|
Opalozoa
Opalozoa is a subphylum of heterotrophic protists of the phylum Bigyra, and is the sister group to Sagenista. Opalozoans are non-photosynthetic heterokonts that are ancestrally phagotrophic but many times have evolved to be osmotrophic saprotrophs in the gut of vertebrate animals. Taxonomy History: phylum Opalozoa In 1993 the name “Opalozoa” referred to a group of protists that was very different from what it is now. It was a phylum composed of many unrelated zooflagellates, grouped together because of the common presence of tubular mitochondrial cristae and the lack of cortical alveoli or rigid tubular ciliary hairs ( retronemes). It also included the opalinids, proteomyxids and plasmodiophorids. Modern classification The modern taxonomy of Opalozoa, down to order level, is as follows: * Subphylum Opalozoa ** Infraphylum Bikosia *** Class Bikosea ****Subclass Bicosidia *****Superorder Cyathobodoniae ******Order Bicoecida ******Order Anoecida ******Order Pseud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarcomonadia
The sarcomonads () or class Sarcomonadea are a group of amoeboid biciliate protists in the phylum Cercozoa. They are characterized by a propensity to move through gliding on their posterior cilium or through filopodia, a lack of scales or external theca, a soft cell surface without obvious cortical filamentous or membranous skeleton, two cilia without scales or hairs, tubular mitochondrial cristae, near-spherical extrusomes, and a microbody (probably a peroxisome) attached to the nucleus. History In 1993 Cavalier-Smith described the sarcomonads as a subclass known as “Sarcomonadia”, an assemblage of unrelated cercozoans ( thaumatomonads, proteomyxids, cercomonads...) and excavates (jakobids), in the now defunct class “Heteromitea”, in the old phylum “Opalozoa”. This subclass was created to lump together protozoa that have an anisokont type of zoospore (i.e. two cilia of different lengths), are non-thecate and have isodiametric extrusomes. Sarcomonadia was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanomonadea
Nanomonadea is a class of biciliate phagotrophic, non-photosynthetic free-living opalozoans, coontaining the sole order Uniciliatida. This monophyletic group previously known as clade MAST-3 is characterized by a single hairless posterior cilium and absence of an anterior cilium. Phylogeny The cladogram below shows the relationships between Nanomonadea and the rest of Opalozoans. Taxonomy The taxonomy of Nanomonadea is as follows: *Subphylum Opalozoa **Infraphylum Placidozoa ***Superclass Wobblata (paraphyletic) ****Class Nanomonadea *****Order Uniciliatida ******Family Solenicolidae – ''Solenicola ''Solenicola setigera'' is a species of marine stramenopile, and the only species classified within the genus ''Solenicola''. The species ranges between 4–7 µm in diameter and has a complex feeding strategy. Its ecological role within th ...'' ******Family Incisomonadidae – '' Incisomonas'' References {{Taxonbar, from=Q28373662 Placidozoa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bigyra
Bigyra is a grouping of heterokont organisms. It includes Bicosoecida, Blastocystis and Labyrinthulida. It has also been described as containing Opalozoa, Bicoecia, and Sagenista. Phylogeny The cladogram below shows the internal relationships within Bigyra: Classification The modern taxonomy of Bigyra is as follows: *Phylum Bigyra **Subphylum Opalozoa ***Infraphylum Placidozoa ****Superclass Wobblata ( paraphyletic) *****Class Placididea *****Class Nanomonadea *****Class Opalomonadea ****Superclass Opalinata *****Class Opalinea *****Class Blastocystea ''Blastocystis'' is a genus of single-celled heterokont parasites belonging to a group of organisms that are known as the Stramenopiles (also called Heterokonts) that includes algae, diatoms, and water molds. Blastocystis consists of several ... ***Infraphylum Bikosia ****Class Bikosea **Subphylum Sagenista ***Class Labyrinthulea ***Class Eogyrea References External links * * SAR supergroup unranked cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opalinata
Opalinata is a superclass of non-phagotrophic heterokonts that unites the classes Opalinea and Blastocystea, and is the sister group to Opalomonadea. Description When Opalinata was first erected as a taxon in 1926, it was placed as the sole class in the group "Protociliata" and considered as primitive cilliates due to the fact that they move thanks to their numerous cilia and that they both present two nuclei. They were distinguished because they perform syngamy by the complete fusion of uninucleated gametes, while the rest of ciliates, forming "Euciliata" ( Ciliata + Suctoria), perform syngamy through their micronuclei alone while their macronuclei dissolve. The taxon Opalinata was revised in 1996 by Cavalier-Smith and placed in Opalozoa, and is now defined by the following synapomorphies: gut parasitism and the loss of peroxisomes and phagocytosis. Phylogeny The cladogram below shows the relationships between Opalinata and the rest of Opalozoa. Classification The modern t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opalomonadea
Opalomonadea is a class of biciliate phagotrophic opalozoans with an anterior hairy cilium, often from anaerobic habitats. It is a monophyletic group previously known as clade MAST-12, sister to Opalinata Opalinata is a superclass of non- phagotrophic heterokonts that unites the classes Opalinea and Blastocystea, and is the sister group to Opalomonadea. Description When Opalinata was first erected as a taxon in 1926, it was placed as the sole c .... This group was discovered through marine environmental DNA samples; no species have yet been described or cultured. Phylogeny The cladogram below shows the relationships between Opalomonadea and the rest of Opalozoans. References {{reflist Placidozoa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wobblata
