Transition mutations: purine for putine or pyrimidine for pyrimidine substitutions relatively common Transversion mutations: a purine is substituted for a pyrimidine, or a pyrimidine for a purine rarer
• Transition mutations: purine for putine or pyrimidine for pyrimidine substitutions. relatively common • Transversion mutations: a purine is substituted for a pyrimidine, or a pyrimidine for a purine. rarer
of adenine (A Rare and temporary enol ACGTC Wild type tautomeric form of guanine TGCAG A CGTC TGTAG DNA CAT C Mutant repli dication TGTAG ACGTC A C DNA TGCAG T G replication ACGT C Parental DNA Wild type GCAG A CGTC TGCAG r以 Wild type First-generation GCAG progeny Second-generation progeny