What is translation?

• A. The process of copying an RNA sequence into a DNA molecule.
• B. The process of assembling amino acids into a polypeptide.
• C. The process of replicating DNA.
• D. The process of synthesizing a polypeptide from mRNA at the ribosome.

Answer: (D)

Translation is the process by which the information in mRNA is used to synthesize a polypeptide at the ribosome. The ribosome reads codons on the mRNA, and tRNA molecules bring the corresponding amino acids, which are linked together to form the growing protein chain. This description—synthesizing a polypeptide from mRNA at the ribosome—captures both the template (mRNA) and the site of synthesis (the ribosome), plus the outcome (a polypeptide).

The other descriptions describe different cellular processes: copying RNA into DNA points to reverse transcription, DNA replication is about copying DNA itself, and simply “assembling amino acids into a polypeptide” lacks the explicit role of the mRNA template and the ribosome that define translation.