Question

The couplings between base units of DNA is through

(a) hydrogen bonding

(b) electrostatic bonding

(c) covalent bonding

(d) van der Waals forces.

Answer 1

Correct option(a) hydrogen bonding

Explanation :

Hydrogen bonding

Double helical structure of DNA: Double helix is composed of two right-handed helical polynucleotide chains coiled around the same central axis. The two strands are antiparallel. The bases are stacked inside the helix in planes perpendicular to the helical axis. The two strands are held together by hydrogen bonds. Two hydrogen bonds between A and T(A=T) and three are formed between C and G (C≡G).