Question

which of the following frame shift mutations might be expected to have the least impact on an organism
A)a deletion of 2 nucleotides near the beginning of the gene
B)an insertion of 3 nucleotides in the middle of the gene
C)a deletion of four nucleotides near the end of the gene
D)an insertion of 5 nucleotides at a genes promoter site

Answer 1

I‘d like to say, B. 3 nucleotides make up 1 codon, so it's ok, comparatively, to change a whole codon (or 3 integer multiple).

Answer 2

Technically, "B" cannot be a correct answer because it does not cause a frame shift. The question asks "Which of the following frame shifts...."