Now, because nondisjunction took place within this second haploid cell, because this failed to form the proper connection. This entire pair of identical sister chromosomes basically moved to opposite side and none of those sex chromosomes move to the other side. And so eventually, when we form our two X cells from this particular cell, we form cell number one and cell number two. And these two cells, cell number one and cell number two are abnormal. They're called an applied. And that's because this one lacks a copy of a sex chromosome and this one has an extra copy one more than it should.