Which codon has dual functions?

AUG

The correct answer is Option (4) → AUG

AUG has dual functions. It codes for Methionine (met) , and it also act as initiator codon.

AUG is known as the start codon and also codes for the amino acid Methionine in the genetic code. It serves as the initiation signal for protein synthesis, marking the starting point for translation and the incorporation of Methionine into the growing polypeptide chain during protein synthesis.

UAA, UAG, UGA are stop terminator codons.