Computer graphics representation of part of the DNA (deoxyribonucleic acid) molecule, the genetic material of most organisms, showing its double helix structure. DNA is comprised of two strands of nucleotides linked together in single file. A nucleotide contains the sugar deoxyribose, a phosphate group & one of four organic bases (in blue): thymine, adenine, cytosine, & guanine. The former two pair only with each other as do the latter. The two nucleotide strands are knitted together through base-pairing by hydrogen bonding across adjacent nucleotides and coiled into a helix. Genetic information is determined by the sequence of base pairs along the molecule.