What is the genetic engineering?

Image 3.1. Picture showing
how we can play with the
DNA.

Is an amount of techniques that allow you modify the characteristics of an alive organism through directed and controlled modification of its genome, adding, eliminating or modifiying some of its genes, that it is not other than a modification in the DNA of the organism all time oversight by humans who carry it out. 

Image 3.2. Picture showing how we can play
with the DNA.

Thus, among other applications, genetic engineering allows you to eliminate an undesirable characteristic as producing a toxine, annulling the corresponding gene. 

Also it allows you to introduce a new characteristic as an insect resistance, copying the corresponding gene resistant to this individual from a resistant specie and introducing it in the genome of the susceptible specie. 

As it exist an universality of the genetic code, genetic engineering can use the "information" in all organisms.