A recessive allele t is responsible for a condition called distonia. A man who has this condition marries a woman who doesn't. One of their four children has the condition. What are the possible genotypes of the man and the woman? (Hint: To help you answer this question, create a Punnett square for each possibility.)
a. Both parents are TT.
b. The father is tt; the mother is Tt.
c. The father is Tt; the mother is TT.
d. The father is tt; the mother is TT.