Types of Gene Mutations
Since we're talking about mutations, it is necessary for us to understand how mutations are classified. Mutations that occur under natural conditions without the action or effect of an external agent are called spontaneous mutations. For example, bacteria, archae, and eukaryotic microbes produce roughly one mutation per 300 chromosome replications. The other type of mutation is an Induced mutation, which, as the name suggests, involves the role of external agent.
Classification of Mutations:
A silent mutation does not alter the message or the protein sequence of the gene/DNA and therefore considered to be a 'silent' mutation, as there is no no final effect.
A substitution mutation involves a change in the DNA sequence, which eventually leads to changes in the amino acid sequence where one amino acid is replaced for another. Hence the name substitution mutation.
As the name suggests, deletion mutation involves deletion of part of a chromosome or a few bases from the DNA sequence. This type of mutation is severe and is also evolutionarily significant as this can be used to trace the phylogeny of organisms.