r sn Wild type r s n b 6 Draw the event that gave rise to singed r r s ns n s n r r s n s n s n c 10 Based on these data draw the order of these genes with respect to the centromere cen r sn 4 30 Please answer the following questions in the context of the pedigree provided Assume that individuals that are affected with a dominant trait are heterozygous for the trait We do not know if individuals that are marked with are affected or not a 8 points For each mode of inheritance if the mode of inheritance is not possible given the pedigree write Not Possible next to the mode of inheritance Otherwise provide the probabilities for Events A and B as defined Event A Individual 6 is a carrier given it is not affected Event B Individual 7 is a carrier given it is not affected Autosomal Dominant Autosomal Recessive X Linked Recessive X Linked Dominant P A Not Possible 2 3 Not Possible P B Not Possible 1 0 Not Possible b 4 points Give the probability Individual 9 is affected assuming an autosomal recessive trait Event C 9 is affected assuming an autosomal recessive trait Event D 6 is a carrier assuming an autosomal recessive trait Event E 7 is a carrier assuming an autosomal recessive trait P C P D x P E x 2 3 x 1 x 1 6 c 4 points Assuming an autosomal recessive trait what is the probability that Individual 6 is a carrier given that Individual 9 is not affected P D not C P not C D P D P not C P D not C x 2 3 1 P C x 2 3 5 6 3 5 d 7 points Assuming an autosomal recessive trait what is the probability that Individual 10 is affected given that Individual 9 is not affected Event F 10 is affected assuming an autosomal recessive trait P F not C P F DE P D not C P E not C x 3 5 x 1 3 20 e 7 points Assuming an X linked recessive trait what is the probability that Individual 10 is a carrier given that Individual 9 is not affected Event G 6 is a carrier assuming an X linked recessive trait Event H 9 is not affected assuming an X linked recessive trait Event J 10 is a carrier assuming an X linked recessive trait P G P H 1 P G x 3 4 P G H P H G P G P H x 1 3 P J H P G H x 1 6 Question 1 pts Question 2 pts Question 3 pts 7 03 EXAM TWO FALL 2008 Name TA Circle One Section David Gifford M1 Amudha Panneerselvam M2 Jason Funt M3 M4 Wendy Niedelman T10 T11 Sarah Pfau T12 T1 Yun Song T2 M2 There are 3 questions 8 pages including this cover page Please write your name on each page Please Look over the entire exam so you don t spend too much time on hard parts of questions leaving easy parts of questions unanswered Check your answers to make sure that they make sense To help us give partial credit show your work and state any assumptions that you make where appropriate ONLY ANSWERS WRITTEN ON THE EXAM WILL BE GRADED WRITE ANSWERS IN THE SECTIONS PROVIDED IN THE EXAM 1 1 30 You are working a diploid organism that has a mutation to white eye w that reverts to the wild type red eye The original white eye mutation on an autosome is recessive to red eye …
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