Chromosomes and Chromatin!
Inside of the nuclear envelope are fine strands of chromatin, a combination of DNA and protein. When the cell is about to divide into two, the chromatin strands coil up and become densely packed forming chromosomes. Chromosomes contain DNA-bonded proteins, which serve to package the DNA and control its function. Chromosomes exist in all cells for without the cells DNA would not function correctly.
http://www.futurity.org/wp-content/uploads/2010/09/cells_1.jpg
http://lifesciencedaily.com/wp-content/uploads/2011/05/chromosomes.jpg
http://www.cgl.ucsf.edu/chimera/data/multiscale02/nucleosome-edge.png
http://www.futurity.org/wp-content/uploads/2010/09/cells_1.jpg
http://lifesciencedaily.com/wp-content/uploads/2011/05/chromosomes.jpg
http://www.cgl.ucsf.edu/chimera/data/multiscale02/nucleosome-edge.png