Question

If you cross a roan cow with a roan bull, what percentage of the progeny would you expect to be roan?

• A. 10%
• B. 25%
• C. 50%
• D. 75%

Answer 1

The correct option is C 50%

Roan coat colour in shorthorn cattle is a co-dominant trait in which the roan cattle are heterozygous for the coat colour gene (WR).
When roan cattle are crossed,
$\begin{array}{ccc}& \text{W}& \text{R}\\ \text{W}& \text{WW}& \text{WR}\\ & \text{(White coat)}& \text{(Roan coat)}\\ \text{R}& \text{WR}& \text{RR}\\ & \text{(Roan coat)}& \text{(Red coat)}\end{array}$
50% of the progeny would be of roan coat colour (WR)