- (anthropology) a structure found in the cell that contains the chromosomes.
- The very small, very dense, positively charged center of an atom containing protons and neutrons, as well as other subatomic particles.
- The small, central, positively charged region of an atom. Except for the nucleus of ordinary hydrogen, which has only a proton, all atomic nuclei contain both protons and neutrons. The number of protons determines the total positive charge or atomic number. This number is the same for all the atomic nuclei of a given chemical element. The total number of neutrons and protons is called the mass number.
Source: U.S. Nuclear Regulatory Commission
- (biology) central portion of a cell; specialized, central, and organized structure found in most cells containing the chromosomes
Source: Noland, George B. 1983. General Biology, 11th Edition. St. Louis, MO. C. V. Mosby
- (biotechnology) The membrane-bound region of a eukaryotic cell that contains the chromosomes.