Chromosomes are located in the nucleus of a cell. They are tightly coiled except during cell division when they elongate.


Human cells normally contain 46 chromosomes identified as 23 pairs; 22 pairs are autosomes (non-sex chromosomes) and one pair are the sex chromosomes.

Diagram adapted from "Understanding Genetic Testing," National Institutes of Health
Posted: 10-28-03

Related Terms: aneuploidy; autosomal; cytogenetics; derivative chromosome; homologous chromosomes; karyotype; polyploidy

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From: Illustrated Glossary

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