X-Chromosome

The sex chromosome found twice in normal females and once, along with a Y chromosome, in normal males. The complete chromosome complement (consisting of 46 chromosomes, including the 2 sex chromosomes) is thus conventionally written as "46,XX" for chromosomally normal females and "46,XY" for chromosomally normal males. The X chromosome not only determines gender but also carries the genetic code for many essential functions in both males and females.