Molecular biology sometimes abbreviated Bio mol or BM is a scientific discipline at the crossroads of genetics, biochemistry and physics whose object is the understanding of the mechanisms of functioning of the cell at the molecular level which allow the conservation and perpetuation of the living structure at the genotype level. The term Bio mol used for the first time in 1938 by Warren Weaver, also designates all the techniques of manipulation of nucleic acids (DNA, RNA), also called genetic engineering techniques. For this, the techniques of studying and modifying genes and their expression are an integral part of molecular biology. Molecular biology is a scientific discipline that describes the way in which genetic information is conserved, transmitted and expressed.