are cercozoans photosynthetic

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What are the characteristics of Cercozoa?

The Cercozoa are a group of single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, [5] being defined by molecular phylogenies of rRNA and actin or polyubiquitin. [6] They are the natural predators of many species of microbacteria and Archea .

Are Cercozoa heterotrophic or heterotrophs?

Cercozoa are mostly heterotrophic protozoa dwelling abundantly in soil (where they are the most numerous eukaryotes) and in all freshwater and marine habitats. Some parasitize plants, invertebrate animals and other protists. A few have become algae by enslaving photosynthetic prey to form permanent cellular chimaeras.

What phylum is Cercozoa in?

Cercozoa (Cercozoans) is a phylum of rhizarians. There are 330 species of Cercozoans, in 144 genera and 39 families. This phylum has been around since the paleogene period. It includes groups like Granofilosea, Chlorarachniophyceae, and Thecofilosea.

What is the difference between Cercozoa and bicosoecids?

Bicosoecids are heterokonts—possessing two different types of flagella—and often are attached by one of the flagella to a lorica or to the substrate. Cercozoans have two flagella but are amoeba-flagellates that use pseudopodia for feeding. Some species traditionally considered as amoeba also are now classified as Cercozoa (see below).

Are Cercozoans heterotrophic?

In a recent study conducted in the coastal dunes of the Baltic Sea, using a primer-independent method, Khanipour Roshan et al. [20] showed that Cercozoa were one of the dominant heterotrophic protist groups in young algal and cyanobacterial biocrusts.

Are Cercozoans protozoans?

The protozoan phylum Cercozoa embraces numerous ancestrally biciliate zooflagellates, euglyphid and other filose testate amoebae, chlorarachnean algae, phytomyxean plant parasites (e.g. Plasmodiophora, Phagomyxa), the animal-parasitic Ascetosporea, and Gromia.

What is the distinguishing feature of class Cercozoa?

The Cercozoa are a group of single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, being defined by molecular phylogenies of rRNA and actin or polyubiquitin. They are the natural predators of many species of microbacteria and Archea.

What organisms are included in the Amoebozoans?

Amoebozoa includes many of the best-known amoeboid organisms, such as Chaos, Entamoeba, Pelomyxa and the genus Amoeba itself. Species of Amoebozoa may be either shelled (testate) or naked, and cells may possess flagella. Free-living species are common in both salt and freshwater as well as soil, moss and leaf litter.

What are Radiolarians made of?

silicaThe Radiolaria, also called Radiozoa, are protozoa of diameter 0.1–0.2 mm that produce intricate mineral skeletons, typically with a central capsule dividing the cell into the inner and outer portions of endoplasm and ectoplasm. The elaborate mineral skeleton is usually made of silica.

Which of the following are characteristic of foraminifera?

The most obvious characteristic of foraminifera is the presence of a shell or 'test' that largely encloses the cytoplasmic body and is composed of one or more chambers.

Which group includes many protists with Filose Pseudopodia?

The three main groups of Rhizaria are: Cercozoa – various amoebae and flagellates, usually with filose pseudopods and common in soil.

What is unique about protists members of the Amoebozoans group?

The amoebozoans are classified as protists with pseudopodia which are used in locomotion and feeding. Amoebozoans live in marine environments, fresh water, or in soil. In addition to the defining pseudopodia, they also lack a shell and do not have a fixed body.

Are Amoebozoa heterotrophic or autotrophic?

Amoebas are heterotrophic. Amoebas are single-celled organisms that are distinguished by the formation of pseudopodia, or cellular projections used to help with movement and uptake of extracellular substances.

Do Amoebozoa have mitochondria?

Amoebozoa:Acanthamoeba, Balamuthia, Entamoeba, Endolimax, Iodamoeba. These genera of amoeboid protists belong to the Amoebozoa supergroup. Locomotion of amebae is accomplished by the extrusion of pseudopodia (“false feet”). Amebae are phagocytic and contain mitochondria with tubular cristae.

Which of the following organisms belong to the supergroup Amoebozoa?

Which of the following organisms belong to the supergroup amoebozoans? Slime molds, found in the supergroup amoebozoa, were once classified as fungi.

What are the types of protozoans?

