Which mutation arises from the addition of one or more base pairs into the DNA sequence?

Which mutation arises from the addition of one or more base pairs into the DNA sequence?

• A. Deletion mutation
• B. Point mutation
• C. Insertion mutation
• D. Trinucleotide repeat disease

Answer: (C)

Adding one or more base pairs into the DNA sequence is an insertion mutation. It introduces extra nucleotides into the genome, which can disrupt the gene’s encoded protein. In a coding region, an insertion often shifts the reading frame, changing every downstream codon (a frameshift) and usually producing a nonfunctional protein. If the number of added bases is a multiple of three, the reading frame remains intact but the protein gains extra amino acids, which can still impair function. This description matches the concept of insertion precisely. Deletion mutations involve removing bases, point mutations are single base substitutions, and trinucleotide repeat diseases result from expansions of specific three-nucleotide motifs, not simple insertions of arbitrary base pairs.

Adding one or more base pairs into the DNA sequence is an insertion mutation. It introduces extra nucleotides into the genome, which can disrupt the gene’s encoded protein. In a coding region, an insertion often shifts the reading frame, changing every downstream codon (a frameshift) and usually producing a nonfunctional protein. If the number of added bases is a multiple of three, the reading frame remains intact but the protein gains extra amino acids, which can still impair function. This description matches the concept of insertion precisely. Deletion mutations involve removing bases, point mutations are single base substitutions, and trinucleotide repeat diseases result from expansions of specific three-nucleotide motifs, not simple insertions of arbitrary base pairs.