Definition of lackey - a servant, especially a liveried footman or manservant, a brownish European moth of woods and hedgerows, the caterpillars of which Definition of lackey - a servant, especially a liveried footman or manservant, a brownish European moth of woods and hedgerows, the caterpillars of which
The nucleolus is the nuclear subdomain that assembles ribosomal subunits in eukaryotic cells. The nucleolar organiser regions of chromosomes, which contain the genes for preâribosomal ribonucleic acid (rRNA), serve as the foundation for nucleolar structure.
Through the microscope, the nucleolus looks like a large dark spot within the nucleus. A nucleus may contain up to four nucleoli, but within each species the number of nucleoli is fixed. After a cell divides, a nucleolus is formed when chromosomes are brought together into nucleolar organizing regions. During cell division, the nucleolus disappears. Some studies suggest that the nucleolus may be involved with cellular aging and, therefore, may affect the senescence of an organism.