Meaning of Nucleolus

What is Nucleolus:

The nucleolus or nucleolus is called essential region of the nucleus of eukaryotic cells that is involved in the formation of ribosomes. A large part of animal and plant cells have one or more nucleoli.

The nucleolus is characterized by being a spheroidal organelle, considered a supra-macromolecular structure, which does not have a limiting membrane and is composed of proteins and RNA.


On the other hand, the nucleolus is responsible for making ribosome subunits that contain proteins and ribosomal RNAwhich will be sent to the rest of the cell so that they become complete ribosomes.

Also the nucleolus has an important role in the elaboration of proteins in the cell.

See also cell nucleus.

nucleolus function

The main function of the nucleolus is the biosynthesis of ribosomes. from the DNA components to form ribosomal RNA (rRNA) through polymerase I, and the subsequent processing and assembly of the components that will form new ribosomes. This function is related to protein synthesis.

The nucleolus is also responsible for transporting small portions of RNA and participates in its maturation until it reaches the cell.

In addition, recent research has described the nucleolus as being responsible for regulating the cell cycle, although it disappears during the division process.

Therefore, it has been determined that the nucleolus is multifunctional thanks to its complex composition (protein, RNA), which has even led, due to its close relationship with the chromosomal matter of the cell, to be considered the cause of different human diseases.

See also animal cell.

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parts of nucleolus

The structure of the nucleolus can be seen through an electron microscope, hence the following parts are distinguished:

Density: the nucleolus is the most prominent part of the nucleus due to the difference in density it has with the chromatin in which it is located and that can be observed using a microscope. Generally, it has a spherical shape.

Nucleoplasm: they are the interconnected cavities in the dense part of the nucleolus; contains DNA granules.

Nucleonema: three parts are distinguished that are the granular part, the fibrillar part and the fibrillar center.

See also RNA.