Question

multiple select question select all that apply which of the following statements are true regarding the dna structure? hydrogen bonds can form either between two purines or else between two pyrimidines. the nitrogenous bases face the inside and hold the two backbones together with hydrogen bonds. the basic three - dimensional structure of dna is the double helix. each sidepiece is a sugar - phosphate backbone composed of phosphate groups alternating with the sugar deoxyribose.

Explanation:

Answer:

The nitrogenous bases face the inside and hold the two backbones together with hydrogen bonds.
The basic three - dimensional structure of DNA is the double helix.
Each sidepiece is a sugar - phosphate backbone composed of phosphate groups alternating with the sugar deoxyribose.