Write a note on point mutation.

Explanation

Point mutation:
It refers to alterations of single base pairs of DNA or of a small number of adjacent base pairs.
Types of point mutations
(i) Point mutation in DNA are of two main types. (i) Base pair substitutions (2) Base pair insertions or deletions.
(ii) Base substitutions are mutations in which there is a change in the DNA such that one base pair is replaced by another. It can be divided into two subtypes: transitions and transversions.
(iii) Addition or deletion mutations are actually additions or deletions of nucleotide pairs and also called base pair addition or deletions. Collectively, they are termed indel mutations (for insertion-deletion). Substitution mutations or indel mutations affect translation. Based on these different types of mutations are given below.
Silent mutation / Synonymous mutation: The mutation that changes one codon for an amino acid into another codon for that same amino acid.
Missense or non-synonymous mutation: The mutation where the codon for one amino acid is changed into a codon for another amino acid.
Non-sense mutation: The mutations where codon for one amino acid is changed into a termination or stop codon.
Frameshift mutation: Mutations that result in the addition or deletion of a single base pair of DNA that changes the reading frame for the translation process as a result of which there is complete loss of normal proteih structure and function.