sex chromosome

sex chromosome

noun

Definition of SEX CHROMOSOME

: a chromosome that is inherited differently in the two sexes, that is concerned directly with the inheritance of sex, and that is the seat of factors governing the inheritance of various sex-linked and sex-limited characters — compare x chromosome, y chromosome

First Known Use of SEX CHROMOSOME

1906

sex chromosome

noun    (Medical Dictionary)

Medical Definition of SEX CHROMOSOME

: a chromosome (as the X chromosome or the Y chromosome in humans) of a sexually reproducing eukaryotic organism that is directly concerned with the inheritance of sex, that contains the genes governing the inheritance of various sex-linked and sex-limited characters, and that is represented differently in the two sexes either by being present in one and not the other or by being present a different number of times in one sex compared to the other—called also heterochromosome

Illustration of SEX CHROMOSOME

sex chromosome

noun    (Concise Encyclopedia)

Either of a pair of chromosomes that determine whether an individual is male or female. The sex chromosomes of mammals are designated X and Y; in humans, they constitute one pair of the total 23 pairs of chromosomes. Individuals possessing two X chromosomes (XX) are female; those having one X and one Y chromosome (XY) are male. The X chromosome is larger and carries more genetic information than the Y. Traits controlled only by genes found on the X chromosome (e.g., hemophilia, red-green colour blindness) are said to be sex-linked. Sex-linked traits occur far more frequently in males than in females, since a male inheriting an allele for a recessive (see recessiveness) trait on the X chromosome lacks a corresponding allele on the Y chromosome that might counteract its effects. Several disorders are associated with an abnormal number of sex chromosomes, including Turner syndrome and Klinefelter syndrome.