nucleus definition

  • noun:
    • A central or important part around which other parts are gathered or grouped; a core: the nucleus of a city.
    • Something viewed as a basis for future development and development; a kernel: a couple of paintings that formed the nucleus of a good art collection.
    • Biology a sizable, membrane-bound, usually spherical protoplasmic structure within a full time income mobile, containing the mobile's genetic product and controlling its kcalorie burning, development, and reproduction.
    • Botany The main kernel of a nut or seed.
    • Botany The center of a starch granule.
    • Anatomy a team of specialized nerve cells or a localized mass of gray matter when you look at the brain or spinal cord.
    • Physics The positively billed central region of an atom, consists of protons and neutrons and containing almost all of the size regarding the atom.
    • Chemistry several atoms bound in a structure, like a benzene band, that is resistant to alteration in chemical responses.
    • Astronomy The main part of the top of a comet.
    • Astronomy The main or brightest section of a nebula or galaxy.
    • Meteorology A particle which water vapour molecules gather in free-air to form a droplet or ice crystal.
    • Linguistics The part of a syllable having the greatest sonority. In the term middlemost (mĭdˈl-mōstˌ) the nuclei associated with three syllables are (ĭ), (l), and (ō); inside Czech term krk ("neck”), the nucleus is (roentgen).
    • The core, main part (of one thing), round which other individuals tend to be assembled.
    • a preliminary part or variation that may receive improvements.
    • The massive, positively recharged central part of an atom, comprised of protons and neutrons.
    • a big organelle present cells which contains hereditary material.
    • A ganglion, cluster of numerous neuronal figures in which synapsing happens.
    • The central part of a syllable, most commonly a vowel.
    • A kernel; therefore, a central mass or point about which matter is collected, or to which accretion is made; the main or content part; -- used both literally and figuratively.
    • The body and/or mind of a comet.
    • An incipient ovule of smooth mobile structure.
    • an entire seed, as included within the seed coats.
    • A body, typically spheroidal, in a eukaryotic cellular, distinguished from the surrounding protoplasm by a significant difference in refrangibility as well as in behavior towards substance reagents, containing the chromosomal hereditary material, like the chromosomal DNA. It is more or less protoplasmic, and is comprised of a clear liquid (achromatin) through which stretches a network of fibers (chromatin) which could be suspended a moment rounded human anatomy, the nucleolus (see Nucleoplasm). See Cell unit, under Division.
    • the end, or very first part, of a univalve or bivalve layer.
    • The central component around which additional growths tend to be included, since an operculum.
    • A visceral mass, containing the belly along with other body organs, in Tunicata many mollusks.
    • A kernel; therefore, a main mass about which matter is gathered, or even to which accretion is made; any body or thing that serves as a center of aggregation or assemblage; figuratively, something current as a short or center point or aggregate: because, a nucleus of truth; a nucleus of civilization.
    • In biology, the kernel of a cell, as a whole; a central or interior differentiated mass of protoplasm, present most cells, veggie or pet, and consisting of an oval or curved human body consists of
    • a nuclear membrane layer
    • nuclear system, and
    • nucleoplasm, and containing nucleoli. The nuclear network is made up of threads or fibrils which are composed of a deeply staining part, “chromatin,” and a feebly staining intermediate substance, “linin” or parachromatin (nucleohyaloplasm). In the meshes of the network is found the more fluid part of the nucleus, the nucleoplasm (achromatin, karyochylema, paralinin). Nucleoplasm, according to Carnoy, consists of a plastin network and a granular fluid, “enchylema.” The nuclear membrane is considered by some observers to be an inner limiting layer of cell-protoplasm surrounding the nucleus, by others to be a condensation of the peripheral portion of the nuclear network. There may be but one nucleus or several nuclei in one cell; and a nucleus may be nucleolate or not. Nuclei are generally proportionate in size to the cell containing them: in some instances, however, they form almost the entire cell mass. A structural difference between the nucleus and the rest of the cell-protoplasm is indicated by its greater resistance to powerful reagents, and by its varied reaction with stains. Functionally, the nucleus is the most important portion of the cell, as it is here that the complex series of changes known as karyokinesis take place, resulting in the division of the nucleus and followed by the division of the cell. This process of mitosic or indirect cell-division is found in all varieties of cells, whether vegetable or animal, fetal or adult, normal or pathological. Instances of cell-division not mitosic have, however, been noted. The nucleus of the human ovum was discovered by Purkinje in 1825, and hence is often called the corpuscle of Purkinje. Its usual name in text-books of anatomy is germinal vesicle. See cut under cell, 5.
    • In zoology:
    • In ascidians, the alimentary and reproductive viscera collectively, whenever they're aggregated into a mass, as with the salps.
    • In protozoans, a great rod-like or strap-shaped human anatomy, having most of the time the functions of an ovary in connection with a nucleolus (see nucleolus, 2).
    • In echinoderms, the madreporiform body
    • In anatomy, an accumulation of ganglion-cells inside mind or other part of the cerebrospinal axis.
    • In conchology, the embryonic shell which continues to be during the apex of the mature layer, as of a gastropod; additionally, the first point where the operculum of a gastropod develops. See protoconch.
    • A body having a stronger or weaker attraction for the gas, vapor, or salt of a solution than for the liquid part of it, and therefore modifying by its presence the freezing-and boiling-points.
    • In astronomy, the brilliant central point usually present in your head of a comet and frequently in a nebula.
    • A genus of gastropods: identical to Columbella.
    • just like claustrum, 1.
    • a rather small colony of honey-bees started for the true purpose of rearing queens to switch with all the queens of complete colonies, therefore helping inside avoidance of swarming.
    • no points after all;
    • a perfect set. This result (set) is the nucleus EΩ.
    • the positively charged heavy center of an atom
    • any histologically identifiable size of neural cell systems inside mind or back
    • (astronomy) the middle of the top of a comet; comes with little solid particles of ice and frozen fuel that vaporizes on approaching the sun's rays to create the coma and tail
    • part of the mobile containing DNA and RNA and responsible for growth and reproduction
    • the main construction of this lens which in the middle of the cortex
    • a small band of essential people or things

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