Question

A normal sequence in the DNA code CCG -TTG-CAT. it turns out after 20 years of smoking, the same individual's code is now CCG-ATC-GCAT... what happened to the original code

Answer 1

Answer: There was a single nucleotide polymorphism (SNP) in the second codon and an insertion between the first and second codon

Explanation:

SNP: CCG-TTG-CAT --> CCG-TCG-CAT pro-leu-his --> pro-ser-his, change in one amino acid

insertion: CCG-TCG-CAT --> CCG-ATC-GCA-T pro-ser-his --> pro-ile-ala, change of reading frame