Question

The Punnett square shows a cross between a homozygous dominant genotype for hair color and a heterozygous genotype for hair color.

W W times W W.
W W.
W; W W, W W.
W; W W, W W.

Which conclusion can be drawn from the Punnett square above?

A
The parents will have four offspring.
B
Two of the offspring will be homozygous recessive.
C
Only two of the offspring will have the same hair color.
D
All of the offspring will have the same hair color.

Answer 1

D

Crossing WW (homozygous dominant) with Ww (heterozygous) yields offspring genotypes WW and Ww only (50% each). All carry at least one dominant W, so all show the same (dominant) hair color.