Which one of the followings is not a terminator codon?

The correct answer is Option (3) → UUC

The genetic code has 64 codons. Of these, 61 codons code for amino acids. The other 3 codons do not code for any amino acid, so they work as stop (terminator) codons. They are UAA, UAG and UGA. At a stop codon a release factor binds, and translation ends.

(1) UAA — A terminator codon.

(2) UAG — A terminator codon.

(3) UUC — Not a terminator codon. It codes for the amino acid phenylalanine, so translation goes on.

(4) UGA — A terminator codon.

NCERT Extract:
Genetic Code – “… (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.”
Genetic Code – “… (vi) UAA, UAG, UGA are stop terminator codons.”