Question

Abrupt and distinct changes in the structure of a gene is called as:-

• A. Point mutation
• B. Forward mutation
• C. Backward mutation
• D. Chromosomal aberration

Answer 1

The correct option is A Point mutation

Mutation in single nucleotide base of a DNA segment is called as a point mutation. It can introduce a premature stop codon, or a nonsense codon, by addition or deletion of the base, in the transcribed mRNA (nonsense mutation) or changes a codon specifying a different amino acid by substitution of one base (missense mutation). Chromosomal aberrations are structural and numerical changes in chromosomes, it includes aneuploidy, polyploidy, inversion, translocation, deletion, etc. Any mutation which renders a functional wild gene into non-functional form is called as the forward mutation. The mutation in the mutant form of a gene that restores its wild-type form is a backward mutation. The correct answer is A.