Question

The backbone of a polynucleotide chain is formed by which components?

Options

• Sugar and phosphate groups

• Nitrogenous bases and phosphate groups

• Nitrogenous bases and sugar

• Only phosphate groups

Answer 1

The backbone of a polynucleotide chain is formed by alternating sugar and phosphate groups connected by phosphodiester bonds. The nitrogenous bases are attached to the sugar molecules via N-glycosidic bonds and project from the backbone.