In your studies of the unusual ant species W. yuae you find two true breeding st
ID: 188922 • Letter: I
Question
In your studies of the unusual ant species W. yuae you find two true breeding strains. Strain 1 is yellow-skinned and has oval shaped abdomens. Strain 2 is blue-skinned with triangular abdomens. Crossing a strain 1 female with a strain 2 male results in the following:
All females are yellow-skinned with trianle shaped abdomens .........................
All males are yellow-skinned with oval shaped abdomens ................................
a. Please give the genotype of the F1s on the lines above.
b. What is the probability of obtaining a female with blue skin and a triangular abdomen from a cross of F1 males X F1 females?
Explanation / Answer
Let us denote strain 1 as YYtt (Yellow skinned Oval abdomen) and strain 2 as yyTT (blue skinned with triangular abdomen), yellow YY is dominant over blue yy and triangluar abdomen TT is dominant over oval abdomen tt.
Strain 1 female = XYtXYt x Strain 2 male = XyTO
a. F1 generation: Female : XYtXyT (Yellow skinned triangular abdomen)
Male : XYtO (Yellow skinned oval abdomen)
b. The probability of obtaining a female with blue skin and a trianglular abdomen from a cross of F1 males and F1 females is zero because the crossing will always transfer a set of dominant allele for the yellow skin in all females.