chro·​mo·​some | \ ˈkrō-mə-ˌsōm, -ˌzōm\

Definition of chromosome

: any of the rod-shaped or threadlike DNA-containing structures of cellular organisms that are located in the nucleus of eukaryotes, are usually ring-shaped in prokaryotes (such as bacteria), and contain all or most of the genes of the organism also : the genetic material of a virus — compare chromatin

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Other Words from chromosome

chromosomal \ ˌkrō-​mə-​ˈsō-​məl , -​ˈzō-​ \ adjective
chromosomally \ ˌkrō-​mə-​ˈsō-​mə-​lē , -​ˈzō-​ \ adverb

Examples of chromosome in a Sentence

Recent Examples on the Web

The condition is caused by a DNA glitch in chromosome 15. Shelley Levitt, Woman's Day, "These 4 Inspirational Women Went to Great Lengths for Their Kids," 4 Dec. 2018 Terry Jo, who worked as a midwife, had suffered two miscarriages after the birth of her daughters, but the results of her amniocentesis and chromosome testing had come back normal. Shelley Levitt, Woman's Day, "These 4 Inspirational Women Went to Great Lengths for Their Kids," 4 Dec. 2018 These molecular interactions leave chemical marks on the chromosomes passed on to different lines of cells in the body, explaining why a brain cell cannot be simply reprogrammed into a kidney cell or vice versa. John Hawks, WSJ, "‘Lamarck’s Revenge’ Review: Inheriting the Wrong Ideas," 16 Aug. 2018 The chromosomes naturally swap DNA during meiosis, and during those exchanges the cell only allows HDR. Jon Cohen, Science | AAAS, "‘Gene drive’ passes first test in mammals, speeding up inheritance in mice," 10 July 2018 Standish Allen, a professor at the Virginia Institute of Marine Science, developed a triploid oyster (with extra chromosomes) from the Crassostrea virginica that was already found in Virginia's waters. Sam Dangremond, Town & Country, "Is the Southeastern U.S. the Hottest New Region for Oysters?," 29 Jan. 2016 Having a lot of chromosomes enables dinosaurs to shuffle their genes around much more than other types of animals. Christopher Carbone, Fox News, "Scientists may have uncovered what dinosaur DNA looks like," 28 Aug. 2018 But in almost all of these cases, the ancestry seems to have come from a single exchange of chromosomes many generations prior. John Timmer, Ars Technica, "DNA shows girl had one Neanderthal, one Denisovan parent," 22 Aug. 2018 Over time, these molecules will gradually exchange segments with chromosomes inherited from other individuals. Cyrus Farivar, Ars Technica, "GEDmatch, a tiny DNA analysis firm, was key for Golden State Killer case," 27 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'chromosome.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of chromosome

1889, in the meaning defined above

History and Etymology for chromosome

borrowed from German Chromosom, from chromo- chromo- + -som -some entry 3

Note: The term Chromosom was first suggested by the German anatomist Heinrich Wilhelm Gottfried von Waldeyer-Hartz in "Ueber Karyokinese und ihre Beziehungen zu den Befruchtungsvorgängen," Archiv für mikroskopische Anatomie, Band 23 (1888), p. 27: "In ester Linier möchte ich mir jedoch den Vorschlag erlauben, diejenigen Dinge, welche soeben mit Boveri als 'chromatische Elemente' bezeichnet wurden, an denen sich einer der wichtigsten Akten der Karyokinese, die Flemming'sche Längsteilung vollzieht, mit einem besonderen terminus technicus 'Chromosomen' zu belegen. Der Name 'primäre Schleifen' passt nicht, da wir bei weitem nicht immer eine Schleifenform für diese Dinge haben. 'Chromatische Elemente' ist zu lang. Andererseits sind sie so wichtig, dass ein besonderer kürzerer Name wünschenswerth erscheint. Plattne… gebraucht den Ausdruck 'Karyosomen'; da dieser aber zu sehr an Kernkörperchen erinnert, dürfte eine andere Bezeichnung vorzuziehen sein. Ist die von mir vorgeschlagene praktisch verwendbar, so wird sie sich wohl einbürgern, sonst möge sie bald der Vergessenheit anheimfallen." ("In the first place I must allow myself to suggest a new technical term, 'chromosomes,' for those things which have been designated by Boveri 'chromatic elements,' at which one of the most important acts of karyokinesis, Flemming's longitudinal splitting, is carried out. The name 'primary loops' is not suitable, since it is by no means the case that these things always have the form of a loop. 'Chromatic elements' is too long. On the other hand, they are so important that a special shorter name seems desirable. Plattner uses the expression 'karyosomes,' but as this too readily brings to mind nucleoli, another name is to be preferred. If the name I propose is serviceable, it will become customary, otherwise it will soon pass into oblivion.")

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20 Jan 2019

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The first known use of chromosome was in 1889

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More Definitions for chromosome



English Language Learners Definition of chromosome

: the part of a cell that contains the genes which control how an animal or plant grows and what it becomes


chro·​mo·​some | \ ˈkrō-mə-ˌsōm \

Kids Definition of chromosome

: one of the rod-shaped or threadlike structures of a cell nucleus that contain genes and divide when the cell divides


chro·​mo·​some | \ ˈkrō-mə-ˌsōm, -ˌzōm \

Medical Definition of chromosome

: any of the usually linear bodies of the cell nucleus of eukaryotic organisms, the usually circular bodies of prokaryotic organisms (as bacteria), or especially in some schools of molecular biology the genomes of DNA viruses (as bacteriophages) that take up basophilic stains and contain most or all of the genes of the organism both the chromosomes of cells and those of viruses can duplicate only in the complex environment of a living cell— J. D. Watson an episome, an element that may exist as a free circular plasmid, or that may become integrated into the bacterial chromosome as a linear sequence— Benjamin Lewin

Other Words from chromosome

chromosomal \ ˌkrō-​mə-​ˈsō-​məl, -​ˈzō-​ \ adjective
chromosomally \ -​mə-​lē \ adverb

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More from Merriam-Webster on chromosome

Spanish Central: Translation of chromosome

Nglish: Translation of chromosome for Spanish Speakers

Britannica English: Translation of chromosome for Arabic Speakers Encyclopedia article about chromosome

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a complex dispute or argument

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