So chromatin has within it DNA, it has protein, and it has a little bit of RNA in it. And we’re going to focus mostly on the DNA in the chromatin, because if we can begin to understand the way the DNA works and functions many other aspects will flow from that. I mentioned the cell’s surface, and I just want to impress on you the fact that the plasma membrane of a cell is much more complicated than was depicted in these drawings that I showed you just before.