Learn more about the structure and synthesis of this remarkable molecule, and how genes in your DNA provide instructions for building proteins. the branch of genetics that focuses on the chemical structure and the functions, replication, and mutations of the molecules involved in the transmission of genetic information, namely DNA and RNA. Molecular Genetics Molecular genetics is the branch of genetics that investigates the chemical and physical nature of genes and the mechanisms by … molecular genetics. DNA serves as the genetic material for all living organisms.