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
First recorded in 1910–15
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The fact that Neanderthal DNA is rare on the X chromosome does not, in itself, allow us to reconstruct Palaeolithic social organization or the sexual preferences of these populations.
From Science Daily ● Jul. 7, 2026
The team analyzed modern human DNA preserved in Neanderthals, and found an abundance on the X chromosome -- the mirror opposite of humans.
From Barron's ● Feb. 26, 2026
Researchers suspected that the mutation causing the condition was somewhere on the X chromosome, because females, which have two X chromosomes, are less affected.
From The Wall Street Journal ● Oct. 6, 2025
This tallies with the fact that the gene is carried on the X chromosome.
From BBC ● May 15, 2025
The other half of the males have white eyes, because the other half of the eggs had each a white-producing X chromosome.
From A Critique of the Theory of Evolution by Morgan, Thomas Hunt
As the researchers discovered, X-chromosome inactivation can lead to autoimmune disorders, but other factors can also cause these disorders -- which is why men sometimes develop them.
From Science Daily ● Feb. 1, 2024
Performing that so-called X-chromosome inactivation is a special type of RNA called Xist, pronounced like “exist.”
From Seattle Times ● Feb. 1, 2024
His team is studying the handful of X-chromosome genes now known to be more active in females than in males.
From Nature ● Feb. 17, 2015
The ABC bears, as they’re called, look outwardly like brown bears, but their mitochondrial DNA comes from polar bears, as does a portion of their X-chromosome.
From New York Times ● Aug. 14, 2014
But among the males, the odd chromosome, also known as the X-chromosome, can perforce go only into half of the sperm cells, leaving the others without it.
From The Glands Regulating Personality by Berman, Louis, M.D.
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
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