Question

Statement A - Polypeptide synthesis stops when a termination codon is read at the A-site.
Statement B - The termination codon attracts AA-tRNA.

• A. Both statement A and B are correct, and B is the correct reason for A.
• B. Both statement A and B are correct, but B is not the correct reason for A.
• C. Only statement A is correct.
• D. Only statement B is correct.

Answer 1

The correct option is C Only statement A is correct.

Termination codons are those codons that do not code for any amino acid. They are also known as stop codons or nonsense codons. There are three such codons - UAA, UAG and UGA.
When any of these codons are read at the A-site, the release factor binds to this site. Thus the process of translation is terminated. There are no tRNAs for stop codons.