Help please!
Color blindness is a recessive sex-linked human trait. If a color-blind father
and a mother with normal color vision have a color-blind son, what must be
the mother's genotype?
O A. XNY
ОВ. XNXN
O c. XnYn
OD. XNXn

Cattle with brown fur and cattle with white fur will produce a reddish roan calf . when examined closely, the calf show about an even number of brown hairs and white hairs that give a reddish appearance when viewed from far away. the fact that both the brown fur allele and the white fur allele are expressed equally in the offspring is an example of