Which is a point mutation and not a frameshift mutation?

A. mutagen

B. insertion

C. deletion

D. silent

Answer

The correct answer to the question is D. silent, as silent mutations are point mutations that do not affect the amino acid sequence produced. In contrast, insertions and deletions are frame-shift mutations that change the reading frame of the genetic code. Point mutations can include silent mutations, missense mutations, and nonsense mutations, all affecting single nucleotide pairs.

Explanation

In the context of mutations, a point mutation is defined as a change in a single nucleotide base pair in the DNA sequence. These mutations can be further categorized into different types based on their effects:

In contrast, frame-shift mutations occur when nucleotides are inserted or deleted from the DNA sequence, altering the reading frame of the genetic code. This can drastically change the protein produced, affecting every amino acid downstream of the mutation.

Among the answer choices provided:

Therefore, the correct answer to the question, which asks for a point mutation and not a frameshift mutation, is D. silent.