A genetically modified organism, or

A genetically modified organism, or GMO, is an organism that has had its DNA altered or modified in some way through genetic engineering.

In most cases, GMOs have been altered with DNA from another organism, be it a bacterium, plant, virus or animal; these organisms are sometimes referred to as "transgenic" organisms. A genefrom a spider that helps the arachnid produce silk, for example, could be inserted into the DNA of an ordinary goat.