Which among the following codons codes for methionine and also acts as the initiator codon?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → AUG
The genetic code is read in triplets called codons. Of the 64 codons, 61 code for amino acids and three, UAA, UAG and UGA, are stop codons that end translation. One codon, AUG, has two jobs: it codes for the amino acid methionine, and it is the initiator (start) codon where translation begins.
NCERT Extract:
Genetic Code – “… The salient features of 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. … (v) AUG has dual functions. It codes for Methionine (met), and it also act as initiator codon. (vi) UAA, UAG, UGA are stop terminator codons.”