Match List-I with List-II.
| List-I | List-II |
|---|---|
| (A) Primary structure of a nucleic acid | (I) A single stranded helix which sometimes folds back on itself |
| (B) Secondary structure of DNA | (II) Information regarding the sequence of nucleotides in the chain |
| (C) Secondary structure of RNA | (III) Information regarding a sequence of bases on DNA which is unique for a person |
| (D) DNA fingerprinting | (IV) Two chains wound about each other and held together by hydrogen bonds between pairs of bases |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A-II, B-IV, C-I, D-III
A nucleic acid is a chain of nucleotides. Its primary structure is the order of the nucleotides; its secondary structure is the way the chain is wound in space, which is different for DNA and RNA.
(A) Primary structure of a nucleic acid — This matches (II) Information regarding the sequence of nucleotides in the chain. It is about the order of nucleotides in any nucleic acid chain, not about one person.
(B) Secondary structure of DNA — This matches (IV) Two chains wound about each other and held together by hydrogen bonds between pairs of bases. This is the double strand helix given by Watson and Crick.
(C) Secondary structure of RNA — This matches (I) A single stranded helix which sometimes folds back on itself. RNA has one strand, not two.
(D) DNA fingerprinting — This matches (III) Information regarding a sequence of bases on DNA which is unique for a person. The sequence is the same in every cell of that person and cannot be altered by any known treatment.
NCERT (2026-27 edition):
10.5.2 Structure of Nucleic Acids – “Information regarding the sequence of nucleotides in the chain of a nucleic acid is called its primary structure. Nucleic acids have a secondary structure also. 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.”
“In secondary structure of RNA single stranded helics is present which sometimes foldsback on itself.”
DNA Fingerprinting – “…A sequence of bases on DNA is also unique for a person and information regarding this is called DNA fingerprinting. It is same for every cell and cannot be altered by any known treatment.”