DNA, or deoxyribonucleic acid, is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses. DNA is the hereditary material in humans and almost all other organisms.
The structure of DNA was first described by James Watson and Francis Crick in 1953. The famous double-helix model consists of two strands that coil around each other to form a spiral shape, looking a bit like a twisted ladder.
Chromosomes, found in the nucleus of cells, contain the genetic material. Chromosomes come in pairs, with each of our parents contributing one from each pair. Here's a fun fact: Humans have 23 pairs of chromosomes!
