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ID: 2001
User: 71.138.215.100
Article: Chloroplast
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m (Reverted edits by 24.21.134.122 (talk) to last version by I dream of horses)
(Evolutionary origin)
(Tag: possible vandalism)
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==Evolutionary origin==
 
==Evolutionary origin==
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When I was 4 years old I got shot by a gangster. Your mom is a hooker. <ref>{{cite journal |author= Joyard J Block MA, Douce R|title=Molecular aspects of plastid envelope biochemistry. |journal=Eur J Biochem. |volume=199 |pages=489–509 |year=1991 |pmid=1868841 |doi= 10.1111/j.1432-1033.1991.tb16148.x |issue= 3}}</ref> Chloroplasts have their own genome, which is considerably [[genome reduction|reduced]] compared to that of free-living cyanobacteria, but the parts that are still present show clear similarities with the cyanobacterial genome. Plastids may contain 60-100 genes whereas cyanobacteria often contain more than 1500 genes.<ref>{{cite journal |author=Martin W, Rujan T, Richly E |title=Evolutionary analysis of Arabidopsis, cyanobacterial, and chloroplast genomes reveals plastid phylogeny and thousands of cyanobacterial genes in the nucleus |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=99 |issue=19 |pages=12246–51 |year=2002 |month=September |pmid=12218172 |pmc=129430 |doi=10.1073/pnas.182432999 |url=http://www.pnas.org/cgi/pmidlookup?view=long&pmid=12218172}}</ref> Many of the missing genes are encoded in the nuclear genome of the host. The transfer of nuclear information has been estimated in [[tobacco]] plants at one [[gene]] for every 16000 pollen grains.<ref>{{cite journal |author=Huang CY, Ayliffe MA, Timmis JN |title=Direct measurement of the transfer rate of chloroplast DNA into the nucleus |journal=Nature |volume=422 |issue=6927 |pages=72–6 |year=2003 |month=March |pmid=12594458 |doi=10.1038/nature01435 }}</ref>
[[File:Plagiomnium affine laminazellen.jpeg|thumb|250px|Chloroplasts visible in the cells of ''[[Plagiomnium affine]]'' — Many-fruited Thyme-moss]]
 
[[File:Überseemuseum Bremen 2009 238.JPG|thumb|right|250px|A model chloroplast]]
 
Chloroplasts are one of the many different types of organelles in the plant cell. In general, they are considered to have originated from [[cyanobacteria]] through [[endosymbiotic theory|endosymbiosis]]. This was first suggested by [[Konstantin Mereschkowski|Mereschkowsky]] in 1905<ref>{{cite journal | author= Mereschkowsky C | title= Über Natur und Ursprung der Chromatophoren im Pflanzenreiche | journal= Biol Centralbl | year=1905 | volume=25 | pages=593–604}}</ref> after an observation by [[Andreas Franz Wilhelm Schimper|Schimper]] in 1883 that chloroplasts closely resemble cyanobacteria.<ref>{{cite journal | author= Schimper AFW | title= Über die Entwicklung der Chlorophyllkörner und Farbkörper | journal= Bot. Zeitung | year=1883 | volume=41 | pages=105–14, 121–31, 137–46, 153–62}}</ref> All chloroplasts are thought to derive directly or indirectly from a single endosymbiotic event (in the [[Archaeplastida]]), except for ''[[Paulinella]] chromatophora'', which has recently acquired a photosynthetic cyanobacterial endosymbiont which is not closely related to chloroplasts of other eukaryotes.<ref>{{cite journal | title = Diversity and evolutionary history of plastids and their hosts | author = Patrick J. Keeling | url = http://www.amjbot.org/cgi/content/full/91/10/z1481 | journal = American Journal of Botany | year = 2004 | volume = 91 | pages = 1481–1493 | doi = 10.3732/ajb.91.10.1481 | format = {{dead link|date=July 2010}}}}</ref> In that they derive from an endosymbiotic event, chloroplasts are similar to [[mitochondrion|mitochondria]], but chloroplasts are found only in [[plant]]s and [[protist]]a. The chloroplast is surrounded by a double-layered composite membrane with an intermembrane space; further, it has reticulations, or many infoldings, filling the inner spaces. The chloroplast has its own [[DNA]],<ref>C.Michael Hogan. 2010. [http://www.eoearth.org/articles/view/158858/?topic=49496 ''Deoxyribonucleic acid''. Encyclopedia of Earth. National Council for Science and the Environment.] eds. S.Draggan and C.Cleveland. Washington DC</ref> which codes for redox proteins involved in electron transport in photosynthesis; this is termed the [[plastome]].<ref>{{cite journal |author=Krause K |title=From chloroplasts to "cryptic" plastids: evolution of plastid genomes in parasitic plants |journal=Curr. Genet. |volume=54 |issue=3 |pages=111–21 |year=2008 |month=September |pmid=18696071 |doi=10.1007/s00294-008-0208-8}}</ref>
 
