In English | En español
Questions About Cancer? 1-800-4-CANCER

NCI Dictionary of Cancer Terms

Page Options

  • Print This Page

Widget



base pair  listen  (bays payr)

  Molecules called nucleotides, on opposite strands of the DNA double helix, that form chemical bonds with one another. These chemical bonds act like rungs in a ladder and help hold the two strands of DNA together. There are four nucleotides, or bases, in DNA: adenine (A), cytosine (C), guanine (G), and thymine (T). These bases form specific pairs (A with T, and G with C).

More Information

Enlarge
DNA base pair; drawing shows double-stranded DNA with bonds between two pairs of  nitrogen-containing bases [adenine (A) and thymine (T), and cytosine (C) and guanine (G)].