: 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
Recent Examples on the WebThe vast majority of cases are caused by having three copies of chromosome 21 instead of two. Simon Makin, Scientific American, 1 Sep. 2022 The condition, which occurs when someone is born with a third copy of chromosome 21, used to be called Mongolism — a name that is no longer used. Helen Branswell, STAT, 2 Aug. 2022 Their daughter Bailey was born with Trisomy 18, also known as Edwards syndrome, in which an extra chromosome (No. 18) is present and causes severe developmental delays and birth defects. Lori Riley, Hartford Courant, 13 May 2022 Genetic mutations in the HEXA gene on chromosome 15 disrupt the formation of the lipid metabolizing enzyme beta-hexosaminidase A, resulting in the toxic buildup of a fatty acid compound called GM2 ganglioside inside nerve cells. Gary Stix, Scientific American, 18 July 2022 Then, studies tracking families with multiple cases of endometriosis helped researchers zero in on a particular region of chromosome 7. Rachel Fritts, Science | AAAS, 25 Aug. 2021 For those in the dark, back in March, Keke shared that her unborn baby was diagnosed with trisomy 33, a genetic disorder that happens when a child has an extra 13th chromosome. Elizabeth Ayoola, Essence, 3 June 2022 These laws typically target Down syndrome, or trisomy 21, in which the presence of a third chromosome 21 can have a range of physical and mental effects, milder in some children than others. Sarah Zhang, The Atlantic, 20 May 2022 However, gaps remained in parts of the genome that could not be resolved with the technology of the time, called the bacterial artificial chromosome. Manasee Wagh, Popular Mechanics, 1 Apr. 2022 See More
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.")