Nucleolus? Kernkцrperchen? Definition:

Of the nucleolus (lat. nucleolus = kernel) or the Kernkцrperchen (alternative name) are located inside the nucleus and are involved in the production of subunits of the ribosomes. In a nuclear body ribosomes are produced and transported through nuclear pores in a cell. In the course of protein biosynthesis, the ribosomes function as a site for translation.
The structure of roundish nuclear bodies can change during different stages of cell division. Under the microscope, the nuclear bodies can be seen especially during prometaphase (mitosis). At this stage, the core hull dissolves.

Structure of the nucleolus

Upon closer inspection of the nuclear body under the microscope, essentially two different structures emerge. These are the ones Pars granulosa and as Pars fibrosa designated sub-elements:
1.) In pars fibrosa, rRNA is transcribed into ribosomal proteins.
2.) In the pars granulosa, the ribosobal proteins are further processed to Prd ribosomes
Main constituents of the nuclear bodies are therefore ribonucleic acids (RNA) and ribosomal proteins. That RNA is the basis for the nuclear synthesis of the subordinate ribosomal cell units.
Furthermore, the pars fibrosa can be further subdivided into "dense fibrillar" and "fibrillated" units.

Function of the nucleolus

The enormous importance of nuclear bodies can be understood by their participation in cell division. In both animal and plant cell networks, the nucleolus takes over the production of prd ribosomes. This means that certain basic processes for the synthesis of the ribosomes and their further maturation in the nucleoli take place. In short, the nuclear bodies are the "production sites" of the ribosomes and thus indispensable for protein biosynthesis.