What is the difference between nucleosides and nucleotides formed upon hydrolysis of DNA?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Presence of phosphoric acid in nucleotides.
The two units are built as follows:
base + sugar → nucleoside
nucleoside + phosphoric acid → nucleotide
So the difference between nucleosides and nucleotides is the presence of phosphoric acid in nucleotides.
Why the other options are incorrect
Option (2) Presence of phosphoric acid in nucleosides — Incorrect. It is the reverse; a nucleoside has no phosphate group.
Option (3) Presence of different sugars — Incorrect. Both come from DNA and contain the same sugar, β-D-2-deoxyribose.
Option (4) Presence of different nitrogenous bases — Incorrect. Both contain the same set of DNA bases (A, G, C, T); the base is not what separates the two terms.
NCERT (2026-27 edition):
Structure of Nucleic Acids
