Question

which part of dna forms the \backbone\?
a nitrogen bases
b hydrogen bonds
c sugar - phosphate chain
d amino acids

Explanation:

DNA has a double - helix structure. The backbone of DNA is composed of alternating sugar (deoxyribose) and phosphate groups. Nitrogen bases (adenine, thymine, cytosine, guanine) are attached to the sugar and pair with each other via hydrogen bonds in the interior of the helix. Amino acids are the building blocks of proteins, not part of the DNA backbone.

Answer:

C. Sugar - phosphate chain