In dogs, black coat color (B) is dominant over brown (b), and solid coat color (S) is dominant over white spotted coat (s). A cross between a black, solid female and a black, solid male produces only puppies with black, solid coats. This same female was then mated with a brown, spotted male.
-Half of the offspring from this cross were black and solid, and half of the offspring were black and spotted. What is the genotype of the female?
A) BBSS
B) BbSS
C) BBSs
D) BbSs
E) bbss

Question

In dogs, black coat color (B) is dominant over brown (b), and solid coat color (S) is dominant over white spotted coat (s). A cross between a black, solid female and a black, solid male produces only puppies with black, solid coats. This same female was then mated with a brown, spotted male. 
-Half of the offspring from this cross were black and solid, and half of the offspring were black and spotted. What is the genotype of the female?
A) BBSS
B) BbSS
C) BBSs
D) BbSs
E) bbss

Quizplus · Accepted Answer

The female must be heterozygous for the spotted trait (Ss) to produce both solid and spotted offspring, and homozygous for the black trait (BB) to produce only black offspring.

In Dogs, Black Coat Color (B) Is Dominant Over Brown