The glaucophytes, 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. The algae (singular is alga) comprise several different groups of living things that produce energy through photosynthesis. ... The inside of a chloroplast 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 Streptophytina (Subdivision) The green algae are the large group of algae from which the embryophytes (higher plants) emerged. ... Divisions Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering plants Adiantum pedatum (a fern... Red algae Classes Florideophyceae Bangiophyceae Cyanidiophyceae The red algae are a large group of mostly multicellular, marine algae, including many notable seaweeds. ... The endosymbiotic theory concerns the origins of mitochondria and plastids (plastids with chlorophyll a and b are called chloroplasts, some other plastids are called cyanelles and rhodoplasts),which are organelles of eukaryotic cells. ... 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 the pigment phycobilin to capture some wavelengths of light; the green algae and higher plants have lost that pigment. Phycobilins are the chromophores of phycobiliproteins (photosynthetic pigments) found in cyanobacteria and in the chloroplasts of red algae, glaucophytes and some cryptomonads (though not in green algae and higher plants). ...

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. Mitochondria are visible as thread-like structures in the light microscope. ... Light micrograph of a newt lung cell in early anaphase of mitosis. ... A centriole in biology is a barrel shaped microtubule structure found in most animal cells, and cells of fungi and algae though not frequently in plants. ... A flagellum (plural, flagella) is a whip-like organelle that many unicellular organisms, and some multicellular ones, use to move about. ... This article is in need of attention from an expert on the subject. ...

There are three main genera included here. Glaucocystis is non-motile, though it retains very short vestigial flagella, and has a cellulose wall. Cyanophora is motile and lacks a cell wall. Gloeochaete has both motile and non-motile stages, and has a cell wall that does not appear to be composed of cellulose. In biology, a genus (plural genera) is a grouping in the classification of living organisms having one or more related and morphologically similar species. ... A vestigial organ is an organ whose original function has been lost during evolution. ... Cellulose (C6H10O5)n is a long-chain polymer polysaccharide carbohydrate, of beta-glucose. ...