Question

How is frame-shift mutation different from point mutation?

Answer 1

Frame-shift mutation and point mutation differ mainly in their effect on the genetic code reading frame. Frame-shift mutation occurs due to the deletion or addition (insertion) of one or more nucleotides in a DNA segment. This shifts the reading frame of codons from the mutation site onward, causing drastic changes in the amino acid sequence of proteins, often leading to harmful effects. In contrast, point mutation refers to the change of a single nucleotide at a fixed point on the chromosome, usually by substitution. Point mutations might or might not affect the protein depending on whether the altered codon codes for the same or a different amino acid. Therefore, frame-shift mutations generally have more severe effects compared to point mutations because they alter the entire protein sequence downstream of the mutation site.