Question

multiple - choice question
what is a frameshift mutation?
a substitution mutation shifts the reading frame of the protein coding region to be shifted so that the protein that is made is totally incorrect.
a deletion or insertion of a base causes the reading frame of the protein coding region to be shifted so that the protein that is made is totally incorrect.
rewatch submit

Explanation:

A frameshift mutation occurs when there is an insertion or deletion of nucleotides (not in multiples of three) in the DNA sequence. This disrupts the reading frame (groups of three nucleotides - codons) for protein synthesis. A substitution mutation (where one base is replaced by another) does not cause a frameshift unless it leads to an insertion or deletion - which it typically does not. The key for a frameshift is a change in the number of bases (insertion or deletion) that is not a multiple of three, altering the reading frame.

Answer:

B. A deletion or insertion of a base causes the reading frame of the protein coding region to be shifted so that the protein that is made is totally incorrect.