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Chromista

(Kingdom)

Overview

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The Chromista are a eukaryotic supergroup, probably polyphyletic,1][2] which may be treated as a separate kingdom or included among the Protista. They include all algae whose chloroplasts contain chlorophylls a and c, as well as various colorless forms that are closely related to them. These are surrounded by four membranes, and are believed to have been acquired from some red alga.

Groups

Chromista has been defined in different ways at different times.

It has been described as consisting of three different groups:[3]

In 2010, Thomas Cavalier-Smith indicated his desire to move Alveolata, Rhizaria and Heliozoa into Chromista.[4]

History and controversy

The name Chromista was first introduced by Cavalier-Smith in 1981;[5] the earlier names chromophyte and chromobiont correspond to roughly the same group. Molecular trees have had some difficulty resolving relationships between the different groups. All three may share a common ancestor with the alveolates (see chromalveolates), but there is evidence that suggests that the haptophytes and cryptomonads do not belong together with the heterokonts.[1][6]< /p>

See also

tp://mbe.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=18296415. 
  • ^ Cavalier-Smith T (June 2010). "Kingdoms Protozoa and Chromista and the eozoan root of the eukaryotic tree". Biol. Lett. 6 (3): 342?5. doi:10.1098/rsbl.2009.0948. PMC 2880060. PMID 20031978. http://rsbl.royalsocietypublishing.org/cgi/pmidlookup?view=long&pmid=20031978
  • ^ T. Cavalier-Smith (1981). "Eukaryote kingdoms: seven or nine?". Biosystems 14 (3?4): 461?481. doi:10.1016/0303-2647(81)90050-2. PMID 7337818
  • ^ Burki F, Shalchian-Tabrizi K, Minge M, et al (2007). Butler, Geraldine. ed. "Phylogenomics Reshuffles the Eukaryotic Supergroups". PLoS ONE 2 (8): e790. doi:10.1371/journal.pone.0000790. PMC 1949142. PMID 17726520. http://dx.plos.org/10.1371/journal.pone.0000790
  • External links

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    Taxonomy

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    The Kingdom Chromista is a member of the Domain Eukaryota. Here is the complete "parentage" of Chromista:

    The Kingdom Chromista is further organized into finer groupings including:

    Phyla

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    Chlorophyta

    Chlorophyta is a division of green algae, informally called chlorophytes. The name is used in two very different senses so that care is needed to determine the use by a particular author. In older classification systems, it refers to a highly paraphyletic group of all the green algae within the green plants (Viridiplantae), and thus includes about 7,000 species of mostly aquatic photosynthetic eukaryotic organisms. Like the land plants (bryophytes and tracheophytes), green algae contain chlorophylls a and b, and store food as starch in their plastids. [more]

    Cryptista

    [more]

    Cryptophyta

    The cryptomonads (or cryptophytes) are a group of algae, most of which have plastids. They are common in freshwater, and also occur in marine and brackish habitats. Each cell is around 10-50 ?m in size and flattened in shape, with an anterior groove or pocket. At the edge of the pocket there are typically two slightly unequal flagella. [more]

    Haptophyta

    The haptophytes, classified either as the Prymnesiophyta or Haptophyta, are a division of algae. [more]

    Hyphochytriomycota

    [more]

    Katablepharidophyta

    [more]

    Labyrinthulomycota

    [more]

    Ochrophyta

    Ochrophyta is a group of mostly photosynthetic heterokonts. It is divided into two subphyla, Phaeista (comprising Hypogyristea and Chrysista) and Khakista (comprising Bolidomonas and diatoms). [more]

    Oomycota

    O?mycota or o?mycetes form a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms. They are filamentous, microscopic, absorptive organisms that reproduce both sexually and asexually. Oomycetes occupy both saprophytic and pathogenic lifestyles ? and include some of the most notorious pathogens of plants, causing devastating diseases such as late blight of potato and sudden oak death. They are also often referred to as water molds (or water moulds), although the water-preferring nature which led to that name is not true of most species, which are terrestrial pathogens. [more]

    Opalozoa

    [more]

    Sarcodina

    Amoeboids are single-celled life-forms characterized by an irregular shape. [more]

    At least 1,458 species and subspecies belong to the Phylum Sarcodina.

    More info about the Phylum Sarcodina may be found here.

    References

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    1. ^ a b Laura Wegener Parfrey, Erika Barbero, Elyse Lasser, Micah Dunthorn, Debashish Bhattacharya, David J Patterson, and Laura A Katz (2006 December). "Evaluating Support for the Current Classification of Eukaryotic Diversity". PLoS Genet. 2 (12): e220. doi:10.1371/journal.pgen.0020220. PMC 1713255. PMID 17194223. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1713255
    2. ^ Cavalier-Smith T, Allsopp MT, Chao EE (November 1994). "Chimeric conundra: are nucleomorphs and chromists monophyletic or polyphyletic?". Proc. Natl. Acad. Sci. U.S.A. 91 (24): 11368?72. doi:10.1073/pnas.91.24.11368. PMC 45232. PMID 7972066. http://www.pubmedcentral.nih.gov/articleren der.fcgi?tool=pmcentrez&artid=45232
    3. ^ Csur?s M, Rogozin IB, Koonin EV (May 2008). "Extremely intron-rich genes in the alveolate ancestors inferred with a flexible maximum-likelihood approach". Mol. Biol. Evol. 25 (5): 903?11. doi:10.1093/molbev/msn039. PMID 18296415. http://mbe.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=18296415
    4. ^ Cavalier-Smith T (June 2010). "Kingdoms Protozoa and Chromista and the eozoan root of the eukaryotic tree". Biol. Lett. 6 (3): 342?5. doi:10.1098/rsbl.2009.0948. PMC 2880060. PMID 20031978. http://rsbl.royalsocietypublishing.org/cgi/pmidlookup?view=long&pmid=20031978
    5. ^ T. Cavalier-Smith (1981). "Eukaryote kingdoms: seven or nine?". Biosystems 14 (3?4): 461?481. doi:10.1016/0303-2647(81)90050-2. PMID 7337818
    6. ^ Burki F, Shalchian-Tabrizi K, Minge M, et al (2007). Butler, Geraldine. ed. "Phylogenomics Reshuffles the Eukaryotic Supergroups". PLoS ONE 2 (8): e790. doi:10.1371/journal.pone.0000790. PMC 1949142. PMID 17726520. http://dx.plos.org/10.1371/journal.pone.0000790

    Sources

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    Last Revised: August 24, 2012
    2012/08/24 12:57:34