The correct statements are: A helical turn consists of about 10 base pairs. The sugar-phosphate backbone is exposed to the solvent, whereas the nitrogenous bases are in the interior of the double helix. The phosphodiester bonds between nucleotide residues run in opposite directions in the two strands. Solution The correct statements are: A helical turn consists of about 10 base pairs. The sugar-phosphate backbone is exposed to the solvent, whereas the nitrogenous bases are in the interior of the double helix. The phosphodiester bonds between nucleotide residues run in opposite directions in the two strands..