How is all of that DNA packaged so tightly into chromosomes and squeezed into a tiny nucleus? Long, slender DNA molecules wind around proteins and fold in complex ways to form chromosomes.

Each of us has enough DNA to reach from here to the sun and back, more than 300 times. How is all of that DNA packaged so tightly into chromosomes and squeezed into a tiny nucleus?

The picture shows a close-up of one carbon atom. A hydrogen atom has one proton as the nucleus and one electron in the region outside the nucleus. The electron and proton are attracted to each other.