18. A particular breed of dog can have long hair or short hair. When true-breeding long-haired animals were crossed to true-bree
ding short-haired animals, the offspring all had long hair. The F2 generation consisted of a 3:1 ratio of long- to short-haired animals. A second gene affects the texture of the hair. The two variants are wiry hair and straight hair. F1 offspring from a cross of these two varieties all had wiry hair, and F2 offspring showed a 3:1 ratio of wiry- to straight-haired puppies. Recently, a breeder of the short-, wiry-haired dogs discovered a female puppy that was albino. Similarly, another breeder of the long-, straight-haired dogs found a male puppy that was albino. The albino trait is due to a recessive allele. The two breeders got together and mated the two dogs. Surprisingly, all the puppies in the litter had black hair. How would you explain this result
