Practice question

Transversion mutation substitutes purine for pyrimidine or vice versa, for example A→C, A→T, G→C, G→T and reciprocal changes, involving interconversion of double-ring and single-ring structures. This creates larger geometric distortion than transition, often triggering repair recognition yet when fixed causes more dramatic chemical change. Transversions can result from oxidative damage generating 8-oxo-guanine pairing with adenine or from alkylation products. Their occurrence produces stronger effects on protein coding due to greater likelihood of non-conservative amino acid replacement. This principle illustrates essential molecular mechanisms governing replication fidelity and mutation fixation relevant for exam interpretation.