 
In green plants, chloroplasts are surrounded by two [[cell membrane|lipid-bilayer membrane]]s. They are believed to correspond to the outer and inner membranes of the ancestral cyanobacterium.<ref>{{cite journal |author= Joyard J Block MA, Douce R|title=Molecular aspects of plastid envelope biochemistry. |journal=Eur J Biochem. |volume=199 |pages=489–509 |year=1991 |pmid=1868841 |doi= 10.1111/j.1432-1033.1991.tb16148.x |issue= 3}}</ref> Chloroplasts have their own genome, which is considerably [[genome reduction|reduced]] compared to that of free-living cyanobacteria, but the parts that are still present show clear similarities with the cyanobacterial genome. Plastids may contain 60-100 genes whereas cyanobacteria often contain more than 1500 genes.<ref>{{cite journal |author=Martin W, Rujan T, Richly E |title=Evolutionary analysis of Arabidopsis, cyanobacterial, and chloroplast genomes reveals plastid phylogeny and thousands of cyanobacterial genes in the nucleus |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=99 |issue=19 |pages=12246–51 |year=2002 |month=September |pmid=12218172 |pmc=129430 |doi=10.1073/pnas.182432999 |url=http://www.pnas.org/cgi/pmidlookup?view=long&pmid=12218172}}</ref> Many of the missing genes are encoded in the nuclear genome of the host. The transfer of nuclear information has been estimated in [[tobacco]] plants at one [[gene]] for every 16000 pollen grains.<ref>{{cite journal |author=Huang CY, Ayliffe MA, Timmis JN |title=Direct measurement of the transfer rate of chloroplast DNA into the nucleus |journal=Nature |volume=422 |issue=6927 |pages=72–6 |year=2003 |month=March |pmid=12594458 |doi=10.1038/nature01435 }}</ref>
 
   
 
In some algae (such as the [[heterokont]]s and other protists such as [[Euglenozoa]] and [[Cercozoa]]), chloroplasts seem to have evolved through a secondary event of endosymbiosis, in which a eukaryotic cell engulfed a second eukaryotic cell containing chloroplasts, forming chloroplasts with three or four membrane layers. In some cases, such secondary [[endosymbiont]]s may have themselves been engulfed by still other eukaryotes, thus forming tertiary endosymbionts. In the alga ''[[Chlorella]]'', there is only one chloroplast, which is bell-shaped.
 
In some algae (such as the [[heterokont]]s and other protists such as [[Euglenozoa]] and [[Cercozoa]]), chloroplasts seem to have evolved through a secondary event of endosymbiosis, in which a eukaryotic cell engulfed a second eukaryotic cell containing chloroplasts, forming chloroplasts with three or four membrane layers. In some cases, such secondary [[endosymbiont]]s may have themselves been engulfed by still other eukaryotes, thus forming tertiary endosymbionts. In the alga ''[[Chlorella]]'', there is only one chloroplast, which is bell-shaped.
Reason: ANN scored at 1
Reporter Information
Reporter: Anonymous (anonymous)
Date: Wednesday, the 21st of February 2018 at 03:24:38 AM
Status: Reported
Wednesday, the 21st of February 2018 at 03:24:38 AM #110659
Anonymous (anonymous)

I did it as a joke and really wish for it to deleted

Thursday, the 29th of March 2018 at 04:45:09 AM #111002
Huracan259

I DON'TDO IT

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