The nitrogenous bases (and the two strands of the DNA double helix) are held together by
A) weak van der Waals forces.
B) covalent bonds.
C) hydrogen bonds.
D) Both a and b
E) Both a and c

Question

Quizplus · Accepted Answer

The nitrogenous bases in the DNA double helix are held together by hydrogen bonds. While the phosphodiester backbone is held together by covalent bonds, the hydrogen bonds between complementary nitrogenous bases hold the two strands of DNA together. Though van der Waals forces do play a role in the stability of the double helix, they are not responsible for holding the nitrogenous bases together.

The Nitrogenous Bases (And the Two Strands of the DNA