Triple X syndrome, or trisomy X, occurs when a female has an extra X chromosome in each of her cells. This results when the mother's reproductive cells divide improperly, and two X chromosome are moved into one gamete. When that gamete is fertilized and the father's DNA and X chromosome are combined with the mother's, that gives the cell three X chromosomes instead of two.

Triple X syndrome occurs because of _______.

Question

Triple X syndrome, or trisomy X, occurs when a female has an extra X chromosome in each of her cells. This results when the mother's reproductive cells divide improperly, and two X chromosome are moved into one gamete. When that gamete is fertilized and the father's DNA and X chromosome are combined with the mother's, that gives the cell three X chromosomes instead of two.

Triple X syndrome occurs because of _______.

anonymous · Answer

mutation I think.
Do you have answer choices?

aaronq · Answer

"This results when the mother's reproductive cells $\sf \color{red}{divide~ improperly}$, and two X chromosome are moved into one gamete." This is called "non-disjunction", because the chromosomes don't separate as they should. http://ghr.nlm.nih.gov/condition/triple-x-syndrome