A child is born with Turner's syndrome and she is red green color blind recessive X- linked).Her father is red green color blind as well and her mother is homozygous dominant for color sight.What had to happen in order for this child to be born with this chromosomal complement?
A)nondisjunction in either meiosis I or meiosis II of the father
B)nondisjunction in meiosis II of the mother
C)nondisjunction in meiosis II of the father
D)nondisjunction in meiosis I of the father
E)nondisjunction in either meiosis I or meiosis II of the mother

Question

Quizplus · Accepted Answer

Turner's syndrome occurs when one of the X chromosomes is missing or partially missing, which can result from nondisjunction during meiosis in the mother. Since the father cannot pass on Turner's syndrome through his Y chromosome, and the mother is homozygous dominant for color sight (indicating she has two X chromosomes), nondisjunction in the mother's gametes would lead to a child with Turner's syndrome. The red-green color blindness inherited from the father indicates that the single X chromosome the child received was the one carrying the color blindness allele.

A Child Is Born with Turner's Syndrome and She Is