1. nucleotides encode a single amino acid For 4 nucleotides to encode 20 amino acids, you need a coding unit of at least 3 A coding unit of 2 nucleotides can only encode 16 amino acids(4x4 A coding unit of 3 nucleotides can only encode 64 amino acids(4x 4x4) Insertions or deletions of 1. 2 4 5. etc nucleotides cause a severe loss of function resulting from a change in the reading frame But insertions or deletions of 3.6.9. etc have little effect on the phenotype, because the reading frame is not affected for most of the mRNa1. 3nucleotides encode a single amino acid • For 4 nucleotides to encode 20 amino acids, you need a coding unit of at least 3: – A coding unit of 2 nucleotides can only encode 16 amino acids (4x4) – A coding unit of 3 nucleotides can only encode 64 amino acids (4x4x4) • Insertions or deletions of 1, 2, 4, 5, etc nucleotides cause a severe loss of function resulting from a change in the reading frame. • But insertions or deletions of 3, 6, 9, etc have little effect on the phenotype, because the reading frame is not affected for most of the mRNA