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Brown algae
Pacific rockweed (Fucus distichus) in Olympic National Park
Pacific rockweed (Fucus distichus) in Olympic National Park
Scientific classification
Domain: Eukaryota
Kingdom: Chromalveolata
Phylum: Heterokontophyta
Class: Phaeophyceae
Kjellman

The Phaeophyceae or brown algae, (singular: alga) is a large group of mostly marine multicellular algae, including many seaweeds of colder Northern Hemisphere waters. Olympic National Park is located in the US state of Washington, in the Olympic Peninsula. Animals Plants fungi, and Protists are eukaryotes (juːˈkærɪɒt or -oʊt Organisms whose cells are organized into complex Chromalveolata is a Eukaryote supergroup first proposed by Thomas Cavalier-Smith as a refinement of his kingdom Chromista, which was first The heterokonts or stramenopiles are a major line of Eukaryotes presently containing about 10500 known species Frans Reinhold Kjellman ( 4 November 1846 &ndash 22 April 1907) was a Swedish Botanist who specialized in Marine phycology An ocean (from Greek, ''Okeanos'' (Oceanus) is a major body of saline water, and a principal component of the Hydrosphere. Algae ( sing. alga are a large and diverse group of simple typically Autotrophic organisms ranging from Unicellular to Multicellular forms Seaweed is a loose colloquial term encompassing macroscopic Multicellular, benthic marine Algae. Northern Hemisphere is the half of a Planet that is North of the Equator —the word hemisphere literally means 'half ball' They play an important role in marine environments both as food, and for the habitats they form. For instance Macrocystis, a member of the Laminariales or kelps, may reach 60 m in length, and forms prominent underwater forests. Macrocystis is a genus of Kelp ( Algae) This genus contains the largest of all the Phaeophyceae or Brown algae. Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales The metre or meter is a unit of Length. It is the basic unit of Length in the Metric system and in the International Kelp forests are underwater areas with a high density of Kelp. Another example is Sargassum, which creates unique habitats in the tropical waters of the Sargasso Sea. Sargassum is a genus of generally planktonic (free-floating macroalgae ( Seaweed) in the order Fucales. The Sargasso Sea is an elongated region in the middle of the North Atlantic Ocean surrounded by Ocean currents. This is one of the few areas where a large biomass of brown algae may be found in tropical waters. The Tropics are centered on the Equator and limited in Latitude by the Tropic of Cancer in the northern hemisphere at approximately 23°26' (23 Many brown algae such as members of the order Fucales are commonly found along rocky seashores. Fucales is an order in the Phylum Phaeophyta or Brown algae. Members of this order are fucoids Some members of the division are used as food for humans.

Worldwide there are about 1500-2000 brown seaweed species. In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. [1]

Brown algae belong to a very large group, the Heterokontophyta, a eukaryotic group of organisms distinguished most prominently by having chloroplasts surrounded by four membranes, suggesting an origin from a symbiotic relationship between a basal eukaryote and another eukaryotic organism. The heterokonts or stramenopiles are a major line of Eukaryotes presently containing about 10500 known species Chloroplasts are Organelles found in Plant cells and eukaryotic Algae that conduct Photosynthesis. Most brown algae contain the pigment fucoxanthin, which is responsible for the distinctive greenish-brown color that gives them their name. Fucoxanthin is a Carotenoid, with formula C42H58O6 It is found as an accessory Pigment in the Chloroplasts of Brown algae are unique among heterokonts in developing into multicellular forms with differentiated tissues, but they reproduce by means of flagellate spores, which closely resemble other heterokont cells. In Developmental biology, cellular differentiation is the process by which a less specialized cell becomes a more specialized Cell type. Tissue is a cellular organizational level intermediate between cells and a complete organism A flagellum ( plural flagella) is a tail-like structure that projects from the Cell body of certain Prokaryotic and Eukaryotic cells and it In Biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions Genetic studies show their closest relatives to be the yellow-green algae. Yellow-green algae or xanthophytes are an important group of Heterokont algae

Phaeophyta first appear in the fossil record in the Mesozoic, possibly as early as the Jurassic. FOSSIL is a standard protocol for allowing serial communication for Telecommunications programs under the DOS Operating system. The Mesozoic Era is one of three geologic eras of the Phanerozoic eon. The Jurassic is a geologic period and system that extends from about Ma (million years ago to  Ma that is from the end of the Triassic to the beginning Their occurrence as fossils is rare due to their generally soft-bodied habit, and scientists continue to debate the identification of some finds. Other algae groups, such as the red algae and green algae have a number of calcareous members, which are more likely to leave evidence in the fossil record than the soft bodies of the brown algae. The red algae (Rhodophyta ˌroʊdəˈfaɪtə roʊˈdɒfɨtə from Greek: ῥόδον (rhodon = rose + φυτόν (phyton = plant thus red plant are The green algae (singular green alga) are the large group of Algae from which the Embryophytes (higher plants emerged Calcareous refers to a Sediment, Sedimentary rock, or Soil type which is formed from or contains a high proportion of Calcium carbonate in the FOSSIL is a standard protocol for allowing serial communication for Telecommunications programs under the DOS Operating system. Miocene fossils of a soft-bodied brown macro algae, Julescrania, have been found well-preserved in Monterey Formation diatomites, but few other certain fossils, particularly of older specimens are known in the fossil record. The Miocene is a geological epoch of the Neogene period and extends from about 23 The Monterey Formation is an extensive Miocene Oil -rich geological Sedimentary formation in California with massive outcroppings of the formation Diatomaceous earth (ˌdaɪətəˈmeɪʃəs ˈɝθ also known as DE, TSS, diatomite, diahydro, kieselguhr, kieselgur and [2][1]

