Which mutation category describes a change in a single nucleotide site in the DNA sequence?

Which mutation category describes a change in a single nucleotide site in the DNA sequence?

• A. Point mutations
• B. Frameshift mutations
• C. Inversion mutations
• D. Nonsense mutations

Answer: (A)

A single-nucleotide change in DNA is described by point mutations. This category covers substitutions where one base is replaced by another at a specific site, altering the sequence at that one location. Frameshift mutations come from insertions or deletions that shift the entire reading frame, not just one nucleotide. Inversion mutations involve flipping a DNA segment’s orientation, which is a bigger structural change. Nonsense mutations are a specific outcome within point mutations where a codon is changed to a stop codon, but the general category for a one-nucleotide change is point mutations.

A single-nucleotide change in DNA is described by point mutations. This category covers substitutions where one base is replaced by another at a specific site, altering the sequence at that one location. Frameshift mutations come from insertions or deletions that shift the entire reading frame, not just one nucleotide. Inversion mutations involve flipping a DNA segment’s orientation, which is a bigger structural change. Nonsense mutations are a specific outcome within point mutations where a codon is changed to a stop codon, but the general category for a one-nucleotide change is point mutations.