Based on the gene and protein sequences that follow, what type of mutation has occurred and what is the effect on the polypeptide?​

a. Normal gene: ATGGCCGGCCCGAAAGAGACC
b. Mutated gene: ATGGCCGGCACCGAAAGAGACC ​
c. Normal protein: Met-Ala-Gly-Pro-Lys-Glu-Thr
d. Mutated protein: Met-Ala-Gly-Thr-Glu-Arg-Asp