chromosome

[ kroh-muh-sohm ]

noun

, Genetics.

1. any of several threadlike bodies, consisting of chromatin, that carry the genes in a linear order: the human species has 23 pairs, designated 1 to 22 in order of decreasing size and X and Y for the sex-determining chromosomes. X chromosome ( def ), Y chromosome ( def ).

chromosome

/ ˈkrəʊməˌsəʊm /

noun

1. See homologous chromosomes
   any of the microscopic rod-shaped structures that appear in a cell nucleus during cell division, consisting of nucleoprotein arranged into units (genes) that are responsible for the transmission of hereditary characteristics See also homologous chromosomes

chromosome

/ krō′mə-sōm′ /

1. A structure in all living cells that consists of a single molecule of DNA bonded to various proteins and that carries the genes determining heredity. In all eukaryotic cells, the chromosomes occur as threadlike strands in the nucleus. During cell reproduction, these strands coil up and condense into much thicker structures that are easily viewed under a microscope. Chromosomes occur in pairs in all of the cells of eukaryotes except the reproductive cells, which have one of each chromosome, and some red blood cells (such as those of mammals) that expel their nuclei. In bacterial cells and other prokaryotes, which have no nucleus, the chromosome is a circular strand of DNA located in the cytoplasm.

Derived Forms

• ˌchromoˈsomally, adverb
• ˌchromoˈsomal, adjective

Other Words From

• chro·mo·so·mal [kroh-m, uh, -, soh, -m, uh, l], adjective
• chro·mo·so·mal·ly adverb
• in·ter·chro·mo·so·mal adjective
• in·ter·chro·mo·so·mal·ly adverb
• non·chro·mo·so·mal adjective

Word History and Origins

Origin of chromosome¹

First recorded in 1885–90; chromo- + -some ³

Example Sentences

He named chromosomes in 1888, before their exact nature was well-known.

From Science News

The scientists were especially interested in their telomeres—protective DNA sequences at the ends of chromosomes that act a bit like the caps on the ends of shoelaces.

From Popular-Science

Kelly experienced changes in his gut microbiome, his cognitive abilities slowed down, certain genes would turn off and on, and his chromosomes experienced structural changes.

From MIT Technology Review

In a study published last month, researchers at the Massachusetts Institute of Technology tracked an important part of the memory-making process at the molecular scale in engram cells’ chromosomes.

From Quanta Magazine

Each of Hsal’s cells carries 25 copies of its chromosome, which fragment and reassemble after a high radiation dosage.

From Nautilus

And yet they proved to have the same virus fossils in the exact same chromosome amid billions of possibilities.

From The Daily Beast

Carried distinctly through men, the Y chromosome only gives a portion of the entire mitochondrial DNA.

From The Daily Beast

It's not delirium tremors and chromosome breakage and only a small number of users would be seriously harmed.

From The Daily Beast

Once it was shown that women can have a single X chromosome (just as men can have two of them) that was abandoned as well.

From The Daily Beast

What does it mean, really, if your 14-week-old fetus has a deletion on chromosome 12?

From The Daily Beast

This X chromosome has also the factor for the development of red-eye pigment.

From Project Gutenberg

The accessory chromosome has been now observed in most of the great divisions of insects, except, as it happens, Lepidoptera.

From Project Gutenberg

Montgomery afterward showed that Henkings nucleolus was an accessory chromosome.

From Project Gutenberg

The chromosome situation in Protenor is a somewhat extreme case, inasmuch as one X chromosome is entirely lacking in the male.

From Project Gutenberg

On the basis of the chromosome theory the following explanation could be given of this numerical relation.

From Project Gutenberg