Biomolecules — Chemistry STD 12 Science — Question

1. 5, 3 locations

Explanation:

In the nucleic acids, the phosphate ions are bonded with sugar at 5, 3 locations.

The sugars and phosphates in nucleic acids are connected to each other in an alternating chain (sugar-phosphate backbone) through phosphate diesters linkages. 

The carbons to which the phosphate groups attach are the 3'-end and the 5'-end carbons of the sugar.

This gives nucleic acids directionality, and the ends of nucleic acid molecules are referred to as 5'-end and 3'-end.