Question

a model of dna is shown.
which label identifies a hydrogen bond?
a. structure 1
b. structure 2
c. structure 3
d. structure 4

Explanation:

• Structure 1 is the sugar-phosphate backbone (covalent bonds).
• Structure 2 is a covalent bond in the backbone.
• Structure 3 is the 5' end of a DNA strand.
• Structure 4 is the weak bond connecting complementary base pairs, which are hydrogen bonds that hold the two DNA strands together.

Answer:

D. Structure 4