• DNA molecules consist of two strands twisted into a double helix. Each strand is made up of nucleotides each of which possesses one of 4 types of base (A, T, C or G)
  • A always pairs with T; C always pairs with G
  • The sequence of bases in the nucleotides enable the DNA to store information.
  • DNA replicates by a semi-conservative mechanism, which means that half of each new molecule comes from the original molecule.