Question

A geneticist crossed pure breeding black mice with pure breeding brown mice. All the 992 mice in the F1 generation had black coats. When these mice were crossed, they yielded 961 black coated mice and 317 brown coated mice. How could you account for the ratio of black coated to brown coated mice in the F2 generation? Select all that apply. A. The F1 male produced two kinds of sperm, half carrying an allele for black coat color, and half carrying an allele for brown coat color. B. The F1 female produced two kinds of eggs, half carrying an allele for black coat color, and half carrying an allele for brown coat color. C. An approximately three-to-one ratio of black to brown coated mice in F2 is accounted for by the black allele being dominant over the brown allele. D. The brown allele is not independent from the black allele and disappears in the F1 generation.

Answer 1

C. An approximately three-to-one ratio of black to brown coated mice in F2 is accounted for by the black allele being dominant over the brown allele

Step-by-step explanation:

Assuming the black genotype is BB and the brown genotype is bb.

At F1:

BB x bb = All Bb (black)

At F2:

Bb x Bb = BB (black), 2Bb (Black), bb (brown)

Th ratio of black to brown is 3:1

961 black : 317 brown is approximately 3:1.

Hence, the correct option is C.

An approximately three-to-one ratio of black to brown coated mice in F2 is accounted for by the black allele being dominant over the brown allele