A-T base pairs in a DNA double helix
A) are not accessible to DNA binding proteins.
B) are chemically distinct from G-C base pairs.
C) form three hydrogen bonds with each other.
D) are of a different length than G-C base pairs.
E) are more heat stable than G-C base pairs.

Question

Quizplus · Accepted Answer

A-T base pairs have two hydrogen bonds between them, while G-C base pairs have three hydrogen bonds. This means that A-T and G-C base pairs are chemically distinct from each other. The other statements are not true, as A-T base pairs are accessible to DNA binding proteins, are the same length as G-C base pairs, and are actually less heat stable than G-C base pairs.

A-T Base Pairs in a DNA Double Helix