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 Ceratium hirundinella, a dinoflagellate
 Clockwise from top-left: a haptophyte, some diatoms, a water mold, a cryptomonad, and Macrocystis, a phaeophyte
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Heterokontophyta
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Chromalveolata is a eukaryote supergroup first proposed by Thomas Cavalier-Smith as a refinement of his kingdom Chromista, which was first proposed in 1981. The dinoflagellates are a large group of Flagellate Protists Most are marine Plankton, but The haptophytes, classed either as the Prymnesiophyta or Haptophyta are a Phylum of Algae The Chloroplasts are pigmented similarly to those of the Diatoms ( Greek: (dia = "through" + (temnein = "to cut" i Oomycetes also known as Water molds (or water moulds: see spelling differences) are a group of filamentous unicellular Heterokonts physically The cryptomonads are a small group of Flagellates most of which have Chloroplasts They are common in freshwater and also occur in marine and brackish habitats Macrocystis is a genus of Kelp ( Algae) This genus contains the largest of all the Phaeophyceae or Brown algae. The Phaeophyceae or brown algae, (singular alga is a large group of mostly marine multicellular Algae including many Seaweeds of colder Animals Plants fungi, and Protists are eukaryotes (juːˈkærɪɒt or -oʊt Organisms whose cells are organized into complex Corticata ("one with a cortex" in the classification of Eukaryotes (living organisms with a cell nucleus is a Clade suggested by Cavalier-Smith Professor Thomas (Tom Cavalier-Smith (born October 21 1942) FRS, FRSC, NERC Professorial Fellow is a Professor of The heterokonts or stramenopiles are a major line of Eukaryotes presently containing about 10500 known species The haptophytes, classed either as the Prymnesiophyta or Haptophyta are a Phylum of Algae The Chloroplasts are pigmented similarly to those of the The cryptomonads are a small group of Flagellates most of which have Chloroplasts They are common in freshwater and also occur in marine and brackish habitats The alveolates ("with cavities" are a major line of Protists There are three phyla, which are very divergent in form but are now known to be close relatives The ciliates are one of the most important groups of Protists common almost everywhere there is water — lakes ponds oceans rivers and soils with many ectosymbiotic The dinoflagellates are a large group of Flagellate Protists Most are marine Plankton, but Animals Plants fungi, and Protists are eukaryotes (juːˈkærɪɒt or -oʊt Organisms whose cells are organized into complex Professor Thomas (Tom Cavalier-Smith (born October 21 1942) FRS, FRSC, NERC Professorial Fellow is a Professor of The Chromista are a eukaryotic supergroup probably Polyphyletic, As of 2006, it is often regarded as one of six major clades of eukaryotes,[1] although it is not yet clear whether it is indeed monophyletic[1][2]. A clade is a taxonomic group comprising a single Common ancestor and all the descendants of that ancestor It may be considered a “kingdom”, though it is not given any formal taxonomical classification. It comprises a line descending from a bikont which performed secondary endosymbiosis with a red alga, and it includes these four major groups:
Though several groups, such as the ciliates and the water molds, have lost the ability to photosynthesize, most are autotrophic. A Bikont ("two flagella" is a eukaryotic cell with two Flagella, as its name suggests An endosymbiont is any Organism that lives within the body or cells of another organism i The red algae (Rhodophyta ˌroʊdəˈfaɪtə roʊˈdɒfɨtə from Greek: ῥόδον (rhodon = rose + φυτόν (phyton = plant thus red plant are The heterokonts or stramenopiles are a major line of Eukaryotes presently containing about 10500 known species The haptophytes, classed either as the Prymnesiophyta or Haptophyta are a Phylum of Algae The Chloroplasts are pigmented similarly to those of the The cryptomonads are a small group of Flagellates most of which have Chloroplasts They are common in freshwater and also occur in marine and brackish habitats The alveolates ("with cavities" are a major line of Protists There are three phyla, which are very divergent in form but are now known to be close relatives The ciliates are one of the most important groups of Protists common almost everywhere there is water — lakes ponds oceans rivers and soils with many ectosymbiotic Oomycetes also known as Water molds (or water moulds: see spelling differences) are a group of filamentous unicellular Heterokonts physically An autotroph (from the Greek autos = self and trophe = nutrition is an Organism that produces complex Organic compounds from simple All photosynthetic chromalveolates use chlorophylls a and c, and many use accessory pigments. Chlorophyll is a green Pigment found in most Plants Algae and Cyanobacteria.
