All living organisms are composed of cells and cells that contain nucleus have information about the body in the form of genes. Gene is a singular part of DNA – deoxyribonucleic acid. More specifically DNA is a chain of molecules twisted in a strand that forms chromosome, structural unit of genetic material. Gene, formulated by DNA, determines genotype – complete genetic information carried by an organism even if not expressed. It could be a hair colour, eye colour or even hereditary disease. Genetic information is inherited and passed on from generation to generation.
One of the most successful science discoveries was genetic engineering. It provided an opportunity to replace unwanted genes from one organism to another in order to achieve characteristic that organism is lacking. The focus of genetic engineering is gene. Identifying the particular DNA sequence of a gene or an entire genome allowed scientists to find the genetic material that codes for a desired trait and then insert the new material into another organism genetic code. Transgenic organisms with foreign genes most often are referred to as genetically modified. Transferred gene continued to function as if it was in the cell from which it was taken. Therefore, plants, animals or microorganisms gain new properties that previously were not typical. Fast development of genetic engineering gave humanity a very powerful technology that allows us to change natural traits of plants, animals or even people.
Genetically modified organisms vary in genome size and structure, although the same principle of application is used in these steps: identifying and selecting desired trait or characteristic, isolating gene segment responsible for it, inserting the gene into a vector and adding it the target organism, this process is called transformation.