Question

the two strands of a dna double helix are held together by ______ that form between pairs of nitrogenous bases. s—s bonds ionic bonds hydrophilic interactions hydrogen bonds covalent bonds

Explanation:

The two strands of a DNA double - helix are held together by hydrogen bonds between complementary nitrogenous bases (adenine - thymine and guanine - cytosine). S - S bonds, ionic bonds, hydrophilic interactions, and covalent bonds do not play this role in holding the two strands of DNA together.

Answer:

D. hydrogen bonds