The glaucophytes (Glaucophyta Skuja), also referred to as glaucocystophytes or glaucocystids, are a tiny group of freshwater algae. They are distinguished mainly by the presence of cyanelles, primitive chloroplasts which closely resemble cyanobacteria and retain a thin peptidoglycan wall between their two membranes. Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Typical phyla Rhodophyta (red algae) Chromista Heterokontophyta (heterokonts) Haptophyta Cryptophyta (cryptomonads) Alveolates Pyrrhophyta (dinoflagellates) Apicomplexa Ciliophora (ciliates) Excavates Euglenozoa Percolozoa Metamonada Rhizaria Radiolaria Foraminifera Cercozoa Amoebozoa Choanozoa Many others; classification varies The Kingdom Protista or Protoctista is one of the commonly recognized biological kingdoms, including all the eukaryotes except for... A seaweed (Laurencia) up close: the branches are multicellular and only about 1 mm thick. ... Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. ... Orders The taxonomy of the Cyanobacteria is currently under revision. ... Peptidoglycan, also known as murein, is a substance that forms a homogeneous layer lying outside the plasma membrane in bacteria. ...

It is thought that the green algae (from which the higher plants evolved), red algae and glaucophytes acquired their chloroplasts from endosymbiotic cyanobacteria. The other types of algae received their chloroplasts through secondary endosymbiosis, by engulfing one of those types of algae along with their chloroplasts. Divisions Chlorophyta Charophyta The Green algae (singular: Green Alga) are the large group of algae from which the embryophytes (higher plants) emerged. ... Divisions Green algae Chlorophyta Charophyta Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) †Rhyniophyta - rhyniophytes †Zosterophyllophyta - zosterophylls Lycopodiophyta - clubmosses †Trimerophytophyta - trimerophytes Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta... Possible classes Florideophyceae Bangiophyceae Cyanidiophyceae The red algae (Rhodophyta, pronounced /ˈrəʊdə(ʊ)ˌfʌɪtə/, ancient greek: rhodos phytos = red plant) are a large group of mostly multicellular, marine algae, including many notable seaweeds. ... The endosymbiotic theory, now generally accepted by biologists, concerns the origins of mitochondria and plastids (e. ... Orders The taxonomy of the Cyanobacteria is currently under revision. ...

The glaucophytes are of obvious interest to biologists studying the development of chloroplasts: if the hypothesis that primary chloroplasts had a single origin is correct, glaucophytes are closely related to both green plants and red algae, and may be similar to the original alga type from which all of these developed.

The chloroplasts of glaucophytes, like the cyanobacteria and the chloroplasts of red algae, use phycobiliproteins to capture some wavelengths of light; the green algae and higher plants have lost that pigment. Phycobiliproteins are water-soluble proteins present in cyanobacteria and certain algae (rhodophytes, cryptomonads, glaucocystophytes) that capture light energy which is then passed on to chlorophylls during photosynthesis. ...

Glaucophytes have mitochondria with flat cristae, and undergo open mitosis without centrioles. Motile forms have two unequal flagella, which may have fine hairs and are anchored by a multilayered system of microtubules, both of which are similar to forms found in some green algae. Electron micrograph of a mitochondrion showing its mitochondrial matrix and membranes In cell biology, a mitochondrion (plural mitochondria) (from Greek μιτος or mitos, thread + κουδριον or khondrion, granule) is a membrane-enclosed organelle, found in most eukaryotic cells. ... Mitosis divides genetic information during cell division. ... Organelles. ... A flagellum (plural, flagella) is a whip-like organelle that many unicellular organisms, and some multicellular ones, use to move about. ... Microtubules are protein structures found within cells, one of the components of the cytoskeleton. ...

The three main genera included are: In biology, a genus (plural genera) is a taxonomic grouping. ...

• Glaucocystis Itzigsohn is non-motile, though it retains very short vestigial flagella, and has a cellulose wall.
• Cyanophora Korshikov is motile and lacks a cell wall.
• Gloeochaete Lagerheim has both motile and non-motile stages, and has a cell wall that does not appear to be composed of cellulose.