An inactivated X chromosome that appears as a small, black dot in the cells of genetic females, distinguishing them from male cells.

A highly condensed mass of chromatin found in the cell nuclei of normal female somatic cells, but not in the cell nuclei of normal male somatic cells. The body represents a condensed X chromosome.

A single condensed X chromosome. The Barr body is found in the nuclei of female somatic cells.

a condensed, deactivated X chromosome found in some cells of mammals.