Translation: anticodon-codon pairing in protein synthesis

Steps:

• Identify X as the tRNA component that base-pairs with mRNA during translation.
• Identify Y as the mRNA triplet sequence specifying an amino acid.
• Identify Z as the adaptor molecule carrying the amino acid to the ribosome.
• Match labels to standard roles: X=anticodon, Y=codon, Z=tRNA.

Why B is correct:

• In translation, the anticodon (X) on tRNA (Z) binds the codon (Y) on mRNA via complementary base pairing.

Why the others are wrong:

• A: Includes mRNA instead of tRNA, but Z is the tRNA molecule, not mRNA.
• C: Reverses X and Y; anticodon is on tRNA, codon on mRNA.
• D: Reverses X and Y; order mismatches standard labeling of anticodon first, then codon.

Final answer: B