Why a double helix?
DNA is your cells' store of coded 'digital' information, which cells copy very nearly perfectly every time they divide. The pairing of the DNA bases in the middle of the two strands of the double helix (A with T, C with G) helps to keep this precious code intact. Each strand of DNA itself provides the pattern for building a new strand. When the cell needs to use or copy any of the information, the double helix 'unzips' to reveal this template.
