What is the structure of DNA?

The structure of DNA is characterized as a double helix, which was first described by James Watson and Francis Crick in 1953. This structure consists of two long strands of nucleotides that coil around each other, resembling a twisted ladder. Each strand is composed of a sugar-phosphate backbone and nitrogenous bases that pair specifically—adenine pairs with thymine, and cytosine pairs with guanine.

The double helix formation allows for the stable storage of genetic information and its precise replication during cell division. The specific base pairing and the antiparallel nature of the strands are critical for the processes of DNA replication and transcription, ensuring genetic fidelity and proper expression of genes. This unique structure is fundamental to the function of DNA in heredity and biological processes.