Molecular biology is a branch of biology that has been growing in importance since the 1940s. It developed out of the sciences of genetics and biochemistry. Genetics is the study of heredity, the process by which certain characteristics of an organism are handed down from parent to offspring. Biochemistry is the study of chemical compounds and processes in organisms. Molecular biologists seek to explain biological events by studying the molecules within cells. They are especially interested in the molecular basis of genetics and inheritance and the production of proteins. Proteins are large, complex molecules that are an essential part of all living cells.

Most molecular biologists are involved in research and development. Some conduct basic research to expand knowledge without the direct aim of benefiting humans. Others may conduct applied research, which is used to benefit humans directly. Applied research generally focuses on issues important to...