In horses,there are four alleles at the A locus.Arranged in dominance sequence,they are A (wild),a b (bay),a c (brown),a d (black)
If you bred several bay mares whose sires were brown to a brown stallion whose sire was black,what are the genotypes of the parents; what type of offspring would be produced; and in what proportion?
A) a a a d x a c a d ; 1/2 brown, 1/2 black
B) a b a c x a c a d ; 1/2 bay, 1/2 brown
C) Aa b x a c a d ; 1/2 bay, 1/2 wild
D) Aa b x a c a d ; all wild
E) a d a b x a c a d ; all black

Question

In horses,there are four alleles at the A locus.Arranged in dominance sequence,they are A (wild),a b (bay),a c (brown),a d (black)
If you bred several bay mares whose sires were brown to a brown stallion whose sire was black,what are the genotypes of the parents; what type of offspring would be produced; and in what proportion?
A) a a a d x a c a d ; 1/2 brown, 1/2 black 
B) a b a c x a c a d ; 1/2 bay, 1/2 brown
C) Aa b x a c a d ; 1/2 bay, 1/2 wild
D) Aa b x a c a d ; all wild
E) a d a b x a c a d ; all black

Quizplus · Accepted Answer

Breeding a bay mare with a brown sire to a brown stallion with a black sire would result in offspring with genotypes of a^ba^c, a^ba^d, a^ca^c, and a^ca^d. This would result in 1/2 of the offspring being bay and 1/2 being brown, with no black offspring produced.

In Horses,there Are Four Alleles at the a Locus