In horses, black coat (B) is dominant over brown coat (b), and being a trotter (T) is dominant over being a pacer (t). A black horse who is a pacer is crossed with a brown horse who is a trotter. The offspring is a brown pacer. What is the genotype of the brown trotter parent?
A) BBTT
B) BbTt
C) Bbtt
D) bbTt
E) bbtt

Question

Quizplus · Accepted Answer

The brown trotter parent must carry the recessive allele for coat color (b) to produce a brown offspring and must have at least one dominant allele for trotting (T). Since the offspring is a pacer (tt), the brown trotter parent must also carry a recessive allele for pacing (t), making the genotype bbTt.

In Horses, Black Coat (B) Is Dominant Over Brown Coat