AmoebaGiardia duodenalisFlagellateParasitic protozoansEntamoebaEntamoeba histolyticaProtozoa/Lower classifications

What are the structures that allow locomotion in the Amoebozoa?

These genera of amoeboid protists belong to the Amoebozoa supergroup. Locomotion of amebae is accomplished by the extrusion of pseudopodia (“false feet”). Amebae are phagocytic and contain mitochondria with tubular cristae.

Is Amoebozoa an amoeba?

Amoebozoa are a group of morphologically diverse amoebae, which includes slime molds (e.g., Dictyostelium), lobose amoeba (e.g., Amoeba), and anaerobic Archamoeba (e.g., Entamoeba).

Which supergroup contains parasites?

More contentious are the last two supergroups, the excavates and the chromalveolates, both of which contain important parasitic lineages. The chromalveolates include three major protistan groups which all contain members with chloroplasts derived from a red algal endosymbiosis [53]. The first major group, the alveolates, has long been recognised on morphological grounds [54]; it harbours parasites such as Plasmodium, Toxoplasma and Cryptosporidium. These apicomplexans are reliably placed as related to the dinoflagellates (another group with parasitic representatives) and the ciliates [55,56]. In turn, the alveolates are thought to be related to the stramenopiles, another group initially recognised on morphological grounds [57] that includes diatoms, brown algae and the oomycetes. The third major group in the chromalveolates includes the haptophytes, kathablepharids and cryptophytes [51,58]. The support joining alveolates, stramenopiles and the cryptophyte–haptophyte lineage is variable [59]. Recent analyses have placed the Rhizaria as robustly sister to the group of chromists and alveolates ( Fig. 1 C) which even raises the question of whether there should be six supergroups or five [45,51,60].

How do radiolarians glow?

Of the 400–800 radiolarian and 400–500 phaeodarian living species, only around a dozen are known to be bioluminescent. Both radiolarian and phaeodarian bioluminescence is triggered by mechanical stimulation. Investigated radiolarians respond with a glow lasting typically 1–2 s, but glows lasting >3 s have also been detected, such as in the colonial Rhaphidozoum acuferum and in the solitary Thalassicolla nucleata. The light is blue with a relatively short peak wavelength of 440–460 nm, as compared to other bioluminescent members of the marine plankton, such as dinoflagellates, ctenophores, and crustaceans with wavelength maxima of 470–490 nm.

What is the phylum of plasmodiophorids?

Plasmodiophorid Polymyxa graminis Ledingham (phylum Cercozoa, class Plasmodiophorea, order Plasmodiophorida, family Plasmodiophoridae) is a eukaryotic and biotrophic parasite of plant roots that belongs to a poorly studied, discrete, taxonomic unit informally called the “plasmodiophorids”. Currently, two species, P. graminis L., ( Fig. 21.3) and P. betae Keskin ( Fig. 21.4 ), are recognized. Individually, P. betae and P. graminis are hardly distinguishable morphologically, but molecular characterization can separate the two plasmodiophorids. They transmit at least 12 different plant viruses in the genera Benyvirus, Bymovirus, Furovirus, and Pecluvirus ( Mayo and Pringle, 1998 ). Peanut clump virus (PCV) and Indian peanut clump virus (IPCV) are members of the genus Pecluvirus that affect the production of peanut and monocotyledonous crops. P. graminis is nonpathogenic, but it has the ability to acquire and transmit a range of plant viruses, which cause serious diseases in cereal crop species and result in significant yield reductions. It is responsible for the transmission of several very important plant viruses, including BaYMV and SBWMV characterized by yellow to pale green mosaic mottling and streaking of leaves, and stunted plants are often associated with low, wet areas. The viruses are protected from the environment within P. graminis resting spores (cysts) that may remain dormant but viable for decades (probably until a suitable host plant is encountered). The persistent soilborne nature of these diseases makes virus-resistant crop varieties the only practical and environmentally friendly means of control currently. P. graminis has the ability to acquire and transmit a range of soilborne viruses that belong to at least three genera and can cause economically significant diseases in cereal crops. For example, the winter barley disease caused by barley yellow mosaic virus (BaYMV) and/or barley mild mosaic virus (BaMMV) is widespread in Europe, Japan, and China, and yield losses of >50% may occur when susceptible barley cultivars are grown on severely infested soils ( Ketta et al., 2011; Cox et al., 2014 ). The picture below shows P. graminis, which is the vector of several cereal viruses including BaYMV, growing within a barley root cell.

