Why can a guanine not be paired with adenine?
A) Guanine is only found in RNA and adenine is found only in DNA.
B) Guanine can form three hydrogen bonds and adenine can form two.
C) Guanine can form only two hydrogen bonds and adenine can form three.
D) Guanine can only pair with thymine.

Question

Quizplus · Accepted Answer

Guanine forms three hydrogen bonds with cytosine, while adenine forms two hydrogen bonds with thymine. This difference in hydrogen bonding prevents guanine from pairing with adenine.

Why Can a Guanine Not Be Paired with Adenine