Information in DNA and RNA is stored in the sequence of the nitrogenous bases. Information is contained in which component?

• A. Sugars
• B. Nitrogenous bases
• C. Phosphate groups
• D. Amino acids

Answer: (B)

The information carried by DNA and RNA is stored in the sequence of nitrogenous bases along the nucleic acid strand. The order of these bases—adenine, thymine (DNA)/uracil (RNA), cytosine, and guanine—codes genetic information, with specific sequences marking genes and regulatory regions. The sugars and phosphate groups form the backbone that holds the bases in place, giving the molecule its structure, but they do not vary in a way that encodes information. Amino acids are the building blocks of proteins and are specified by the base sequences, not stored as information themselves. So the component that actually carries the informational content is the nitrogenous bases.