Here's a breakdown:
* X chromosome: One of the sex chromosomes. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY).
* Inactive X: In females, one of the two X chromosomes is randomly inactivated during early development to ensure that females don't have twice the amount of X-linked gene products as males.
* Condensation: The inactive X chromosome becomes tightly packed and condensed, forming a small, dense structure.
* Barr body: The name given to this condensed, inactive X chromosome.
Barr bodies can be observed under a microscope in cells from females but not in cells from males. This observation is used in determining the genetic sex of an individual.
