Question

which is a point mutation and not a frameshift mutation?
mutagen
insertion
deletion
silent

Explanation:

A point - mutation is a change in a single nucleotide. A silent mutation is a type of point - mutation where the change in the nucleotide sequence does not result in a change in the amino - acid sequence due to the degeneracy of the genetic code. Insertion and deletion can be frameshift mutations if they are not in multiples of three nucleotides. A mutagen is an agent that causes mutations, not a type of mutation itself.

Answer:

D. silent