There are two homozygous lines of Drosophila, one with red eyes and one with pur
ID: 3362471 • Letter: T
Question
There are two homozygous lines of Drosophila, one with red eyes and one with purple. Biologists have suggested that there is a single gene responsible for this phenotype, with the red eye dominant. If that is true, one would expect that a crossing of these two lines would produce F2 progeny with red to purple eyes in the ratio of 3:1. Assume that investigators have a group of F2 progeny and that 28 have red eyes and that 15 have purple. Test the hypothesis that the distribution of eye color in the F2 progeny points to the population of Drosophila where the ratio of red to purple eyes is 3:1 2. Provide a brief answer to this question: What would you conclude from this analysis? (one or two sentences will do)Explanation / Answer
here null hypothesis:Ho: F2 progeny follow 3:1 ratio of red and purple eyes.
alternate hypothesis: Ha:F2 progeny does not follow 3:1 ratio of red and purple eyes.
applying chi square goodness of fit test on above data:
for above degree of freedom =categories -1= 2-1= 1
for 1 degree of freedom and above test statsitic p value =0.1345
as p value is high we can not reject null hypothesis
we do not have sufficient evidence to conclude that F2 progeny does not follow 3:1 ratio of red and purple eyes.
observed Expected Chi square eye color Probability O E=total*p =(O-E)^2/E red 0.750 28.000 43*0.75=32.25 0.56 purple 0.250 15.000 43*0.25=10.75 1.68 1 43 43 2.2403