Identify the linkage in backbone of single strand of DNA ?

Step-by-step solution

The backbone of a single strand of DNA is formed by alternating sugar and phosphate molecules. The nitrogenous bases are attached to the sugar molecules and project outwards from the backbone, meaning they are not part of the continuous backbone chain. Thus, the continuous chain forming the backbone consists of phosphate-sugar-phosphate linkages. Answer: Phosphate -sugar-phosphate