RNA is a polymer of ribonucleotides. This makes option (C) the correct answer for the CSIR NET Life Sciences question.

Option Analysis

Glycosides (A): Glycosides are compounds formed by a sugar (glycone) linked to a non-sugar (aglycone), common in plants but unrelated to nucleic acid polymerization. They lack phosphate and nitrogenous bases needed for RNA structure.

Ribonucleosides (B): Ribonucleosides consist of ribose sugar bonded to a nitrogenous base (e.g., adenosine), but lack the phosphate group essential for forming RNA’s phosphodiester backbone linkages.

Ribonucleotides (C): Correct. Ribonucleotides (e.g., ATP, GTP) include ribose, a base (A, U, G, C), and phosphate groups. RNA polymerase links these via phosphodiester bonds, creating the polynucleotide chain.

Riboses (D): Ribose is just the pentose sugar in RNA, without bases or phosphates. It cannot form the polymeric chain alone.

RNA is a polymer of ribonucleotides, the fundamental building blocks essential for genetic information transfer in cells. This key concept appears frequently in CSIR NET Life Sciences exams, testing understanding of nucleic acid structure.

RNA Structure Basics

RNA forms a single-stranded polynucleotide chain where ribonucleotides link via 3′-5′ phosphodiester bonds. Each ribonucleotide comprises ribose sugar, phosphate, and bases adenine (A), uracil (U), guanine (G), or cytosine (C). Unlike DNA, RNA uses uracil instead of thymine and ribose over deoxyribose.

Why Ribonucleotides?

RNA polymerase catalyzes polymerization using ribonucleoside triphosphates (NTPs) like ATP. The reaction releases pyrophosphate, extending the chain. This process ensures RNA’s role in mRNA, tRNA, and rRNA for protein synthesis.

• Key Differences from DNA: DNA uses deoxyribonucleotides (deoxyribose lacks one oxygen).

• Functions: Messenger RNA carries genetic code; transfer RNA delivers amino acids.

Exam Tips for CSIR NET

Master distinctions: nucleosides (sugar + base) vs. nucleotides (sugar + base + phosphate). Practice similar MCQs on biomolecules for qualifying rounds.