-DNA is a double-stranded helix-Two polynucleotide strands (that run antiparallel to each other), held together by hydrogen bonding between the complementary base pairs-Each nucleotide consists of deoxyribose sugar, a phosphate group and a base (adenine [A), thymine [T], cytosine [C] and guanine [G] in the case of DNA).-The two strands are equidistant and the double helix is stable due to complementary base pairing, which means that A+T always pair together, and C+G always pair together