Question

which answer below accurately describes the structure of dna? (1 point)
nitrogen bases on the outside with sugar - phosphate in the middle of a double helix
sugar - nitrogen base backbone with phosphates in the middle forming a double helix
sugar - phosphate backbone with nitrogen bases in the middle forming a double helix
sugar - phosphate backbone with nitrogen bases coming off a single helix

Explanation:

DNA has a double - helix structure. The sugar - phosphate groups form the backbone (on the outside), and the nitrogen bases (adenine, thymine, cytosine, guanine) are in the middle, paired via hydrogen bonds.

Answer:

Sugar - phosphate backbone with nitrogen bases in the middle forming a double helix.