Peering deep into the cell to reveal essential components in cell division
(PHYSorg.com Biology)

The cell is the basic biological unit of all known living organisms, and the core of the cell is the nucleus, which contains the majority of the cell`s genetic material. The largest structure in the nucleus of eukaryotic cells is the nucleolus. It is best known as the site of production of ribosome-the `factory` for protein production. The nucleolus also plays a role in the cell`s response to stress and is tightly connected to cell cycle progression.