The nucleoli

In the phase that the eukaryotic cell is not in division, it is possible to visualize several nucleoli, associated to some specific regions of the chromatin.

Each nucleolus is a spongy, non-membranous corpuscle of spongy appearance when viewed under the electron microscope, rich in ribosomal RNA (Acronym for RNA comes from English RiboNucleic THEcid).

This RNA is a nucleic acid produced from the DNA of specific chromatin regions and will constitute one of the major components of ribosomes present in the cytoplasm.

It is important to realize that when chromosomal spiraling occurs the nucleoli slowly disappear. This happens during the events that characterize cell division. Nucleoli reappear with chromosome de-spiralization at the end of nucleus division.