Osmosis video - Nuclear structure

A cell's nucleus is a membrane-enclosed organelle found in eukaryotic cells, which serves as the control center of a cell. It contains the cell's genetic material in the form of DNA and directs the cell's activities. Inside the nucleus, there's also the nucleolus responsible for making ribosomes.

The nucleus has an outer membrane that consists of two layers: the inner and the outer layers. Nuclear pores run through the membrane and control the flow of molecules in and out of the nucleus.