The reason that missing an X chromosome and having an extra X chromosome do NOT cause more harm than they do is best explained by the
A)inactivation of any X beyond the first as a Barr body.
B)presence of genes on the Y chromosome that determine maleness.
C)presence of genes on the X chromosomes that determine femaleness.
D)loss of a sex chromosome in normal cells as embryo development occurs.
E)a higher level of gene-repair enzyme activity on sex chromosomes.

Question

Quizplus · Accepted Answer

Inactivation of any X beyond the first as a Barr body ensures that the genetic information from only one X chromosome is expressed in each cell, regardless of whether there is an extra X chromosome or a missing X chromosome. This mechanism helps to compensate for any genetic imbalance and prevent more harm from occurring.

The Reason That Missing an X Chromosome and Having an Extra