Starting with mRNA in the nucleus, which sequence best describes how translation produces a polypeptide?

Starting with mRNA in the nucleus, which sequence best describes how translation produces a polypeptide?

• A. DNA is transcribed into mRNA, which directly becomes a polypeptide in the nucleus.
• B. Ribosomes synthesize mRNA using amino acids as building blocks.
• C. mRNA leaves nucleus, ribosome binds, tRNA brings amino acids, anticodon pairs, peptide bonds form, polypeptide released.
• D. mRNA leaves nucleus, ribosome binds, but no tRNA involved.

Answer: (C)

Translation uses mRNA as the template to build a polypeptide at the ribosome after the mRNA exits the nucleus. The ribosome binds the mRNA and reads its codons. Each codon is matched by a tRNA carrying the corresponding amino acid, with the tRNA’s anticodon pairing to the codon. The ribosome then forms peptide bonds between successive amino acids, creating the growing polypeptide chain. When a stop codon is encountered, the process ends and the completed polypeptide is released. This sequence—mRNA leaving the nucleus, ribosome binding, tRNA delivering amino acids with proper codon-anticodon pairing, peptide bond formation, and release of the polypeptide—best describes how translation produces a protein. The other options are incorrect because translation does not occur in the nucleus, ribosomes do not make mRNA from amino acids, and tRNA is required to bring amino acids.

Translation uses mRNA as the template to build a polypeptide at the ribosome after the mRNA exits the nucleus. The ribosome binds the mRNA and reads its codons. Each codon is matched by a tRNA carrying the corresponding amino acid, with the tRNA’s anticodon pairing to the codon. The ribosome then forms peptide bonds between successive amino acids, creating the growing polypeptide chain. When a stop codon is encountered, the process ends and the completed polypeptide is released. This sequence—mRNA leaving the nucleus, ribosome binding, tRNA delivering amino acids with proper codon-anticodon pairing, peptide bond formation, and release of the polypeptide—best describes how translation produces a protein. The other options are incorrect because translation does not occur in the nucleus, ribosomes do not make mRNA from amino acids, and tRNA is required to bring amino acids.