In cattle, the hornlessness gene dominates the horniness gene. What result can be expected

In cattle, the hornlessness gene dominates the horniness gene. What result can be expected from a heterozygous bull with gotozygous hornless cows? Can a hornless baby be born from a hornless cow and bull?

Let’s designate the gene that causes the hornlessness of cattle as B, then the gene that leads to the development of horns in cattle will be b.

The bull, according to the condition, is heterozygous: we will write it, according to the designations as BB, which will correspond to the absence of horns in the bull phenotype. Such a bull produces sperm B and b.

Homozygous hornless cows will be BB, they produce the same type B.

The offspring from the crossing of the described bull and cow will look like:

50% of calves – BB: hornless;

50% of calves are Bb, hornless.

Horned bulls and cows will be written as bb, since the homozygosity of their genotypes is an indispensable condition for the development of horns, which are indicated in the condition by a recessive trait. Such cows and bulls produce the same type of sex cells – b. In their offspring, all calves will be bb, which will correspond to the presence of horns.

Answer: 1. all calves will be hornless, with 50% homo-, 50% heterozygous for the hornless gene; 2. a hornless calf cannot be born from a horned bull and cow.