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Genes

3 dictionary results for: genes

American Heritage Dictionary - Cite This Source - Share This

gene (jēn) Pronunciation Key
n. A hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic in an organism. Genes undergo mutation when their DNA sequence changes.

[German Gen, from gen-, begetting, in Greek words (such as genos, race, offspring); see genə- in Indo-European roots.]

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The American Heritage® Dictionary of the English Language, Fourth Edition
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The American Heritage Science Dictionary - Cite This Source - Share This

gene (jēn) Pronunciation Key
A segment of DNA, occupying a specific place on a chromosome, that is the basic unit of heredity. Genes act by directing the production of RNA, which determines the synthesis of proteins that make up living matter and are the catalysts of all cellular processes. The proteins that are determined by genetic DNA result in specific physical traits, such as the shape of a plant leaf, the coloration of an animal's coat, or the texture of a person's hair. Different forms of genes, called alleles, determine how these traits are expressed in a given individual. Humans are thought to have about 35,000 genes, while bacteria have between 500 and 6,000. See also dominant , recessive. See Note at Mendel.

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