UT BIO 325L - Homework10Spring2014[KEY] (4 pages)

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Name Lab room day time TA name Crossing Over in Flies Data from the fly cross experiment were selected An associated excel file is supplied but fly counts are listed below in questions 1c and 4c The data is similar to that given for homework 9 but that assignment erroneously used last semester s data The calculated crossover frequencies have been supplied as a point of comparison Linked genes 1 Sepia Ebony have a published distance of 44 7 M U For that data run a Chisquare test to see if the data obtained fits with the published distance The following questions will walk you through that process a 1 5 point First determine expected frequencies of each individual progeny possibility based on the 44 7 M U distance Do this by showing a punnet square for frequencies Think about what M U s mean and how that affects gamete probabilities Assume that crossing over occurs equally between males and females Gamete probabilities are going to be 44 7 for each of the recombinants nonparental type 22 35 or 0 2235 and then of 55 3 27 65 or 0 2765 for the nonrecombinant parental type They just need to then fill out a square They don t need to have as many significant figures as indicated below I just copied it from excel Gamete Gamete Probability 0 2765 se e 0 2765 e 0 2235 se 0 2235 0 2765 0 0764522 5 0 0764522 5 0 0617977 5 0 0617977 5 se e 0 2765 0 0764522 5 0 0764522 5 0 0617977 5 0 0617977 5 e se 0 2235 0 2235 0 06179775 0 06179775 0 06179775 0 06179775 0 04995225 0 04995225 0 04995225 0 04995225 b 1 points From your punnet square calculate the expected frequencies of each phenotype based on a 44 7 M U distance They should add together the individual frequencies for each phenotype to get this answer Percentage Sepia and Wild type Ebony Sepia ebony 0 5764522 0 1735477 0 17354775 0 07645225 s 5 5 c 1 points Determine the expected number of flies of each category round to the nearest hundredth of a fly WT Observed Expected Ebony body 117 727 565 50 170 25 Sepia eye Sepia Ebony 66