Final answer:
X inactivation is a process that occurs in female mammals, including humans, during early development. It involves the condensation of one of the two X chromosomes in each cell into a dormant structure called a Barr body. The genes on the inactive X chromosome are not expressed, allowing females to compensate for their double genetic dose of X chromosome.
Step-by-step explanation:
X inactivation is a process that occurs in female mammals, including humans, during early development. It involves the condensation of one of the two X chromosomes in each cell into a dormant structure called a Barr body. The genes on the inactive X chromosome are not expressed, allowing females to compensate for their double genetic dose of X chromosome. The inactivation of the X chromosome is random in each cell, but once it occurs, all cells descended from that cell will have the same inactive X chromosome.