Below is a Punnett square that shows a model of human inheritance
A
А
Аа
Aa
a
a
Аа
Аа
KEY: A = straight hair (dominant); a = curly hair (recessive)
Which of the following must be true about the parent whose
genes are aa?
a
The parent has straight hair
b The parent is dominant
The parent has curly hair
d The parent is capable of having AA offspring