How do our bodies contain the instructions for those 20,000 proteins? Stretched end to end, the DNA in any one of our cells is 6 feet long and if you could uncoil all of the DNA in your body it would stretch billions of miles; that’s a lot of DNA! Rather than being packed loosely inside the nucleus, it is wound around protein molecules called histones and packaged into condensed structures called chromosomes. Humans have 23 pairs of chromosomes–one set from each genetic parent. The information contained within those 23 pairs of chromosomes is your entire genome. It’s the encyclopedia of you.