chromosomes

1. The small bodies in the nucleus of a cell that carry the chemical “instructions” for reproduction of the cell. They consist of strands of DNA wrapped in a double helix around a core of proteins. Each species of plant or animal has a characteristic number of chromosomes. For human beings, for example, it is forty-six.

In humans, sex is determined by two chromosomes: an X-chromosome, which is female, and a Y-chromosome, which is male. (See sex chromosomes.)

Example Sentences

Their research centers on TERRA, an RNA molecule that helps maintain the ends of chromosomes -- the regions of DNA that support cell stability and overall health.

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Having a pair of X chromosomes may shield females from harmful mutations and extend their lifespan.

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Before a cell can split into two, it must first copy all of its chromosomes so each new cell inherits a complete set of genetic material.

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A new review suggests that vitamin D supplements may help protect the ends of our chromosomes, known as telomeres, which play a vital role in slowing the aging process.

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Researchers suspected that the mutation causing the condition was somewhere on the X chromosome, because females, which have two X chromosomes, are less affected.

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