The dense, bright and spherical material seen inside the nucleus is called nucleolus. Each nucleolus consists of three parts. Pars Amorpha, Nucleonima and Matrika. The surrounding part of the nucleolus is called pars amorpha, the central part is called nucleonema and the liquid part inside is called matrix. It is attached to a chromosome called the organizer. The location of the chromosome where the nucleolus is attached is called the SAT or satellite. Nucleolus contains DNA, RNA, proteins, lipids, enzymes, phosphorus, sulphur, potassium etc. In 1781, the scientist Felice Fontana first observed the nucleolus. Nucleolus was named by Bowman in 1840. The SAT gene located on the satellite of the chromosome plays a direct role in the production of nucleolus. Cells that do not synthesize proteins do not have a nucleolus. Spermatozoa, red blood cells and white blood cells do not contain nucleolus.
Function: Nucleolus synthesizes different types of RNA. It synthesizes and stores proteins. It acts as a storehouse of nucleotides. It creates ribosomes.