Question

which type of mutation always produces a stop codon?
missense
nonsense
silent
point

Explanation:

A nonsense mutation changes a codon that specifies an amino - acid into a stop codon, prematurely terminating protein synthesis. Missense mutations change one amino - acid, silent mutations do not change the amino - acid sequence, and point mutations can be missense, nonsense or silent.

Answer:

B. nonsense