What compounds are the building blocks of DNA macromolecules?

Nitrogenous bases, phosphate and pentose sugar.

Nitrogenous bases, phosphate and pentose sugar are building blocks of DNA. The nitrogenous bases are purines and pyramidines. The purines are adenine guanine, while the pyramidines are cytosine and thymine. The pentose sugar, phosphate and one nitrogenous base form a long chain called polynucleotide chain. The two chains are joined by weak hydrogen bonds. These DNA strands are of 20 A of diameter. The nucleotides and nuclesides are inter-woven to each other. Thank You.