NUCLEUS (nuclei)

Pronunciation (US):

(GB):

IPA (US):

Irregular inflected form: nuclei   

 Dictionary entry overview: What does nucleus mean? 

• NUCLEUS (noun)
  The noun NUCLEUS has 6 senses:

1. a part of the cell containing DNA and RNA and responsible for growth and reproduction

2. the positively charged dense center of an atom

3. a small group of indispensable persons or things

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

6. the central structure of the lens that is surrounded by the cortex

  Familiarity information: NUCLEUS used as a noun is common.

 Dictionary entry details 

• NUCLEUS (noun)

Sense 1

Meaning:

A part of the cell containing DNA and RNA and responsible for growth and reproduction

Classified under:

Nouns denoting body parts

Synonyms:

cell nucleus; karyon; nucleus

Hypernyms ("nucleus" is a kind of...):

cell organ; cell organelle; organelle (a specialized part of a cell; analogous to an organ)

Meronyms (parts of "nucleus"):

nucleole; nucleolus (a small round body of protein in a cell nucleus; such organelles contain RNA and are involved in protein synthesis)

chromatin; chromatin granule (the readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins; during mitotic division it condenses into chromosomes)

achromatin (the part of a cell nucleus that is relatively uncolored by stains or dyes)

linin (an obsolete term for the network of viscous material in the cell nucleus on which the chromatin granules were thought to be suspended)

chromosome (a threadlike strand of DNA in the cell nucleus that carries the genes in a linear order)

Meronyms (substance of "nucleus"):

karyoplasm; nucleoplasm (the protoplasm that constitutes the nucleus of a cell)

Hyponyms (each of the following is a kind of "nucleus"):

pronucleus (the nucleus of the ovum or sperm after fertilization but before they fuse to form the nucleus of the zygote)

subthalamic nucleus (an oval mass of grey matter located in the caudal part of the subthalamus; associated with the striate body)

Holonyms ("nucleus" is a part of...):

cell ((biology) the basic structural and functional unit of all organisms; they may exist as independent units of life (as in monads) or may form colonies or tissues as in higher plants and animals)

Derivation:

nucleate (form into a nucleus)

Sense 2

Meaning:

The positively charged dense center of an atom

Classified under:

Nouns denoting natural objects (not man-made)

Hypernyms ("nucleus" is a kind of...):

center; centre; midpoint (a point equidistant from the ends of a line or the extremities of a figure)

Meronyms (parts of "nucleus"):

nucleon (a constituent (proton or neutron) of an atomic nucleus)

Holonyms ("nucleus" is a part of...):

atom ((physics and chemistry) the smallest component of an element having the chemical properties of the element)

Sense 3

Meaning:

A small group of indispensable persons or things

Classified under:

Nouns denoting groupings of people or objects

Synonyms:

core; core group; nucleus

Context example:

five periodicals make up the core of their publishing program

Hypernyms ("nucleus" is a kind of...):

set (a group of things of the same kind that belong together and are so used)

Hyponyms (each of the following is a kind of "nucleus"):

cadre (a nucleus of military personnel capable of expansion)

Sense 4

Meaning:

(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

Classified under:

Nouns denoting natural objects (not man-made)

Hypernyms ("nucleus" is a kind of...):

center; centre; midpoint (a point equidistant from the ends of a line or the extremities of a figure)

Domain category:

astronomy; uranology (the branch of physics that studies celestial bodies and the universe as a whole)

Holonyms ("nucleus" is a part of...):

comet ((astronomy) a relatively small extraterrestrial body consisting of a frozen mass that travels around the sun in a highly elliptical orbit)

Sense 5

Meaning:

Any histologically identifiable mass of neural cell bodies in the brain or spinal cord

Classified under:

Nouns denoting body parts

Hypernyms ("nucleus" is a kind of...):

neural structure (a structure that is part of the nervous system)

Hyponyms (each of the following is a kind of "nucleus"):

dentate nucleus (a large laminar nucleus of grey matter within the white matter of each cerebral hemisphere)

Sense 6

Meaning:

The central structure of the lens that is surrounded by the cortex

Classified under:

Nouns denoting body parts

Synonyms:

lens nucleus; nucleus

Hypernyms ("nucleus" is a kind of...):

anatomical structure; bodily structure; body structure; complex body part; structure (a particular complex anatomical part of a living thing and its construction and arrangement)

 Context examples 

An autoimmune antibody that is directed against structures within the nucleus of the cell.

(Antinuclear Antibody, NCI Thesaurus)

A nucleus that is located in the olfactory tract.

(Anterior Olfactory Nucleus, NCI Thesaurus)

The period of greatest risk to orbiting spacecraft will start about 90 minutes later and last about 20 minutes, when Mars will come closest to the center of the widening dust trail from the nucleus.

(Mars spacecraft prepare for close comet flyby, NASA)

There’s a subtle relationship between the mitochondria and nuclei in our cells that we’re only just starting to understand.

(Interplay between mitochondria and the nucleus may have implications for changing cell’s ‘batteries’, University of Cambridge)

The malignant cells that line the vascular channels are spindle or epithelioid and often display hyperchromatic nuclei.

(Angiosarcoma, NCI Thesaurus)

Anaplastic carcinoma cells have large hyperchromatic nuclei and display marked variation in nuclear size and shape, and high mitotic rate.

(Anaplastic Carcinoma Cell, NCI Thesaurus)

Of course it is a nucleus and focus of crime.

(The Adventures of Sherlock Holmes, by Sir Arthur Conan Doyle)

Cadherin may acts as a negative regulator of signaling beta-catenin as it binds beta-catenin at the cell surface and thereby sequesters it from the nucleus.

(Adherens Junction Assembly Pathway, NCI Thesaurus/KEGG)

Aldosterone enters a target cell and binds MR, which translocates into the nucleus and regulates gene transcription.

(Aldosterone-Regulated Sodium Reabsorption Pathway, NCI Thesaurus/KEGG)

Activation of Wnt signaling inhibits GSK3, thereby preventing phosphorylation of b-catenin, which is then able to move to the nucleus.

(ALK Pathway, NCI Thesaurus/BIOCARTA)