Which sequence correctly describes the flow of genetic information in cells?

Which sequence correctly describes the flow of genetic information in cells?

• A. DNA -> RNA -> Protein
• B. RNA -> DNA -> Protein
• C. DNA -> Protein -> RNA
• D. Protein -> RNA -> DNA

Answer: (A)

The flow of genetic information in cells follows DNA to RNA to Protein. DNA holds the instructions; during transcription, RNA polymerase reads DNA and synthesizes Messenger RNA that carries that message. Then during translation, the ribosome reads the mRNA sequence and, with transfer RNAs bringing amino acids, builds a polypeptide that folds into a protein. This direction—DNA to RNA to Protein—explains why it's the correct sequence. Moving information from RNA back to DNA, or from Protein back to nucleic acids, is not how cellular information typically propagates (with rare exceptions like reverse transcription in certain viruses, which isn’t the standard cell process).

The flow of genetic information in cells follows DNA to RNA to Protein. DNA holds the instructions; during transcription, RNA polymerase reads DNA and synthesizes Messenger RNA that carries that message. Then during translation, the ribosome reads the mRNA sequence and, with transfer RNAs bringing amino acids, builds a polypeptide that folds into a protein. This direction—DNA to RNA to Protein—explains why it's the correct sequence. Moving information from RNA back to DNA, or from Protein back to nucleic acids, is not how cellular information typically propagates (with rare exceptions like reverse transcription in certain viruses, which isn’t the standard cell process).