Organisms that have genes from other species inserted into their genomes are called transgenic organisms. "Transgenic" refers to the introduction of a DNA sequence from other species by the artificial methods. This process of modification of the genomes of living organisms is called genetic engineering.
If the genes present in the reproductive cells are altered, the novel characteristics are passed to the next generation. If the genes in the somatic or vegetative cells are altered, the changes can affect that particular individual only. Transgenesis is the process in which a new trait is introduced into the organism that was not inherited through normal reproduction. Gene therapy is one of the applications of transgenesis.