Left-handedness (r) is recessive in humans and right-handedness is dominant (R).
Tracy, a left-handed woman, and whose mother and brother are also left-left handed,
marries Sa who is right-handed. Sam's mother is left-handed and his father and sister
are right-handed. What is the expected genotypic ratio of the children Sam and Tracy
might have?
ORr:2rr:ORR
1Rr:2rr:1RR
2Rr:2rr:ORR