What is the radiolarian bioluminescence reaction?

The radiolarian bioluminescence reaction involves the luciferin coelenterazine in combination with a Ca 2+ -dependent photoprotein or luciferase. Coelenterazine is the most widespread luciferin, also utilized by some crustaceans, coelenterates, squid, brittlestars, and fish. Small crustaceans (copepods) are one original producer of coelenterazine, which is then distributed throughout the food web and obtained by other organisms that have a dietary requirement for the substance. Whether radiolarians are producers or consumers of coelenterazine is not known, but they are unlikely to obtain the substance from copepod prey as these feed on bacteria and other microorganisms.

Why is global distribution important for protists?

Global distribution has been used as an argument for low protist diversity as it should prevent speciation by geographic isolation or allopatry, the speciation mechanism considered most important. However, most groups detected in environmental surveys show a large 18S rDNA sequence variability, thus strongly disagreeing with the view of low protist diversity. The significance of this large intragroup rDNA diversity is presently not understood but can be relevant, since differences as small as 1% in the 18S rDNA might imply millions of years of evolutionary distance. It is also not clear how this large phylogenetic diversity of protists translates into functional diversity in the open sea or how this diversity is generated and maintained. One possibility is to view the seemingly homogeneous pelagic habitat as a continuum of environmental niches. Thus, there is a large genetic diversity of marine protists, which may have a global distribution, but the ecological implications of this large diversity remain to be investigated.

How to detect microbes in water?

Several methods have been used to detect microbes in drinking water, often aided by the amplification of specific genetic markers via polymerase chain reaction (PCR). Such methods have detected bacteria closely related to public health-relevant genera such as Legionella and Mycobacterium in drinking water ( Figure 2 ). While species of the latter genera have been associated with waterborne illness, their detection does not necessarily imply a health risk or a deficiency in water treatment, as most species within these genera are not pathogenic to humans. Nucleic acid-based methods have also detected fastidious organisms in drinking water such as nitrifying bacteria, whose presence may degrade drinking water quality and thus may reflect inadequate water treatment practices.

Who wrote the current opinion in microbiology?

T. Cavalier-Smith, in Current Opinion in Microbiology, 2002

What is the name of the group of single-celled eukaryotes that lack shared morphological?

Ascetosporea. Gromiidea ( Gromia) The Cercozoa are a group of single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, being defined by molecular phylogenies of rRNA and actin or polyubiquitin. They are the natural predators of many species of microbacteria and Archea .

Is Filose amoebae monophyletic?

They were formerly classified with the euglyphids as the Testaceafilosia. This group is not monophyletic, but nearly all studied members fall in or near the Cercozoa, related to similarly shelled flagellates.

Is Gromia a basal cercozoa?

In addition two groups of parasites, the Phytomyxea and Ascetosporea, and the shelled amoeba Gromia may be basal Cercozoa, although some trees place them closer to the Foraminifera. The spongomonads have been included here, but more recently have been considered Amoebozoa.

What is the name of the group of cercozoa?

Cercozoa were only recently recognised as a monophyletic group (Cavalier-Smith 1997) and were named Cercozoa in 1998 (Cavalier-Smith 1998). The name is based on the cercomonads, amoeboflagellates that are abundant in soil and freshwater, which were first discovered by Dujardin (1841) the father of protozoology, who first realised that protozoa were cells. Even earlier Dujardin (1835) had discovered the reticulose testate cercozoan amoeba Gromia. Cercomonad means ‘tailed monad’, because almost all cercomonads have an extensible pseudopodial tail that is typically drawn out along the posterior gliding cilium, sometimes obscuring it. Dujardin coined the name Rhizopoda (root feet) for organisms having filose or reticulose pseudopods. Unfortunately other authors later confusingly expanded that term to include also the unrelated Amoebozoa, which generally have broad lobose, non-root-like pseudopods. Cercozoa are now known to be one of the most diverse, speciose and ecologically important of all protozoan phyla and include the majority (not all) of eukaryotes with filose pseudopods or cilia that glide on surfaces instead of swimming (Cavalier-Smith and Chao 2003). Many lineages are currently known only from environmental DNA sequencing (Bass and Cavalier-Smith 2004; Bass et al. 2009), so cercozoan diversity must be even greater than is now appreciated.

