Which codon has a dual function in the genetic code?

Step-by-step solution

The salient features of the genetic code are as follows: (i) The codon is triplet. 61 codons code for amino acids and 3 codons do not code for any amino acids, hence they function as stop codons. (ii) Some amino acids are coded by more than one codon, hence the code is degenerate. (iii) The codon is read in mRNA in a contiguous fashion. There are no punctuations. (iv) The code is nearly universal: for example, from bacteria to human UUU would code for Phenylalanine (phe). Some exceptions to this rule have been foun