a sex chromosome of humans and most mammals that determines femaleness when paired with another X chromosome and that occurs singly in males.
When X Always = 10
Roman numerals are a collection of symbols that make up the number system that was used by the ancient Romans. Today, Roman numerals are more commonly used in titles, to number parts of works, in music theory, and on clock faces. Where do you see Roman numerals most often? The Symbols The Roman numeral system uses only seven symbols: I, V, X, L, C, D, …
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Compare Y chromosome.
Origin of X chromosome
First recorded in 1910–15
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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
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.
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.