The theory of DNA double helix structure was proposed by American biologist Watson and British physicist Crick. Watson and Crick used the method of constructing physical models to study the structure of DNA. In 1957, Crick proposed the central dogma: genetic information can flow from DNA to DNA, that is, the replication of DNA; genetic information can flow from DNA to RNA, and then to proteins, that is, the transcription and translation of genetic information. Later, the central dogma was supplemented by two pathways for the flow of genetic information from RNA to RNA and from RNA to DNA.

Double helix structure characteristics:

The backbone is composed of deoxyribose and phosphate groups alternately connected through ester bonds. There are two main chains, which are "twisted" and rotate in a right-hand direction around a coaxial center. They are parallel to each other and move in opposite directions to form a double helix configuration. The main chain is outside the helix, which explains the hydrophilicity of the main chain composed of sugar and phosphate. On the outside of DNA is a backbone composed of alternately linked deoxyribose and phosphate sugars. The so-called double helix refers to the shape of the two main chains.