James Watson and Francis Crick gave a double strand helix structure for DNA. Two Nucleic acid chains are wound about each other and held together by hydrogen bonds between pairs of bases. The two strands are complementary to each other because the hydrogen bonds are formed between specific pairs of bases. Adenine forms hydrogen bonds with thymine whereas cytosine forms hydrogen bonds with guanine.
The sugar component in RNA molecule is ___________.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → D - Ribose
A nucleotide has three parts: a nitrogenous base, a pentose sugar and a phosphate group. The sugar in RNA is D-ribose (present as β-D-ribose in the ring form). In DNA the sugar is β-D-2-deoxyribose, which has no –OH group at C-2. Glucose is a hexose and is not a part of nucleic acids.
NCERT (2026-27 edition):
Chemical Composition of Nucleic Acids
Note: The same/similar question has been asked in different years by NTA as per the details given below:
| 2026 | 2025 | 2024 | 2023 | 2022 |
|---|---|---|---|---|
| 19-05 S1 | – | – | 02-07 S3 | – |