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Evolutionary relationship
Chromalveolata is part of the bikonts, which also comprise the Archaeplastida, the Rhizaria, the Excavata, and some smaller, unresolved groups such as the Apusozoa and the Centrohelida. The Archaeplastida or Primoplantae are a major line of Eukaryotes comprising the land plants green and Red algae and a small The Rhizaria are a species-rich supergroup of Protists They vary considerably in form but for the most part they are Amoeboids with filose reticulose or microtubule-supported The excavates are a major assemblage of Protists often known as Excavata. The Apusozoa comprise several genera of Flagellate protozoa They are usually around 5-20 μm in size and occur in soils and aquatic habitats where they feed on bacteria The centrohelids or centroheliozoa are a large group of Heliozoan protists As bikonts, they all descend from a heterotrophic eukaryote with two flagella. A heterotrophs, or chemoorganotrophy ( Greek heterone = (another and trophe = nutrition is an Organism that requires A flagellum ( plural flagella) is a tail-like structure that projects from the Cell body of certain Prokaryotic and Eukaryotic cells and it It is also thought that the Chromalveolata share a closer relationship with the Archaeplastida than with the other groups, and some have proposed a clade called Corticata for this grouping. Corticata ("one with a cortex" in the classification of Eukaryotes (living organisms with a cell nucleus is a Clade suggested by Cavalier-Smith
Historically, many chromalveolates were considered plants, with their cell walls, photosynthetic ability, and in some cases their morphological resemblance to the Embryophyta. Plants are living Organisms belonging to the kingdom Plantae. The embryophytes are the most familiar group of Plants They include Trees Flowers Ferns Mosses and various other green However, when the five-kingdom system took prevalence over the animal-plant dichotomy, most chromalveolates were put into the kingdom Protista, with the water molds and slime nets put into the kingdom Fungi, and the brown algae staying in the plant kingdom. Protists (ˈproʊtɨst are a diverse group of eukaryotic Microorganisms Historically protists were treated as the kingdom Protista but this Oomycetes also known as Water molds (or water moulds: see spelling differences) are a group of filamentous unicellular Heterokonts physically The Labyrinthulomycetes also known as Slime nets are a group of Protists that produce a network of filaments or Tubes, which serve as tracks for A fungus (ˈfʌŋgəs is a eukaryotic Organism that is a member of the kingdom Fungi (ˈfʌndʒaɪ The Phaeophyceae or brown algae, (singular alga is a large group of mostly marine multicellular Algae including many Seaweeds of colder After much research, Chromalveolata has been proposed as a monophyletic group, but the monophyly of this group is not yet established. [3][1]
Morphology
Chromalveolates, unlike other groups with multicellular representatives, do not have very many common morphological characteristics. Each major subgroup has certain unique features, including the alveoli of the Alveolata, the haptonema of the Haptophyta, the ejectisome of the Crytophyta, and the two different flagella of the Heterokontophyta. However, none of these features are present in all of the groups.
The only common chromalveolate features are these:
- The shared origin of chloroplasts, as mentioned above
- Presence of cellulose in most cell walls
Since this is such a diverse group, it is difficult to summarize shared chromalveolate characteristics. Cellulose is an Organic compound with the formula, a Polysaccharide consisting of a linear chain of several hundred to over ten thousand β(1→4
Ecological role
Many chromalveolates affect our ecosystem in enormous ways. Some of these organisms can be very harmful. Dinoflagellates produce red tides which can devastate fish populations and intoxicate oyster harvests. The dinoflagellates are a large group of Flagellate Protists Most are marine Plankton, but "Red tide" is a common name for a phenomenon known as an Algal bloom, an event in which estuarine marine or fresh water algae accumulate rapidly in the Water Apicomplexans are some of the most successful specific parasites to animals. Water molds cause several plant diseases. In fact, it was a water mold, Phytophthora infestans, that caused the Irish potato famine. Phytophthora infestans is an Oomycete that causes the serious Potato disease known as late blight or potato blight.
However, many chromalveolates are vital members of our ecosystem. Diatoms are one of the major photosynthetic producers, and produce much of the oxygen we breathe, and also take in much of the carbon dioxide that is thought to be a cause of global warming. Diatoms ( Greek: (dia = "through" + (temnein = "to cut" i Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Global warming is the increase in the average measured temperature of the Brown algae, most specifically kelps, create underwater "forest" habitats for many marine creatures, and provide a large portion of the diet of coastal communities. Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales
Chromalveolates also provide many products that we use. The algin in brown algae is used a food thickener, most famously in ice cream. Alginic acid ( algin, alginate) is a viscous gum that is abundant in the cell walls of Brown algae. Ice cream or ice-cream (originally iced cream) is a frozen dessert made from Dairy products such as Milk and Cream, combined The siliceous shells of diatoms have many uses, such as in reflective paint, in toothpaste, or as a filter, in what is known as diatomaceous earth.
References
- ^ a b c 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:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ Harper, J. T. , Waanders, E. & Keeling, P. J. 2005. On the monophyly of chromalveolates using a six-protein phylogeny of eukaryotes. Int. J. System. Evol. Microbiol. , 55, 487-496. [1]
- ^ Burki F, Shalchian-Tabrizi K, Minge M, Skjæveland Å, Nikolaev SI, et al. (2007). "Phylogenomics Reshuffles the Eukaryotic Supergroups". PLoS ONE 2 (8: e790): e790. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- Patron, N. J. , Rogers, M. B. and Keeling, P. J. 2004. Gene replacement of fructose-1,6-bisphophate aldolase supports the hypothesis of a single photosynthetic ancestor of chromalveolates. Eukaryot. Cell. 3, 1169-1174. [2]
- Harper, J. T. & Keeling, P. J. 2003. Nucleus-encoded, plastid-targeted glyceraldehyde-3-phosphate dehydrogenase (GAPDH) indicates a single origin for chromalveolate plastids. Mol. Biol. Evol. 20, 1730-1735.
- Archibald, J. M. & Keeling, P. J. 2002. Recycled plastids: a "green movement" in eukaryotic evolution. Trends Genet. , 18, 577-584.
- Fast, N. M. , Kissinger, J. C. , Roos, D. S. , & Keeling, P. J. 2001. Nuclear-encoded, plastid-targeted genes suggest a single common origin for apicomplexan and dinoflagellate plastids. Mol. Biol. Evol. , 18, 418-426.
- Cavalier-Smith, T. 1999. Principles of protein and lipid targeting in secondary symbiogenesis: Euglenoid, dinoflagellate, and sporozoan plastid origins and the eukaryote family tree. J. Eukaryot. Microbiol. 46:347–66.
Dictionary
chromalveolate
-noun
- (biology) A grouping of eukaryotes, of the taxon Chromalveolata, comprising the Chromista and the alveolates
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