Difference between revisions of "Nucleus"

From Biology-Online Dictionary | Biology-Online Dictionary
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nucleus
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'''Definition'''
  
''noun''
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''noun, plural: nuclei''
  
In general, a nucleus is the [[core]] or the central part around which other parts are grouped or gathered.
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The [[core]] or the central part around which other parts are grouped or gathered.
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'''Supplement'''
  
 
In '''Biology''', a nucleus is the large, membrane-bounded [[organelle]] that contains the [[genetic material]], in the form of [[multiple]] [[linear]] [[DNA]] [[molecule]]s organized into [[structure]]s called [[chromosomes]]. Its major functions are to maintain the integrity of [[DNA]] and to control cellular activities such as [[metabolism]], [[growth]], and [[reproduction]] by regulating gene expression. It has three main components: the [[nucleolus]], the [[chromatin]] and the [[nuclear envelope]]. The [[nuclear envelope]] has [[nuclear pore]]s to control the [[movement]] of [[molecule]]s between the nucleoplasm and the [[cytoplasm]].  
 
In '''Biology''', a nucleus is the large, membrane-bounded [[organelle]] that contains the [[genetic material]], in the form of [[multiple]] [[linear]] [[DNA]] [[molecule]]s organized into [[structure]]s called [[chromosomes]]. Its major functions are to maintain the integrity of [[DNA]] and to control cellular activities such as [[metabolism]], [[growth]], and [[reproduction]] by regulating gene expression. It has three main components: the [[nucleolus]], the [[chromatin]] and the [[nuclear envelope]]. The [[nuclear envelope]] has [[nuclear pore]]s to control the [[movement]] of [[molecule]]s between the nucleoplasm and the [[cytoplasm]].  
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''In other fields, such as:''
 
''In other fields, such as:''
  
''In Physics, a nucleus refers to the positively-charged center of an [[atom]] that usually contains the [[proton]]s and [[neutron]]s.''
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In Physics, a nucleus refers to the positively-charged center of an [[atom]] that usually contains the [[proton]]s and [[neutron]]s.
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In Chemistry, a nucleus is a fundamental arrangement of [[atom]]s that occur in [[compound]]s through [[substitution]] of [[atom]]s without a change in [[structure]].
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In Astronomy, a nucleus is the center of the [[head]] of a comet or the central or brightest part of a [[nebula]] or [[galaxy]].
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In Meteorology, a nucleus is a [[particle]] on which water vapor [[molecule]]s accumulate in free [[air]] to form water drops or ice crystals.
  
''In Chemistry, a nucleus is a fundamental arrangement of [[atom]]s that occur in [[compound]]s through [[substitution]] of [[atom]]s without a change in [[structure]].''
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In Botany, a nucleus is the central [[kernel]] of a [[nut]] or [[seed]], or the center of a [[starch]] [[granule]].
  
''In Astronomy, a nucleus is the center of the [[head]] of a comet or the central or brightest part of a [[nebula]] or [[galaxy]].''
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In Anatomy, a nucleus is a group of specialized [[nerve cell]]s in the [[brain]] or [[spinal cord]].
  
''In Meteorology, a nucleus is a [[particle]] on which water vapor [[molecule]]s accumulate in free [[air]] to form water drops or ice crystals.''
 
  
''In Botany, a nucleus is the central [[kernel]] of a [[nut]] or [[seed]], or the center of a [[starch]] [[granule]].''
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''Word origin:'' L: kernel, syncopated var. of nuculeus, equiv. to nucu(la) little nut (nuc-, s. of nux nut + -ula -ULE) + -leus n. suffix.
  
''In Anatomy, a nucleus is a group of specialized [[nerve cell]]s in the [[brain]] or [[spinal cord]].''
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<br>''Related forms:'' nuclear (''adjective'').

Revision as of 01:05, 13 July 2008

Definition

noun, plural: nuclei

The core or the central part around which other parts are grouped or gathered.


Supplement

In Biology, a nucleus is the large, membrane-bounded organelle that contains the genetic material, in the form of multiple linear DNA molecules organized into structures called chromosomes. Its major functions are to maintain the integrity of DNA and to control cellular activities such as metabolism, growth, and reproduction by regulating gene expression. It has three main components: the nucleolus, the chromatin and the nuclear envelope. The nuclear envelope has nuclear pores to control the movement of molecules between the nucleoplasm and the cytoplasm.

In other fields, such as:

In Physics, a nucleus refers to the positively-charged center of an atom that usually contains the protons and neutrons.

In Chemistry, a nucleus is a fundamental arrangement of atoms that occur in compounds through substitution of atoms without a change in structure.

In Astronomy, a nucleus is the center of the head of a comet or the central or brightest part of a nebula or galaxy.

In Meteorology, a nucleus is a particle on which water vapor molecules accumulate in free air to form water drops or ice crystals.

In Botany, a nucleus is the central kernel of a nut or seed, or the center of a starch granule.

In Anatomy, a nucleus is a group of specialized nerve cells in the brain or spinal cord.


Word origin: L: kernel, syncopated var. of nuculeus, equiv. to nucu(la) little nut (nuc-, s. of nux nut + -ula -ULE) + -leus n. suffix.


Related forms: nuclear (adjective).