What are the differences between transition and transversion mutation?

Basis of differentiation

Transition mutation 

Transversion mutation 

Definition

Transition mutation is a type of point mutation in which one base (either purine or pyrimidine) is replaced by another base of the same class (purine or pyrimidine). 

Transversion mutation is a type of point mutation in which a purine base is replaced by a pyrimidine base and pyrimidine base is replaced by a purine base.

Ring Structure Change

The ring structure of the nitrogenous base does not undergo any change in a transition mutation

The ring structure of the nitrogenous base changes in a transversion mutation

Significance

The base change occurs within the same class.

The base changes from one class to another. 

Types

There are 8 possible types of transitions. 

There are 4 possible types of transversions.

Possibility per Base

Each base can only undergo a single type of transition.

A base can undergo two types of transversions. 

Occurrence

Transitions occur due to oxidative deamination and tautomerization.

Transversions occur spontaneously or they may be caused due to ionizing radiation and alkylating agents. 

Occurrence in the Genome

Transition mutations are more common in the genome.

Transversion mutations are comparatively less common in the genome. 

Effect

Transitions occur as silent mutations and are less likely to result in amino acid substitutions. 

Transversions have a more pronounced effect. This is because a transversion of the 3rd nucleotide of a codon typically causes the codon to degenerate.