Two Fast Whippets are Bred

Question

Two fast whippets are bred.What is the likelihood that their puppies will "bully"?
A) 33%
B) 50%
C) 25%
D) 0%
E) 100%

Accepted Answer

The "bully" phenotype in whippets is caused by a homozygous recessive mutation. If both parents are fast whippets, they are likely heterozygous carriers of the mutation. The probability of two heterozygous carriers producing a homozygous recessive offspring (bully) is 25%.