Black and white coloration in cows is dominant to brown and white. Black and white cows were crossed over several years and the following offspring were produced: 8 black and white and 3 brown and white.

What is the MOST probable genotype of each parent?
A)
BB X BB
B)
BB x bb
C)
Bb x Bb
D)
Bb x bb

Respuesta :

The answer is C) Bb x Bb

B - the allele for black and white coloration
b - the allele for brown and white coloration

There are in total 11 offspring (8 black and white and 3 brown and white),
In a monohybrid cross when both parents are heterozygous (Bb), the phenotype ratio is 3:1. We have ratio 8:3.

The ideal ratio would be 9:3 because it is the same as 3:1.
Therefore, the parents Bb and Bb will have 
8 black and white and 3 brown and white with the ration 8:3 ≈ 9:3 = 3:1