Cloning is a process by which identical organisms are produced. The genetic makeup of being close to being identical shows no genetic variation. A cloning vector can be defined as a fragment of DNA or a piece of DNA into which another foreign DNA fragment can be integrated for cloning. In nature, many organisms produce clones through asexual reproduction.

Trans genesis is the phenomena of production of transgenic animals that can be formed by adding one or more transgenes. Transgene is the foreign or modified gene that has been introduced into an organism. The term applied to organism that have been altered by introducing DNA molecule into them is known as transgenic. First example of transfer of foreign gene into an animal by recombinant DNA technology was the insertion of gene for growth hormone of inserted rat into mouse genome.

A gall is a tumour that contains masses of undifferentiated cell. Agrobacterium is the organism which causes the formation of crown gall disease in the plant. Agrobacterium tumefaciens is a plant bacterium that in fact the wound and stimulate the hosts and to multiply rapidly forming this crown gall. The T- DNA enters the plant cell and is inserted into a plant DNA as Transgene. This T-DNA is responsible for the formation of crown gall.

The electronic monitoring device in which any organism, microorganism in science system or other biological structure is used as an assay indicator to detect or to measure a chemical compound is known as biosensor. Biosensors are also useful to for automatic analysis of body fluids for metabolites, drugs and hormones.