Wobblata is a paraphyletic grouping of all placidozoans except Opalinata. It unites the classes Placididea, Nanomonadea and Opalomonadea. Description Members of this group are ancestrally aerobic phagotrophic biciliates. They have tubular mitochondrial cristae and a hairy anterior cilium The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projecti .... They have a split right microtubular root, i.e. one of the two (left and right) microtubular roots that support the feeding groove is split in two. They lack a cytopharynx, and some of them have lost their anterior cilium. Phylogeny The cladogram below shows the relationships between Wobblata and the rest of Opalozoans. References {{reflist Placidozoa Paraphyletic groups ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cortical Alveoli
The cortical alveoli (singular: cortical alveolum) are cellular organelles composed of vesicles located under the cytoplasmic membrane, to which they give support. They have been defined as membrane sacs that strengthen the cellular cortex through the firm fixation to the underlying membrane and microtubules. They typically form a continuous layer that acts as a flexible film, although they can also constitute a semi-rigid structure or the scales of a theca. The cortical alveoli are present in protists of the chromist group Alveolata, whose name references these organelles. Although cortical alveoli are very diverse in shape and function among the different groups of protists, they always share the function of supporting the cytoplasmic membrane. In the case of apicomplexan parasites, they're related to the mobility and facilitate the invasion of host cells, thus they have a considerable importance in medicine. In dinoflagellates the alveoli contain cellulose and compose the scales ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opalinid
The opalines are a small group of peculiar heterokonts, currently assigned to the family Opalinidae, in the order Slopalinida. Their name is derived from the opalescent appearance of these microscopic organisms when illuminated with full sunlight. Most opalines live as endocommensals in the large intestine and cloaca of anurans (frogs and toads), though they are sometimes found in fish, reptiles, molluscs and insects. The unusual features of the opalines, first observed by Antonie van Leeuwenhoek in 1683, has led to much debate regarding their phylogenetic position among the protists. Taxonomy and phylogeny The relationship between opalines and other protists has been a subject of great controversy since the late 19th century, and is not completely resolved at present. Initially, microscopists believed that the thousands of rhythmically beating hair-like structures which cover their surface were cilia, and they placed the opalines in Ciliophora. In the early 20th cen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmotrophic
Osmotrophy is a feeding mechanism involving the movement of dissolved organic compounds by osmosis for nutrition. Organisms that use osmotrophy are called osmotrophs. Some mixotrophic microorganisms use osmotrophy to derive some of their energy. Osmotrophy is used by a diversity of organisms. Organisms that use osmotrophy include bacteria, many species of protists and most fungi. Some macroscopic animals like molluscs, sponges, corals, brachiopods and echinoderms may use osmotrophic feeding as a supplemental food source. Process Osmotrophy as a means of gathering nutrients in microscopic organisms relies on cellular surface area to ensure that proper diffusion of nutrients occur in the cell. In other words, an osmotroph is an organism that has their "stomach" outside of their body. Sometimes, osmotrophs may still have an internal digestive system in addition to still using osmosis as a way to gain supplemental nutrients. Additionally, when organisms increase in size, the su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteomyxid
Proteomyxidea is a class of Cercozoa. Although it is known to be paraphyletic, further research is needed before its classification can be improved. References External links Cercozoa classes {{Cercozoa-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crista
A crista (; plural cristae) is a fold in the inner membrane of a mitochondrion. The name is from the Latin for ''crest'' or ''plume'', and it gives the inner membrane its characteristic wrinkled shape, providing a large amount of surface area for chemical reactions to occur on. This aids aerobic cellular respiration, because the mitochondrion requires oxygen. Cristae are studded with proteins, including ATP synthase and a variety of cytochromes. Background With the discovery of the dual-membrane nature of mitochondria, the pioneers of mitochondrial ultrastructural research proposed different models for the organization of the mitochondrial inner membrane. Three models proposed were: *Baffle model – According to Palade (1953), the mitochondrial inner membrane is convoluted in a baffle-like manner with broad openings towards the intra-cristal space. This model entered most textbooks and was widely believed for a long time. *Septa model – Sjöstrand (1953) suggested that she ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Osmotrophic")
