Definitions for "Nucleolar organizer"
Keywords:  nucleolus, ribosomal, rrna, rna, tandem
Region of a chromosome containing a cluster of ribosomal RNA genes that gives rise to a nucleolus.
A region on a chromosome that is associated with formation of a new nucleolus following cell division. It contains the genes for several species of ribosomal RNA (rRNA), i.e., 18S, 5.8S, 5S and 28S in eukaryotes. Nucleolus: The site of synthesis of rRNA within the nucleus of a eukaryotic cell.
(NO); nucleolar organizer region (NOR)  A chromosomal segment containing genes that encode ribosomal RNA; located at the secondary constriction of some chromosomes.