Amutation occurs at the midpoint of a gene, altering all amino acids encoded after the point of mutation. which mutation could have produced this change? deletion of two nucleotides insertion of twelve nucleotides insertion of six nucleotides deletion of three nucleotides

Deletion of two nucleotides.

Explanation:

Every amino acid coded by 3 nucleotides.

12:3=4 (amino acids)

6:3=2 (2 amino acids)

3:3=1 (1 amino acid)

After all of these mutations sequence amino acids change, but after continues stay the same.

Only deletion of 2 nucleotides will completely altered all amino acids encoded without mutation.