Explain how DNA which is 6 feet long can be stored in the nucleus of a tiny human cell

DNA is twisted in a double helix, then wrapped around proteins and condensed into chromosomes. This "packaging" is what allows a six-foot-long DNA molecule to fit into the nucleus of a tiny cell.

The DNA is ultimately wound up really tightly around a group of proteins known as histones. This then forms loops of DNA which are called nucleosomes. The nucleosomes then coil and stack on top of each other to form fibers called chromatin - these then form larger loops and coils to form chromosomes.