Definition of transitions and transversions.
In molecular biology, transversion refers to the substitution of a purine for a pyrimidine or vice versa. It can only be reversed by a spontaneous reversion. Because this type of mutation changes the chemical structure dramatically, the consequences of this change tend to be more drastic than those of transitions. Transversions can be caused by ionizing radiation and alkylating agents.
- ^ Mutations & Mutagenesis