we know that nitrogenous bases are four ( adnine- thyamine-cytosin-guanine) each three of them translate to the 21th amino acids and the 4 N-bases power 3 (the codon of each amino acid) equal 64 not 21
so my question is what is the role of this extracodon???? 🙄
well if you only had 21 codons (what’s your 21st codon by the way, selenocysteine?) and the rest up until 64 were stop codons, then you would have a lot of nonsense mutations. being degenerate makes a lot of mutations silent.