In dogs, black coat (A) dominates over brown, and short coat (B) over long coat.

In dogs, black coat (A) dominates over brown, and short coat (B) over long coat. Homozygous dogs were crossed: black short-haired with brown long-haired. The resulting hybrids were then crossed among themselves and received 80 puppies. A .. How many gamete types are formed in F1 hybrids? B. How many different genotypes should F2 puppies have?

According to the designations introduced in the problem statement, we will write down homozygous black short-haired dogs as AABB. Such dogs produce AB germ cells.

Brown long-haired dogs will be recorded as aavb, because homozygosity is a prerequisite for the phenotypic realization of these traits. These dogs produce the sex cells of the ab.

All F1 offspring from the crossing of the described individuals will be AaBb: puppies with black short hair. These individuals will subsequently produce sex cells  аb, АВ, аВ and Аb.

The offspring from crossing such dogs with each other will be represented by the following options:

puppies with short black hair (AABB, 2AaBB, 2AABb, 4AaBb);

puppies with short black hair (2Aab, AAbb);

puppies with short black hair (aaBB, 2aaBb);

puppies with short black hair (aabb).

In F1 hybrids, 4 types of gametes are formed.

F2 produced puppies with 16 different genotypes.