Describe how the two nucleotide chains in dna are bonded together.

DNA stands for deoxyribonucleic acid and is the carrier molecule for hereditary genetic information.
The DNA molecule is double-stranded, consisting of two complementary polynucleic chains which are antiparallel-facing and which are wound in a double helix (helical form). These two chains are bound by hydrogen bonds between each pair of nucleotides (between guanine and cytosine there are three hydrogen bonds and between adenine and thymine there are two hydrogen bonds). and since the DNA is condensed in the form of chromatin, it also helps to keep this double-stranded structure.