If an mRNA segment contains five distinct codons, how many different tRNA molecules would be required to translate it?

• A. 4
• B. 6
• C. 5
• D. 7

Answer: (C)

Translation uses tRNA molecules whose anticodons pair with mRNA codons to bring the correct amino acids to the ribosome. Each distinct codon is read by a tRNA that has a complementary anticodon, delivering its specific amino acid. If the mRNA segment contains five distinct codons, you would typically need five tRNA molecules to recognize and translate each one. While wobble at the third base can allow a single tRNA to pair with multiple codons in some cases (especially when those codons code the same amino acid), the straightforward expectation for five distinct codons is that five different tRNA species are required to ensure each codon is correctly translated.