Which of the Following DNA Mutations is the Most Likely

Question

Which of the following DNA mutations is the most likely to be damaging to the protein it specifies?
A) a base-pair deletion
B) a codon substitution
C) a substitution in the last base of a codon
D) a codon deletion
E) a point mutation

Accepted Answer

A base-pair deletion causes a frameshift mutation, in which the reading frame is shifted by one or more nucleotides, resulting in a completely different amino acid sequence downstream of the mutation. This can have significant impact on the structure and function of the protein. The other mutations listed may still cause changes in the amino acid sequence, but they are less likely to be as damaging as a frameshift mutation.