An organism that has been subjected to such genetic manipulation is referred to as a genetically modified organism.
Genetic modification involves the altering of the DNA code in a cell that is artificially grown in a laboratory before being reinserted into the same organism or an unrelated organism. The totality of genetic information that is present within the DNA of an organism is called genome, and this information is coded in such a way that it can be understood by all other living species. According to this coding system, four nucleotides are required to provide instructions to a cell on how it is to make any protein. (Steinbrecher, 1998).
Nucleotides are DNA units whose names are listed as letters – A, C, G and T. The arrangement of these in three letter words is equivalent to the code for specific amino acids. Within each gene, there are also regulatory elements which function as flags to control gene activity. Each gene also has an information block, which prevents gene activity from moving in an unusual direction. As a result, gene regulation is specific to the context of its environment.(Steinbrecher, 1998).
The process of genetically modifying an organism, which transports a gene from one organism into another, must also provide a means to circumvent the information block with cells of each organism, in order to provide recognizable flags or control sequences, which the other organism will recognize and accept. This is accomplished through the use of viruses, which are able to integrate their own DNA information into a host cell and cause it to multiply. This occurs due to the presence of powerful promoters in the viral cells that force the host cell to read viral genes and produce viral proteins, thereby producing construct or combined genes that can be used to produce desired changes in an organism (Steinbrecher, 1998).