What is the central dogma of molecular biology?

• A. Information flows from DNA to RNA to protein.
• B. Information flows from protein to RNA to DNA.
• C. RNA to DNA to protein.
• D. DNA to protein to RNA.

Answer: (A)

The central idea is that genetic information moves in one direction: DNA is transcribed into RNA, and the RNA is translated into protein. DNA stores the instructions in its sequence, transcription copies that message into messenger RNA, and translation uses that RNA to assemble amino acids into a protein at the ribosome. This flow—DNA to RNA to protein—explains why changes in DNA can influence which proteins are made, affecting cell function and traits. There are notable exceptions, like reverse transcription in retroviruses where RNA is copied into DNA, but these are special cases and do not change the standard path. So the statement that information flows from DNA to RNA to protein is the correct description.