Central dogma refresher: The final step of gene expression that converts mRNA information into a polypeptide is called what?

Introduction / Context:
Gene expression proceeds from DNA to RNA to protein. Each step has a specific name and enzymology. Recognizing which term corresponds to which step is fundamental in biology, molecular genetics, and biotechnology exams.

Given Data / Assumptions:

• The question refers to the step that produces a polypeptide.
• Template involved is mRNA interacting with ribosomes.
• We are not discussing DNA synthesis or RNA synthesis.

Concept / Approach:

Replication copies DNA to DNA. Transcription copies DNA to RNA. Translation reads mRNA codons at ribosomes to assemble amino acids into a polypeptide. Therefore, the “final step of gene expression” producing protein is translation.

Step-by-Step Solution:

Verification / Alternative check:

Experimental markers such as radiolabeled amino acids incorporate into newly formed proteins only when translation occurs, confirming that translation is the protein-forming step.

Why Other Options Are Wrong:

• Replication produces DNA, not protein.
• Transcription produces RNA, not protein.
• “None of these” is incorrect because translation is correct.

Common Pitfalls:

• Confusing transcription and translation due to similar wording.
• Overlooking that some RNAs (rRNA, tRNA) are functional without translation; however, the question specifically asks about protein synthesis.

Final Answer:

Translation