Question

what is the backbone of dna composed of? peptides sugar - phosphate lipid - nitrate

Explanation:

The DNA backbone is known to be composed of a sugar - phosphate group. Peptides are related to proteins, and lipid - nitrate is not a component of the DNA backbone. So the correct option is the one with "sugar - phosphate".

Answer:

B. sugar - phosphate (assuming the options are labeled as A. peptides, B. sugar - phosphate, C. lipid - nitrate)