base pair

one of the pairs of chemical bases joined by hydrogen bonds that connect the complementary strands of a DNA molecule or of an RNA molecule that has two strands; the base pairs are adenine with thymine and guanine with cytosine in DNA and adenine with uracil and guanine with cytosine in RNA

• nucleotide — a phosphoric ester of a nucleoside; the basic structural unit of nucleic acids (DNA or RNA)

• deoxyribonucleic acid, desoxyribonucleic acid, DNA — a nucleic acid found in the nucleus of a cell and consisting of a polymer formed from nucleotides and shaped like a double helix; associated with the transmission of genetic information