a sex chromosome of humans and most mammals that determines femaleness when paired with another X chromosome and that occurs singly in males.
What The “X” In “Xbox” Stands For?No letter in the English language gets around like X. The 24th letter of the alphabet shows up everywhere, from the popular Xbox to standing in for a signature on legal documents. It represents a chromosome, signifies the multiplication process, and marks “the spot” on treasure maps. Let’s explore just a few of the uses of this versatile letter. The story behind the X in Xbox …
Compare Y chromosome.
Origin of X chromosome
First recorded in 1910–15
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for x-chromosome
the sex chromosome that occurs in pairs in the diploid cells of the females of many animals, including humans, and as one of a pair with the Y-chromosome in those of malesCompare Y-chromosome
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Medicine definitions for x-chromosome
The sex chromosome associated with female characteristics, occurring paired in the female and singly in the male sex-chromosome pair.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Science definitions for x-chromosome
[ ĕks′krō′mə-sōm′ ]
The sex chromosome that in female mammals is paired with another X-chromosome and in males is paired with a Y-chromosome. Very few genes on the X-chromosome have counterparts on the Y-chromosome, and since males have only one X-chromosome, any gene present on it (even if the gene is recessive in females) is expressed in males. In females, one of the two X-chromosomes in each cell is deactivated. See more at sex chromosome. See note at sex.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.