Question

In racoons, a dark face is dominant over a bleached face. Several crosses were made between racoons that were heterozygous for a dark face and homozygous for a bleached face mask. What percentage of the offspring would be expected to have a dark face?

• A. 0%
• B. 50%
• C. 75%
• D. 100%

Answer 1

The correct option is B 50%

Let the allele responsible for dark face and bleached face in racoons be represented by D and d respectively. Let us assume that the male parent is heterozygous for a dark face and the female parent has a bleached face.

Genotypic ratio in $F_1$ generation:-
Dd : dd = 1 : 1

Phenotypic ratio in $F_1$ generation:-
Dark face : Bleached face = 1 : 1

$\Rightarrow$ Out of 2 racoons, no. of dark faced offspring = 1

$\Rightarrow$ Out of 100 racoons, no. of dark faced offspring $=\frac{1}{2}\times 100=50$

Hence, the percentage of offspring with dark face = 50%