How many of the following are obtained on complete hydrolysis of RNA?
Adenine, Thymine, Uracil, Guanine, Cytosine, β-D-Ribose, β-D-2-Deoxyribose, Phosphoric acid
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 6
Complete hydrolysis breaks a nucleic acid into three kinds of units: a pentose sugar, phosphoric acid and nitrogen containing bases. RNA and DNA have three bases in common; they differ in the fourth base and in the sugar.
Obtained from RNA:
Adenine
Uracil (the fourth base of RNA)
Guanine
Cytosine
β-D-Ribose (the sugar of RNA)
Phosphoric acid
Not obtained from RNA:
Thymine — a base of DNA; RNA has uracil in its place.
β-D-2-Deoxyribose — the sugar of DNA, not of RNA.
Obtained from RNA: adenine, uracil, guanine, cytosine, β-D-ribose and phosphoric acid = 6.
NCERT (2026-27 edition):
10.5.1 Chemical Composition of Nucleic Acids – “Complete hydrolysis of DNA (or RNA) yields a pentose sugar, phosphoric acid and nitrogen containing heterocyclic compounds (called bases). In DNA molecules, the sugar moiety is β-D-2-deoxyribose whereas in RNA molecule, it is β-D-ribose.”
“DNA contains four bases viz. adenine (A), guanine (G), cytosine (C) and thymine (T). RNA also contains four bases, the first three bases are same as in DNA but the fourth one is uracil (U).”