Pair of nucleotide bases (A-T or G-C) that form the middle of the DNA molecule.
Observations by Erwin Chargaff that concentrations of the four nucleotide bases differ among species; and that, within a species, the concentrations of adenine and thymine are always about the same and the concentrations of cytosine and guanine are always about the same.
Double spiral shape of the DNA molecule.
DNA replication process where half of the parent DNA molecule is conserved in each of the two daughter DNA molecules.
Process of copying DNA prior to cell division.
Describes how DNA's structure and function was discovered.