4 Question Nitrogen bases . are attached to the sugar- phosphate backbone in nucleic acid molecules through: __ 1. Phosphodiester bonds 2. O-glycosidic bonds 3. Electrostatic interactions 4. Hydrogen bonds 5. N-glycosidic bonds 6. Disulfide bonds

The correct answer is 5. N-glycosidic bonds.<br /><br />In nucleic acid molecules, nitrogen bases are attached to the sugar-phosphate backbone through N-glycosidic bonds. These bonds form between the nitrogen atom of the base and the carbon atom of the sugar in the backbone. This attachment links the nitrogenous base to the deoxyribose or ribose sugar, which is part of the sugar-phosphate backbone of the nucleic acid molecule.