Question

multiple choice question
roan cattle have alleles for white colored hair (w) and red colored hair (r). these two alleles are codominant so that cattle with the genotype rw will have a coat that has both red and white patches, which is usually described as a roan coat. roan cattle that have the genotype rr have a pure red coat. roan cattle that have a genotype ww have a pure white coat. if two cattle with roan coats are mated, what are the possible outcomes of their offspring?

• 50% chance that offspring will have roan coats, 50% chance that offspring will have white coats
• 100% chance that offspring will have roan coats
• 50% chance that offspring will have roan coats, 25% chance that offspring will have white coats, 25% chance that offspring will have red coats
• 25% chance that offspring will have roan coats, 25% chance that offspring will have white coats, 50% chance that offspring will have red coats

Explanation:

Step1: Determine Parental Genotypes

Both parents are roan, so their genotype is \( RW \).

Step2: Set Up Punnett Square

The alleles from each parent are \( R \) and \( W \). The Punnett square for \( RW \times RW \) is:

	\( R \)	\( W \)
\( W \)	\( RW \)	\( WW \)

Step3: Calculate Genotype Ratios

• \( RR \): 1 out of 4 (25%)
• \( RW \): 2 out of 4 (50%)
• \( WW \): 1 out of 4 (25%)

Step4: Relate Genotypes to Phenotypes

• \( RR \): red coat (25%)
• \( RW \): roan coat (50%)
• \( WW \): white coat (25%)

Answer:

50% chance that offspring will have roan coats, 25% chance that offspring will have white coats, 25% chance that offspring will have red coats