In the laboratory, a genetics student crossed flies with long wings to flies with mutant dumpy wings, which she believed
Posted: Thu Jun 09, 2022 1:55 pm
In the laboratory, a genetics student crossed flies with long
wings to flies with mutant dumpy wings, which she believed was a
recessive trait. In the F1, all flies had long wings. In the F2,
the following results were obtained: long-winged 792 dumpy-winged
208 The student tested the hypothesis that the dumpy wing mutation
is inherited as a recessive trait by performing a chi-square test
on the F2 data.
(a) If the student hypothesized that the dumpy mutation is
recessive, then what is the hypothesized EXPECTED RATIO in the F2
generation? Based on this ratio, what would be the expected
proportion for each type of fly?
(b) Now that you have an expected ratio and expected
proportions, show your chi-square calculations below. Use the
chi-square table from slide 13 of the Laboratory 2 Part 2 lecture
or in Chapter 3 of the textbook. Be sure to clearly state (1) the
calculated chi-square value, (2) the degrees of freedom, (3) the
probability associated with the calculated chi-square value, if the
probability is “off the table” then simply state if the probability
is smaller than (to the right) of 0.05. Finally, (4) state whether
you fail to reject or reject the null hypothesis (written out in a
full sentence)
(c) Do the results of the chi square test suggest that the dumpy
mutation is recessive, yes or no? Why?
wings to flies with mutant dumpy wings, which she believed was a
recessive trait. In the F1, all flies had long wings. In the F2,
the following results were obtained: long-winged 792 dumpy-winged
208 The student tested the hypothesis that the dumpy wing mutation
is inherited as a recessive trait by performing a chi-square test
on the F2 data.
(a) If the student hypothesized that the dumpy mutation is
recessive, then what is the hypothesized EXPECTED RATIO in the F2
generation? Based on this ratio, what would be the expected
proportion for each type of fly?
(b) Now that you have an expected ratio and expected
proportions, show your chi-square calculations below. Use the
chi-square table from slide 13 of the Laboratory 2 Part 2 lecture
or in Chapter 3 of the textbook. Be sure to clearly state (1) the
calculated chi-square value, (2) the degrees of freedom, (3) the
probability associated with the calculated chi-square value, if the
probability is “off the table” then simply state if the probability
is smaller than (to the right) of 0.05. Finally, (4) state whether
you fail to reject or reject the null hypothesis (written out in a
full sentence)
(c) Do the results of the chi square test suggest that the dumpy
mutation is recessive, yes or no? Why?