Question

if a red cow (homozygous dominant) is crossed with a white cow (homozygous dominant), what alleles will the offspring have?
rw
rw
rw
rw

Explanation:

Step1: Define alleles

Let R represent the dominant allele for red color (from the red cow which is homozygous dominant, so its genotype is RR). Let W represent the dominant allele for white color (from the white cow which is homozygous dominant, so its genotype is WW).

Step2: Determine offspring alleles

When RR (red cow) is crossed with WW (white cow), each parent can only pass on one type of allele. The red - cow passes on an R and the white - cow passes on a W. So the offspring will have the genotype RW.

Answer:

B. RW