Which type of mutation affects a single nucleotide through substitution, insertion, or deletion?

A point mutation is a change that occurs at a single nucleotide in the DNA sequence. This type of mutation can happen through three primary mechanisms: substitution, insertion, or deletion.

When a single nucleotide is substituted for another, it results in a change in the codon, potentially leading to a different amino acid (as in a missense mutation) or a stop codon (as in a nonsense mutation). Insertion or deletion of a single nucleotide can shift the reading frame of the genetic code, which can drastically alter the entire protein produced, but the initial change is still classified as a point mutation since it starts with just one nucleotide being altered.

This distinction is crucial because it influences how mutations affect protein synthesis and the resultant traits in an organism. Understanding point mutations is foundational when studying genetic disorders or exploring the principles of molecular biology and genetics.