A human embryo is produced by the fusion of two gametes that have a normal complement of sex chromosomes. This individual develops into an adult and is diagnosed with Turner syndrome. How can this be?
A) An X chromosome was lost soon after fertilization, leading to a mosaic individual with a mixture of XX and XO cells.
B) Nondisjunction produced a gamete that lacked any sex chromosome. This gamete was fertilized, which resulted in the individual with Turner syndrome.
C) This individual is a gynandromorph with a mixture of both male and female characteristics.
D) The embryo was exposed to colchicine soon after fertilization, which produced a polyploidy individual. Dosage compensation caused an imbalance between autosomal and X chromosome gene expression.
E) A nonreciprocal translocation between the X chromosome and an autosome resulted in the loss of one of the X chromosomes.

Question

Quizplus · Accepted Answer

Turner syndrome can result from mosaicism, where some cells lose an X chromosome after fertilization, leading to a mixture of XX and XO cells.

A Human Embryo Is Produced by the Fusion of Two