Pretty check answers
3. what structural problem prevents adenine from pairing with guanine?
the bases are both short.
they lack phosphate groups.
they lack the deoxyribose group.
the bases are both long.

"The bases are both long" is the one structural problem among the following choices given in the question that prevents adenine from pairing with guanine. The correct option among all the options that are given in the question is the last option or the fourth option. I hope that this is the answer that has come to your help.