The genetic modification of corn is based on incorporating the gene that produces a toxin similar to that produced by the bacterium Bacillus thuringiensis, a biological pesticide used by many farmers for several generations, is a rod-shaped bacterium and flagella (a kind of movable appendix) on the entire surface. This bacteria present in the soil, when breeding generates a protein crystal toxic to insects, who inadvertently ingest it, when dragged by different surfaces. Bt corn is a type of transgenic corn that produces a protein of bacterial origin. The Cry protein, produced naturally by Bacillus thuringiensis, is toxic to the larvae of stem borer insects that die by eating leaves or stems of Bt corn.