In a Human,what is the Best Explanation for Being XX

Question

In a human,what is the best explanation for being XX and phenotypically male?
A) One of the X's is incomplete resembling a chromosome.
B) A small piece of the Y-chromosome, containing the SRY region, is inserted on the X-chromosome.
C) Both the X's have a mutation deleting the "female" forming genes.
D) There is a fragment of the Y-chromosome inserted on an autosomal chromosome.
E) The SRY gene has mutated.

Accepted Answer

The presence of the SRY region on the Y chromosome determines male development. In rare cases, a small piece of the Y-chromosome can be inserted onto the X-chromosome, resulting in a male individual with XX chromosomes. This insertion contains the SRY region, leading to male phenotypic expression.