Question

Which of the following frameshift mutations might be expected to have the least impact on an organism? (1 point)

a deletion of two nucleotides near the beginning of a gene
an insertion of three nucleotides in the middle of a gene
a deletion of four nucleotides near the end of a gene
an insertion of five nucleotides at a gene’s promoter site

Answer 1

I would think it's the insertion of three nucleotides.

codons come in pars of three, so if you add one codon (3 nucleotides) then you just an an extra amino acid. However, if you delete/insert anything that is not 3 nucleotides, your whole sequence will get shifted, so anything upstream from that modification will code for different amino acids (and thus resulting in a very different polypeptide). Also, the deletion of the four nucleotides at the end of the gene can be problematic since it will "ruin" the stop sequence (most likely)

Answer 2

thank you.

Answer 3

yw :)