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Difference between revisions of "Chromosome"

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[[Chromosome]]
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chromosome
  
(Science: [[cell]] biology) The self-replicating [[genetic]] [[structures]] of [[cells]] containing the [[cellular]] [[dna]] that [[bears]] in its [[nucleotide Sequence]] the [[linear]] array of [[genes]].
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''noun''
  
The [[dna]] of [[eukaryotes]] is subdivided into [[chromosomes]], that consist of a [[number]] of [[chromosomes]] whose [[dna]] is [[associated]] with various [[proteins]]. The [[chromosomes]] become more tightly packed at [[mitosis]] and become aligned on the [[metaphase plate]]. Each [[chromosome]] has a [[characteristic]] [[length]] and [[banding pattern]].
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It is a [[structure]] within the [[cell]] that bears the [[genetic material]] as a threadlike linear [[strand]] of [[DNA]] bonded to various [[proteins]] in the [[nucleus]] of [[eukaryotic]] [[cell]]s, or as a circular [[strand]] of [[DNA]] (or [[RNA]] in some [[virus]]es) in the [[cytoplasm]] of [[prokaryotes]] and in the [[mitochondrion]] and [[chloroplast]] of certain [[eukaryotes]].
  
in [[prokaryotes]], [[chromosomal]] [[dna]] is circular, and the [[entire]] [[genome]] is carried on one [[chromosome]].
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In [[eukaryotes]], the chromosomes appear as threadlike [[strand]] that [[condense]] into thicker [[structure]]s and aligns on the [[metaphase plate]] during [[mitosis]]. Humans normally have 23 pairs of chromosomes, each with a characteristic length and banding pattern. Chromosomes occur in pairs (in most [[somatic]] [[cell]]s) since one member of each pair comes from the mother and the other from the father. In most [[prokaryote]]s, the chromosome is usually a circular [[strand]] of [[DNA]]; hence, the entire [[genome]] is carried on only one chromosome. In [[virus]]es, the chromosome may appear as short linear or circular structure containing the [[DNA]] or [[RNA]] [[molecule]] often lacking any structural [[proteins]]
  
See: [[c banding]], [[g]] [[banding]].
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Word origin: from the Greek ''chroma'' = color + ''soma'' = body
A threadlike [[body]] in the [[cell]] [[nucleus]] that carries the [[genes]] in a [[linear]] order.The [[structures]] found within a [[cell]] that contain the [[genetic information]] of an [[organism]]. This [[genetic information]] is [[dna]] or [[mrna]], [[deoxyribonucleic acid]] and [[messenger]] [[ribonucleic acid]] respectively.
 

Revision as of 10:48, 26 April 2008

chromosome

noun

It is a structure within the cell that bears the genetic material as a threadlike linear strand of DNA bonded to various proteins in the nucleus of eukaryotic cells, or as a circular strand of DNA (or RNA in some viruses) in the cytoplasm of prokaryotes and in the mitochondrion and chloroplast of certain eukaryotes.

In eukaryotes, the chromosomes appear as threadlike strand that condense into thicker structures and aligns on the metaphase plate during mitosis. Humans normally have 23 pairs of chromosomes, each with a characteristic length and banding pattern. Chromosomes occur in pairs (in most somatic cells) since one member of each pair comes from the mother and the other from the father. In most prokaryotes, the chromosome is usually a circular strand of DNA; hence, the entire genome is carried on only one chromosome. In viruses, the chromosome may appear as short linear or circular structure containing the DNA or RNA molecule often lacking any structural proteins



Word origin: from the Greek chroma = color + soma = body