DNA and the human body. Computer artwork of part of the molecule of DNA (deoxyribonucleic acid) with a standing anatomical human figure. DNA contains all the inherited instructions necessary to produce a human being. Atoms are depicted as balls and sticks and are colour-coded: carbon (white), hydrogen (pale blue), nitrogen (dark blue), oxygen (red) and phosphorous (yellow). The DNA molecule is composed of two strands of atoms twisted into a helical shape, with cross- linking bases between them that make up the genetic code in the form of genes. This drawing of the human muscle system is by Andreas Vesalius from his book: De Humani Corporis Fabrica (1543).