gene amplification (thing)

1. The creation of extra, functional copies of genes in a cell or organism.
2. The duplication of an entire genome within a cell or organism.
3. A procedure applied to a bacterium that increases the proportion of plasmid DNA to bacterial DNA (some antibiotics have this effect).

From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.