Blue green algae – plant or protozoa?

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    • #5819
      geonyzl
      Participant

      I have encountered in a book about t the blue-green algae, some books consisdered it as a plant some would say it is a protozoan. What is the actual group of these organism? I’m just totally confused because most of the references that had read didn’t explained it thoroughly. Is there a concrete explaination to that? Eventhough I finished that topic in a class 8 years ago but that topic hunts me. 🙂

    • #55463
      victor
      Participant

      well…see this:

      http://en.wikipedia.org/wiki/Blue-green_algae

      Hope it helps

    • #55467
      baikuza
      Participant

      as i know green algae/chlorophyta
      is placed in eukarya domain at 3 domain system…. clasified in plant…
      but not absolutely plant….
      because in the 8-kingdom system it clasified in plant …
      but in 5-kingdom system it is protista….

      oh, well… it depend from which system you look..
      3 domain?8-kingdom? or 5-kingdom?…

    • #55473
      Poison
      Participant

      YOu can call them "plant". But not a member of "Plantae".

    • #55484
      MrMistery
      Participant

      what? people!!! blue-green algae is an old name for cyanobacteria, which fall under eubacteria!!

    • #55725
      baikuza
      Participant

      dear Mr. Mistery…
      i said in the 5-kingdom system it is classified into protista.
      so and it is green algae….not the blue algae….
      did not i?

    • #55731
      victor
      Participant

      I think we’re discussing blue-green algae which is now termed as cyanobacteria which is classified under the kingdom of bacteria even though the botanical systematics still classify blue-green algae below kingdom plantae.

      Here, check this out..:wink:

      quote International Journal of Systematic and Evolutionary Microbiology:

      The cyanobacteria (Cyanophyta, blue-green algae) are also named under the Botanical Code, and the dual nomenclature system causes considerable confusion. This note calls for a more intense involvement of the International Committee on Systematics of Prokaryotes (ICSP), its Judicial Commission and its Subcommittee on the Taxonomy of Photosynthetic Prokaryotes in the nomenclature of the cyanobacteria under the Bacteriological Code.

      For green algae (chlorophyta), it’s classified under kingdom plantae.

    • #56200
      mkwaje
      Participant

      This is getting confusing… There are three domains of life..

      Eukarya — plants, animals, protozoa, fungi
      Eubacteria — true or typical bacteria
      Archaea — ancient bacteria

      Blue green algae (BGA) (this term is not used anymore) or cyanobacteria are classified under domain eubacteria.

    • #56208
      Dr.Stein
      Participant

      Classification is open, means that we cannot say this is wrong, that is right, this is the best, ignore the rest. We can refer to the one we like (usually people take the latest one) as long as we mention the version and we have a reason why choosing that.

    • #56222
      Plymouth John
      Participant
      quote mkwaje:

      Blue green algae (BGA) or cyanobacteria have a very different morphology and chemistry than the true bacteria; hence they are considered under the Archaea. Also included in this group are the extremophiles (e.g. halophiles and thermophiles) which are sometimes termed as cyanobacteria.

      The cyanobacteria branch within the Bacteria, or Eubacteria. They are autotrophic and phototrophic prokaryotes. They are not members of the Archaea, which constitutes a different lineage from the Bacteria.

    • #56264
      Linn
      Participant

      Last I know is for now classed as true bacteria, because it has prokaryotic cells, But, as Dr Stein brought out classification is open. Reason being that cyanobacteria have chlorophyll and produce oxygen, and have pigments called phycobilins just like plants. They are the only "bacteria 😕 " that fix nitrogen and make oxygen, which is really unique 🙂

      So really cyanobacteria does act like a bacteria-plant of sorts. so as soon as the botany scientists figure it out we will have new class of organism perhaps. 🙂

    • #56276
      geonyzl
      Participant

      So if we are going to connect these phyla. These organisms would link the bacterial world to the plant world. The blue green algae would be the bridge between phyla because these are the organisms that have the characteristics of a bacteria and at the same time with the plant?:)

    • #56286
      Dr.Stein
      Participant

      It is stated somewhere (in other classsification) that blue green alga locates between animal and plant. Some blue green algae which actively move e.g. Euglena will refer to animal, whereas the ones which relatively static e.g. Volvox will refer to plants.

      EDIT: I made a mistake. What I wrote above is about Green Algae, NOT Blue-green Algae. Shame on me 😳 😆 But I let that information exists for references 8)

    • #56298
      geonyzl
      Participant

      Hehehe that all right. We are not perfect we do sometimes commit mistakes. 🙂

    • #56323
      mkwaje
      Participant

      cyanobacteria are not the ONLY bacteria capable of nitrogen fixation. Rhizobium for example fixes nitrogen in symbiosis with plants/legumes, and Azotobacter is a free-living soil bacterium capable also of nitrogen fixation.

    • #56369
      Linn
      Participant
      quote mkwaje:

      cyanobacteria are not the ONLY bacteria capable of nitrogen fixation. Rhizobium for example fixes nitrogen in symbiosis with plants/legumes, and Azotobacter is a free-living soil bacterium capable also of nitrogen fixation.

      True some do, but do they also produce oxygen?
      there is prochlorobacteria, that produce oxygen, but it does not have phycobilin pigments.
      nitrogen fixation is basicaly anaerobic (the opposite), so that itself is unusual, as I stated above, that cynobacteria is capable of both fixing nitrogen and producing oxygen. This is what is unique to it.

      I am just saying there are so many interesting and distinct things about it. 🙂

      http://www.pnas.org/cgi/content/full/103/14/5442

    • #56387
      Plymouth John
      Participant

      No, the cyanobacteria do not branch with or link with higher plants which are eukaryotes. Chloroplasts residing within plant cell cytoplasm are believed to have descended from ancestral cyanobacteria which formed a symbiotic (intracellular) relation with early eukaryotic cells (to enable oxygenic photosynthesis to make use of inorganic carbon in the atmosphere). This is the evolutionary link between plants and cyanobacteria, and relates to the origin of eukaryotic cells. But higher plants themselves are classified by the contents of their nuclear genomes (and the phenotypes encoded therein), and in this regard they branch next to animals in the eukaryote phylogeny, a completely different domain from bacteria in the three domain tree of life. You have broached a very big subject here, and the literature will inform you better than I can. Happy studying.

    • #56731
      geonyzl
      Participant

      Hmm. so they are not related eventhough they have distinct resemblance to each other?

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