Figure 1 - DNA molecules can adopt a tightly wound shape, shown here, when packaged inside the nucleus of a cell11.
From the following article
Polymer Physics: DNA off the Hooke
Rudolf Podgornik
Nature Nanotechnology 1, 100 - 101 (2006)
doi:10.1038/nnano.2006.114

D. S. GOODSELL; PDB
