Exams Fall 2000 7 03 Exam 1 Name Section TA Exam starts at 11 05 and ends at 11 55 There are seven pages including this cover page Please write your name on each page Also Look over the entire exam so you don t spend too much time on hard questions leaving easy 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 Question I 35 points Question 2 35 points Question 3 30 points Name 1 a 4 pts Wild type yeast form white colonies You have isolated two mutants that make red colonies that you call red1 and red2 When a redl mutant is mated to a red2 mutant of the opposite mating type the resulting diploid makes white colonies What does this observation tell us about redland red2 b 9 pts When the diploids are found from part a are sporulated three types of tetrads Type I have 4 red colonies Type II have 1 white and 3 red colonies Type III have 2 white and 2 red colonies Classify each tetrad type as PD NPD or T Type I c 10 pts Type II Type III When the number of each tetrad type is tallied you find that the cross produces 30 Type I tetrads 16 Type II tetrads and 4 Type III tetrads Are the red1 and red2 mutations linked If so how far apart are they in cM Name d 12 pts One of the Type II tetrads from above is selected for further analysis and you designate the four spore clones a b c and d Clone a is white whereas clones b c and d are red Each clone is mated to either a redlmutant or a red2 mutant and the color of the resulting j x red1 white diploid Clone a white x red2 white diploid x red1 red diploid Clone b red x red2 white diploid x red1 red diploid Clone c red x red2 red diploid x red1 white diploid Clone d red x red2 red diploid Give the genotypes Clone a Clone b Clone c Clone d of each of the four spore clones diploid is noted Name 2 Consider the following pedigree where two first cousins have a son Each individual is numbered for reference in this problem 4 a 15 pts Say that female 1 is affected by a rare recessive X linked trait and that male 2 does not have the trait Assume that individuals 3 and 6 neither have nor are carriers of the trait What is the probability that male 4 will be affected by the trait What is the probability that female 5 will be affected by the trait What is the probability that female 7 will be affected by the trait What is the probability that male 8 will be affected by the trait What is the probability that male 9 will be affected by the trait Name b 20 pts Now say that female 1 is affected by two different rare recessive X linked traits that are 10 cM apart we will refer to them as trait 1 and trait 2 Male 2 does not exhibit either trait Assume that individuals 3 and 6 neither have nor are carriers of either trait What is the probability that male 4 will be affected by both trait 1 and trait 2 What is the probability that male 8 will be affected by both trait 1 and trait 2 What is the probability that male 9 will be affected by trait 1 only What is the probability that male 9 will be affected by both trait 1 and trait 2 What is the probability that male 9 will be affected by neither trait 1 nor trait 2 Name 3 Consider two recessive Drosophila mutants that are on the same autosome curly wings cr and humpback hb 1 A wild type female is crossed to a curly winged humpbacked male to produce F1 flies that all look normal An F1 female is then crossed to a curly winged humpbacked male and 100 progeny from this cross are examined Phenotype wildtype curly wings humpback curly wings humpback Number 43 11 9 37 a 10 pts What is the distance between the cr and the hb 1 mutations in cM Next you isolate a second recessive humpback mutation hb 2 A female from a true breeding hb 2 strain is crossed to a male from a true breeding cr hb 1 strain An F1 female from this cross is then crossed to a male from a true breeding cr hb 1 strain and 500 progeny are examined Phenotype curly wings humpback curly wings humpback Number 5 240 255 b 10 pts What is the distance between the hb 1 and hb 2 mutations in cM Name c 10 pts Draw a genetic map showing the relative order of the cr hb 1 and hb 2 mutations as well as the distances that you have determined 7 03 Exam 1 Section TA Exam starts at 11 05 and ends at 11 55 There are seven pages including this cover page Please write your name on each page Also Look over the entire exam so you don t spend too much time on hard questions leaving easy questions unanswered Check your answer s to make sure that they make sense To help us give partial credit show your work and state any assumptions that you make Question 1 35 points Question 2 35 points Question 3 30 points Name 1 t t a4 pts Wild type yeast form white colonies Youhave isolated two mutants that make red colonies that you call red1 and red2 When a redlmutant is mated to a red2 mutant of the oppos ite mating type the esulting diploid makes white colonies W hatdoes this observation tell us about redland red2 b 9 pts When the diploids from part a are sporuiated are found Type I have 4 red colonies three types of tetrads Type tl have 1 white and 3 red colonies Type l J have 2 white and 2 red colonies Classify each tetrad type as PD NPD or T Tvoel TypeIt TvoeIII c 10 pts When the number of each tetrad type is tallied you find that the cross produces 30 Type I tetrads 16 Type 11tetrads and 4 Type III tetrads Are the red1 and red2 mutations iinked If so how far apart are they in cM A Name d 12 pts One of the Type II tetrads from above is selected for fu her analysis and you designate the four spore clones a b c and d Clone a is white whereas clones b c and d are red Each clone is mated to either redlmutant or a red2 mutant j Clone a white and the color of the esulting diploid is noted x red1 white diploid x red2 white diploid x red1 red diploid x red2 white diploid x red1 red diploid x red2 red diploid x red1 white diploid x red2 red diploid Clone b red Clone c red …
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