question_answer 64)

  There is only one possible sequence of amino acids when deduced from agiven nucleotides. But multiple nucleotides sequence can be deduced from a single amino acid sequence. Explain this phenomena.

Answer:

                  Some amino acids are coded by more then one codon (known as degeneracy of codons),hence, on deducing a nucleotide sequence from an amino acid sequence, multiple nucleotide sequence will be obtained, e.g., lie (Isoleucine) has three codons AUU, AUC,AUA. Hence, a dipeptide Met-lle can have the following nucleotide sequence. (i) AUG-AUU                      (ii) AUG.-AUC     (iii) AUG-AUA And if, we deduce amionacid sequence from the above nucleotide sequences, all the threewill code for Met-lle.