Question

A deletion mutation will also be a frameshift mutation if

A) the deletion is any length except a multiple of 3 bases

B) the deletion is within the gene coding sequence

C) both A and B are required

D) any deletion is by definition a frameshift

Answer 1

Sol.

The insertion or deletion of any number of bases which are not divisible by three changes the reading frame from the point of insertion or deletion. Such mutations are referred to as frame shift insertion or deletion mutation.

Insertion or deletion of three or its multiple bases insert or delete one or multiple codon hence one or multiple amino acids and reading frame remains unaltered from that point onwards.

So, a deletion mutation will also be a frame shift mutation if

1. The deletion is any length except a multiple of three bases and
2. The deletion is within the gene coding sequence.

Hence, option (c) i.e. "both (a) and (b) are required" is the correct answer for this question.