Contents

Taxonomy

This is a list of the orders in the class Phaeophyceae:[3]

A few species, such as Botrydium stoloniferum, are placed incertae sedis, or of uncertain position, as to order in this classification scheme. Incertae sedis ( Latin for "of uncertain placement" abbreviated "inc

Life cycle

The life cycle shows great variability from one group to another. However the life cycle of Laminaria consists of the diploid generation, that is the large plant well know to most people. Laminaria is a Genus of 31 Species of Brown algae ( Phaeophyceae) all sharing the common name " Kelp " "Haplo" redirects here For the fictional character see The Death Gate Cycle. It produces sporangia from specialised microscioic structures, these divide meiotically (meiosis) before they are released. In Biology or life science meiosis (pronounced my-oh-sis is a process of reductional division in which the number of chromosomes per cell is cut in half As they are haploid there are equal numbers of male and female spores. "Haplo" redirects here For the fictional character see The Death Gate Cycle. [1] With the exception of the Fucales all brown algae have a life cycle which consists of an alternation between morphologically haploid and diploid plants referred to as Monomorphic. A dimorphic life cycle consists of an alteration between dissimilar haploid and diploid plants. [4]

Adaptations

Brown algae have adapted to a wide variety of marine ecological niches including the tidal splash zone, rock pools, the whole intertidal zone and relatively deep near shore waters. However they are predominantly cool and cold water organisms that benefit from nutrients in up welling cold water currents and inflows from land; Sargassum being an obvious exception to this generalisation.

References

  1. ^ a b Thomas,D. N. 2002. Seaweeds. The Natural History Museum, London. ISBN 0 56509175 1
  2. ^ Coyer, J. A. ; G. J. Smith, R. A. Anderson (2001). "Evolution of Macrocystis spp. (Phaeophyta) as determined by ITS1 and ITS2 sequences". Journal of Phycology 37: 574-585. Blackwell Publishing.  
  3. ^ Guiry, M. D. & G. M. Guiry (2006). AlgaeBase version 4.2. National University of Ireland, Galway. The National University of Ireland ( NUI) (Ollscoil na hÉireann is a federal University system of constituent universities, previously called Retrieved on 7 December 2006. Events 43 BC - Marcus Tullius Cicero assassinated 1696 - Connecticut Route 108, one of the oldest highways Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar.
  4. ^ Fletcher,R. L. 1987. Seaweeds of the British Isles. Volume 3. Part 1. British Museum (Natural History), London. ISBN 0 565 00992 3

Further reading

Druehl, L. D. 1988. Cultivated edible kelp. in Algae and Human Affairs. Lembi, C. A. and Waaland, J. R. (Editors) 1988. ISBN 0 521 32115 8.

See also

External links

Cyanobacteria, also known as blue-green algae, blue-green bacteria or Cyanophyta, is a phylum of Bacteria that obtain their energy Diatoms ( Greek: (dia = "through" + (temnein = "to cut" i Fucus is a Genus of Brown alga ( Seaweed) in the Class Phaeophyceae to be found in the intertidal zones of rocky shores The golden algae or chrysophytes are a large group of Heterokont Algae found mostly in freshwater The green algae (singular green alga) are the large group of Algae from which the Embryophytes (higher plants emerged Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales Ascophyllum nodosum is a large common Brown alga, in the Class Phaeophyceae. Laminaria is a Genus of 31 Species of Brown algae ( Phaeophyceae) all sharing the common name " Kelp " The red algae (Rhodophyta ˌroʊdəˈfaɪtə roʊˈdɒfɨtə from Greek: ῥόδον (rhodon = rose + φυτόν (phyton = plant thus red plant are Sargassum is a genus of generally planktonic (free-floating macroalgae ( Seaweed) in the order Fucales. Yellow-green algae or xanthophytes are an important group of Heterokont algae This is a list of the orders, families and genera in the class Phaeophyceae — the Brown algae. Wrack is the common name for several species of Seaweed in the family Fucaceae. Turbinaria ornata is a tropical brown algae of the order Fucales native to Coral reef ecosystems of the South Pacific. The National University of Ireland Galway ( NUI Galway) ( Irish Ollscoil na hÉireann Gaillimh or OÉ Gaillimh) is a tertiary-level
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