In some cattle, the genes for red hair and for white hair are codominant. Cattle with alleles for both red and white hair have both red and white hairs. This condition is referred to as roan. What is the probability, expressed as a fraction, of a red cow and a roan bull having a roan offspring?
A. 3/4
B. 4/4
C. 1/2
D. 1/4

Co-dominant genes are the condition in which both the alleles from the parents are expressed equally resulting in heterozygous offspring. Hence dominant and recessive genes are expressed together.

The probability of roan offspring is:

Option C.  

The probability can be expressed as:

See the attached image for the cross below.

According to the cross, 50% of offspring will have the gene for red hair and the other 50% will be roan.

Thus, 50% of offspring will be roan.

To learn more about co-dominant follow the link:

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C. 1/2

Explanation:

Please see the attached Punnett square and probability.

1/2 = 2/4