In humans,XO individuals are females with Turner syndrome and XXY individuals are males with Klinefelter syndrome.Red-green colour blindness is caused by an X-linked recessive allele.Suppose a colour-blind man and a normal woman with no family history of colour blindness married and had a daughter who was colour-blind and had Turner syndrome.Which event could have given rise to this offspring?

Question

Quizplus · Accepted Answer

The daughter has Turner syndrome, which is caused by the absence of one X chromosome. This can only occur if the daughter inherited a single X chromosome from her mother, indicating that the mother's X chromosome did not separate properly during either meiosis I or meiosis II. Additionally, the daughter is colour-blind, which suggests that she inherited the X chromosome with the recessive allele from her father. Therefore, nondisjunction in the mother at either meiosis I or meiosis II is the best explanation for the daughter's condition.

In Humans,XO Individuals Are Females with Turner Syndrome and XXY