DNA (deoxyribonucleic acid) is the genetic material that contains the instructions for the development and function of all living things. It is a double-stranded, helical molecule made up of four nitrogen-containing bases (adenine, guanine, cytosine, and thymine) and a sugar-phosphate backbone. The order of the nitrogen bases determines the genetic code, which carries the instructions for the synthesis of proteins.

DNA replication is the process by which cells make a copy of their DNA before cell division, ensuring that the genetic information is passed on to the daughter cells. The process of transcription and translation then use the information encoded in DNA to synthesize proteins, which carry out a variety of functions in the cell and in the organism as a whole.

DNA is found in the nucleus of eukaryotic cells and in the cytoplasm of prokaryotic cells. In addition to its role in coding for proteins, DNA also plays a role in the regulation of gene expression, meaning that the genes present in DNA can be turned on or off to produce the proteins that are needed in a particular cell or at a particular time.