the world > life > biology > biological processes > genetic activity > [noun] > genetic information storage > change in structure of nucleotide pair (2)
Molecular Biology. A point mutation in a nucleic acid sequence in which one purine base replaces another, or one pyrimidine base replaces…
Molecular Biology. The occurrence in a nucleic acid of a purine in place of a pyrimidine or vice versa. Cf. transition, n. 8.