Question

Define the term ‘nonsense mutation’ and what causes them.

Answer 1

Answer :- Sometimes mutation produces a base sequence that doesn't code for any amino acid. In such cases , termination of the synthesis of protein occurs at this point. This mutation is called non-sense mutation or chain termination mutation.

Cause of non-sense mutation :-

Basically when a Stop codon or non sense codon introduced in the DNA it causes non sense mutation because stop codon actually terminate the protein synthesis and resulting a non functional protein.

Example :- Cystic Fibrosis is a genetical disease which is caused by a non sense mutation. Because cystic fibrosis introduced with the absence of CFTR i.e cystic fibrosis transmembrane conductance regulator. This is a protein which prevent the cystic fibrosis disease but when this CFTR is not made due to non sense mutation it causes cystic fibrosis disease.