Found 2 items, similar to Nuclei.
English → English (WordNet) Definition: nuclei nucleus n 1: a part of the cell containing DNA and RNA and responsible for growth and reproduction [syn: cell nucleus, karyon] 2: the positively charged dense center of an atom 3: a small group of indispensable persons or things; “five periodicals make up the core of their publishing program” [syn: core, core group] 4: (astronomy) the center of the head of a comet; consists of small solid particles of ice and frozen gas that vaporizes on approaching the sun to form the coma and tail 5: any histologically identifiable mass of neural cell bodies in the brain or spinal cord [also: nuclei (pl)] nuclei See nucleus
English → English (gcide) Definition: Nuclei Nucleus \Nu"cle*us\, n.; pl. E. Nucleuses, L. Nuclei. [L., a kernel, dim. fr. nux, nucis, nut. Cf. Newel post.] [1913 Webster] 1. A kernel; hence, a central mass or point about which matter is gathered, or to which accretion is made; the central or material portion; -- used both literally and figuratively. [1913 Webster] It must contain within itself a nucleus of truth. --I. Taylor. [1913 Webster] 2. (Astron.) The body or the head of a comet. [1913 Webster] 3. (Bot.) (a) An incipient ovule of soft cellular tissue. (b) A whole seed, as contained within the seed coats. [1913 Webster] 4. (Biol.) A body, usually spheroidal, in a eukaryotic cell, distinguished from the surrounding protoplasm by a difference in refrangibility and in behavior towards chemical reagents, which contains the chromosomal genetic material, including the chromosomal DNA. It is more or less protoplasmic, and consists of a clear fluid (achromatin) through which extends a network of fibers (chromatin) in which may be suspended a second rounded body, the nucleolus (see Nucleoplasm). See Cell division , under Division. [1913 Webster +PJC] Note: The nucleus is sometimes termed the endoplast or endoblast, and in the protozoa is supposed to be concerned in the female part of the reproductive process. See Karyokinesis. [1913 Webster] 5. (Zo["o]l.) (a) The tip, or earliest part, of a univalve or bivalve shell. (b) The central part around which additional growths are added, as of an operculum. (c) A visceral mass, containing the stomach and other organs, in Tunicata and some mollusks. [1913 Webster]