Q12 of 71 Page 41

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

Some amino acids are coded by more than one codon. This phenomenon is called as degeneracy of codon. Hence, from such amino acids multiple nucleotide sequence would be obtained. Forexample, Isoleucine has three codons AUU, AUG and AUA.The following nucleotide sequences are obtained:

a) AUG-AUU


b) AUG-AUG


c) AUG-AUA


All the three sequences code for Met-Ile.


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