試題詳解

16. About mutation, which of the following stateme ent is TRUE?
(A) Silent mutations usually do not have obser rvable effects on phenotypes becaus se they are in-frame mutations
(B) Missense mutations change a codon into a stop codon leading to a trunc cated protein
(C) Nonsense mutation is a point mutation in which a single nucleotide change resulted in a a change in an amino acid
(D) Insertions and deletions are additions or losses of nucleotide pairs in a gene that alter the reading frame producing out-of-frame mutations