Genetically modified organism:

It is the result of a laboratory process where genes from the DNA of one species are extracted and artificially forced into the genes of an unrelated plant or animal. The foreign genes may come from bacteria, viruses, insects, animal even human.

Benefits of genetically modified plants are following:

The plants produced through genetic engineering contain genes usually from an unrelated organism. Such genes are called transgenes and the plants having transgenes are called transgenic plants. There is a soil bacterium Bacillus thuringiensis which produces proteins to kill certain insects. These toxic proteins crystals are called insecticidal proteins also named as Bt toxin proteins. Bt toxin proteins exist as inactive protoxins but once an insect ingest the inactive toxin, it is converted into an active form of toxin. The activated toxin binds to the surface of midgut epithelia cells and create pores, which eventually leads to death of the insect.

Such specific Bt toxin genes are isolated from Bacillus thuringiensis and incorporated into several crops such as cotton. The choice of gene depends upon the crop and the targeted pest. Toxin is coded by a gene named Cry.