: the first genetically modified animal to be sold as a pet.]]A Genetically modified organism (GMO) or genetically engineered organism (GEO) is an organism whose genetic material has been altered using genetic engineering techniques. These techniques are generally known as recombinant DNA technology. With recombinant DNA technology, DNA molecules from different sources are combined in vitro into one molecule to create a new gene. This DNA is then transferred into an organism and causes the expression of modified or novel traits. History The general principle of producing a GMO is to add genetic material into an organism's genome to generate new trait - Genetic engineering - was made possible through a series of scientific advances including the discovery of DNA and the creation of the first recombinant bacteria in 1973, i.e., E .coli expressing a salmonella gene.Cohen, S., Chang, A., Boyer, H. & Helling, R.