Standard base pairing in DNA occurs due to which type of bonding?

Correct option is C

The correct answer is (c) Hydrogen bonding

Explanation:

• Standard base pairing in DNA involves specific pairing between nitrogenous bases: Adenine with Thymine and Guanine with Cytosine.
• These pairs are held together by hydrogen bonds — a type of weak chemical interaction.
• Adenine (A) forms two hydrogen bonds with Thymine (T).
• Guanine (G) forms three hydrogen bonds with Cytosine (C).
• These hydrogen bonds provide stability to the DNA double helix while allowing the strands to separate during replication and transcription.

Information Booster:

• DNA has a double helix structure as proposed by Watson and Crick in 1953.
• The sugar-phosphate backbone is held together by covalent bonds, but the base pairs are connected via hydrogen bonds.

Additional Knowledge:

Van Der Waals interactions (Option a)

• These are weak attractions between molecules or parts of molecules.
• They help stabilize the stacked bases in DNA but are not responsible for base pairing.

Ionic bonding (Option b)

• Involves electrostatic attraction between oppositely charged ions.
• Not involved in the bonding of DNA base pairs.

Covalent bonding (Option d)

• Strong bonds formed by sharing electrons.
• Present in the sugar-phosphate backbone of DNA, not between base pairs.