A particular dog breed has black hair but comes in both long-haired and short-ha

Question

A particular dog breed has black hair but comes in both long-haired and short-haired varieties. When true-breeding long-haired animals are crossed to true-breeding short-haired animals, the F1 offspring all have long hair. When F1 dogs are bred to one another they produce an F2 generation with a 3:1 ratio of long- to short-haired offspring. A second trait involves the texture of the hair. The two variants are wiry hair and straight hair. F1 offspring from a cross of these two varieties all have wiry hair, and the F2 offspring showed a 3:1 ratio of wiry- to straight-haired puppies. Two breeders who specialized in dogs of different hair types (one specializing in short-, wiry-haired dogs and the other specializing in the long-, straight-haired dogs) each had some albino dogs in their colonies. They had heard that albinism in mammals was due to homozygosity for a recessive allele so they decided to breed their albinos together and come up with white dogs of various hair types. But when they crossed an albino short-, wiry-haired male from one colony with an albino long-, straight-haired female from the other colony, all the puppies in the litter had black hair. They then tried the reciprocal cross (albino short-, wiry-haired female and albino long-, straight-haired male) and again got only black puppies. Offer a sound genetic explanation for such surprising results.

Explanation / Answer

The albinism is caused due to deficiency in pigmentation. The pigmentation in dogs will be controlled by a different gene apart from the size and texture of its hair, hence we were unable to get proper results in case of albino dogs.

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