When cattle with solid white coats (W) are mated to cattle with solid red coats (R), the offspring are roan (WR).

meaning they have coats containing both white and red hairs. The roan coat is an example of codominance.

A farmer mates two roan cattle.

What is the chance that their offspring will also be roan?

1/2 or 50%

Explanation:

The question involves a single gene coding for coat color in cattle. According to the question, the allele for red coat (R) is codominant to the allele for white coat (W). This means that neither of the two alleles are dominant nor recessive over one another, hence, they are both phenotypically expressed in their hybrid offspring (Roan coat, WR).

In a cross between two roan cattle (WR), each cattle will produce gametes with W and R alleles. Using these gametes in a punnet square (see attached image), a total of four possible offsprings will be produced with genotypes: RR, WR, WR, and WW.

RR (1/4) : Red coat

WR (1/2 or 2/4) : Roan coat

WW (1/4) : White coat

Based on this, the probability of producing an offspring that will be roan from the cross between two roan cattles is 2/4 equivalent to 1/2.