A woman has a rare abnormality of the eyelids called ptosis, which prevents her from opening her eyes completely. This condition is caused by a dominant allele, P. The woman’s father had ptosis, but her mother had normal eyelids. Her father’s mother had normal eyelids.
(a) What are the genotypes of the woman, her father, and her mother?
(b) What proportion of the woman’s children will have ptosis if she marries a man with normal eyelids?