Answer:
X-chromosome inactivation
Step-by-step explanation:
In mammals, females have two copies of X chromosomes while the males have one X and one Y chromosome as their sex chromosomes. The presence of two copies of the X chromosome in females means the presence of double the number of X-linked genes in them as compared to the males. However, during embryonic development, one of the two X chromosomes is inactivated in the cells of females.
The inactivated X chromosome is present as a Barr body in the nucleus. X chromosome inactivation is a random process and either paternal or maternal X chromosome can be inactivated. The process of inactivation of the X chromosome in females balances the dosage of X linked genes among males and females.