The American Heritage® Dictionary of the English Language, 4th Edition
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.
n. A unit of heredity; a segment of DNA or RNA that is transmitted from one generation to the next, and that carries genetic information such as the sequence of amino acids for a protein.
Word Usage
"$found = 1; last; die "Did not find gene $gene in $root. txt" unless $found = 1;"