chromosome

American  

[kroh-muh-sohm] / ˈkroʊ məˌsoʊm /

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.

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chromosome British  

/ ˈkrəʊməˌsəʊm /

noun

1. 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

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chromosome Scientific  

/ 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.

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Other Word Forms

• chromosomal adjective
• chromosomally adverb
• interchromosomal adjective
• interchromosomally adverb
• nonchromosomal adjective

Etymology

Origin of chromosome

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

Compare meaning

How does chromosome compare to similar and commonly confused words? Explore the most common comparisons:

• chromosome vs. chromatid
• chromatin vs. chromosome
• plasmid vs. chromosome

Example Sentences

"While the direct evidence of physical advantage in transgender people is pretty strong, the evidence of advantage for those with DSD, even though they have a Y chromosome, is highly disputed."

From BBC • Mar. 31, 2026

The Y chromosome contains relatively few genes beyond those involved in male development, so its absence was not expected to affect overall health.

From Science Daily • Mar. 20, 2026

There are also signs that Y chromosome loss can directly influence cancer behavior.

From Science Daily • Mar. 20, 2026

In fact, some marsupials lose the Y early in development, and in mammals the chromosome has been shrinking for about 150 million years.

From Science Daily • Mar. 20, 2026

An immense amount of work on the subject of chromosome abnormalities is being done by workers in many countries.

From "Silent Spring" by Rachel Carson