In cattle, the horniness gene dominates over the horniness gene, and the roan coat color is formed

In cattle, the horniness gene dominates over the horniness gene, and the roan coat color is formed as an intermediate trait when crossing red and white animals. A heterozygous hornless roan bull was crossed with the same cow. Determine the likelihood of having calves that look like parents

Let’s designate the gene that causes the absence of horns in cows as B, then the gene responsible for their development will be b.

Let’s designate the gene for red wool in cows as C, then the gene for white wool will be c, and for roan cows – Cc.

According to the introduced designations, we will write down the genotypes of the parent individuals.

The hornless roan bull, according to the condition of the problem, is heterozygous, we will write it as ВbСс. Such a bull produces spermatozoa BC, bc, bC and Bc.

The genotype of the cow and the eggs it produces are similar to those described for the bull.

The offspring from crossing the data of a bull and a cow will look like this:

red hornless calves (2ВbСС, ВВСС);

roan hornless calves (2ВВСс, 4ВbСс);

roan horned calves (2bbСс);

red horned calves (bbcc);

white horned calves (bbcc);

white hornless calves (2Bbcc);

red horned calves (bbcc).

Roan hornless calves accounted for 6 to 16, or 37.5%.

Answer: The probability of giving birth to roan hornless calves in this bull and cow is 37.5%.