In nucleic acids, what is the primary role of the nitrogenous bases?

• A. They form the sugar-phosphate backbone of the nucleic acid.
• B. They store genetic information through specific base pairing.
• C. They catalyze the polymerization of nucleotides.
• D. They provide energy for cellular processes.

Answer: (B)

Verified step by step guidance

1. Understand the structure of nucleic acids: Nucleic acids, such as DNA and RNA, are composed of three main components—nitrogenous bases, a sugar molecule (deoxyribose or ribose), and a phosphate group. The nitrogenous bases are adenine (A), thymine (T), cytosine (C), guanine (G), and uracil (U in RNA).
2. Learn the role of nitrogenous bases: Nitrogenous bases are critical for storing genetic information. They pair specifically (A with T, and C with G in DNA; A with U, and C with G in RNA) through hydrogen bonding, forming the rungs of the nucleic acid's double helix structure.
3. Understand base pairing: The specific pairing of nitrogenous bases ensures the accurate replication and transcription of genetic information. This is essential for the inheritance of traits and the synthesis of proteins.
4. Differentiate the roles of other components: The sugar-phosphate backbone provides structural support to the nucleic acid, while the nitrogenous bases are directly involved in encoding genetic information. They do not catalyze reactions or provide energy for cellular processes.
5. Conclude the primary role: The nitrogenous bases store genetic information through their specific base pairing, which is fundamental to the function of nucleic acids in living organisms.