What made up the two chain of DNA?

Answer 1

DNA is composed of two chains so as to avoid the crumbling of the long strand that make up the whole genome.

DNA is actually composed of the phosphodiester backbone consisting of the deoxyribose sugar molecules polymerized with alternately present phosphate molecules. Another very important part of the DNA are the purines and the pyrimidines, the sequence of which give the species their specific characters and also distinguish between you and me.

Purines and pyrimidines are hydrophobic in nature, i.e., they fear water and tend to run away from it. Thus, they aggregate among each other so as to keep them all associated close together and away from water. With a second strand present, they do not need to crumble and thus a stable helix exists.

This stable helix is extremely important so as to carry out vital processes like transcription and replication smooth.

Answer 2

Two chains of subunits called nucleotides. Each nucleotide is a sugar, a phosphate group and a nitrogenous base.