What are the closest relatives of Cercozoa?

The closest relatives of Cercozoa are the Retaria (Foraminifera and Radiozoa; Cavalier-Smith 1999). Radiozoa are all marine unicellular organisms with microtubule-supported axopodia; they comprise the classical polycystine Radiolaria (with silica skeletons), the Acantharea (with strontium sulphate skeletons), which both also possess axopodia, and the curious floating and axopodially swimming Sticholonche which is not mineralized. Radiozoa now excludes the Phaeodarea, which despite their silica skeleton and axopodia, clearly belong in Cercozoa. Phaeodarea appear to be related to the filosan group known as Thecofilosea, which includes filose testate amoebae without silica scales and also the exclusively marine ebriid flagellates, which like the Phaeodarea have a hollow silica endoskeleton, which might therefore have been a common ancestral character for both groups. A hollow silica endoskeleton is unknown in any other eukaryotes. Two groups of Cercozoa (the euglyphid testate amoebae and the amoeboflagellate thaumatomonads) bear silica scales on their cell surface and are relatively closely related, but apparently not sisters. They have been grouped together as the Imbricatea.

What is the supergroup of Retaria and Cercozoa?

Irrespective of the uncertainty over the precise position of Foraminifera, and thus the monophyly of Retaria and Cercozoa, the grouping of Retaria and Cercozoa as the supergroup Rhizaria is extremely robust. This makes it highly probable that the common ancestor of both Cercozoa and Retaria was a marine benthic amoeboflagellate protozoan with reticulose pseudopods. The name Rhizaria was chosen for this supergroup to perpetuate Dujardin’s idea enshrined in his name Rhizopoda, that slender root-like pseudopods were extremely important for the motility, feeding and general life style of a major group of eukaryotes (Cavalier-Smith 2002). Such tenuous root-like pseudopods can ramify around sediment particles and over surfaces to catch bacteria or eukaryotic prey over large areas or volumes with a minimal investment in protoplasm.

What are the phylogenetic patterns of Filosa?

Within Filosa there are similarly interesting phylogenetic patterns and marine-freshwater dichotomies, some major lineages (e.g. chlorarachneans) being exclusively marine, and others exclusively soil/freshwater (e.g. cercomonads and glissomonads, two groups of zooflagellate gliders). The basal branching order of Filosa is poorly resolved, suggesting very rapid radiation of the major lineages. Four early diverging early-diverging lineages are the zooflagellates that glide on both cilia, the chlorarachnean algae, the marine metromonad gliding flagellates (possibly including the metopiids), and the Granofilosea (naked filose amoebae with granular pseudopods). They all appear to have mutually diverged before cercomonads evolved. The other testate filose amoebae (euglyphids, tectofilosids) are phylogenetically interspersed amongst the large cluster of zooflagellates that has long ciliary transitional regions and dense upper plates (Thaumatomonadida, Spongomonadida, Cryomonadida, Glissomonadida, Pansomonadida). There are weak indications that Glissomonadida are sisters to Pansomonadida and that sainouroids (zooflagellates with exceptionally short centrioles and transition regions and vestigial anterior cilia) may be related to one or both of them and that Thaumatomonadida and Spongomonadida may be sisters, but multigene evidence is essential to resolve the branching order within the long-transition region cluster and to confirm that they are a clade that may be sister to cercomonads.

What are the two structures of the ciliary transition region?

The ciliary transition region bears two characteristic structures absent from all other eukaryotes: the proximal hub-lattice and the distal nonagonal fibre (Cavalier-Smith et al. 2008). In most Cercozoa the ciliary transition region (which lies between where the centriolar triplets end and the ciliary centre pair begins) is very short, but in a few groups that constitute a single derived clade (together with related amoebae) it is rather long, and their nonagonal fibre is obscured by a dense upper transitional plate (Spongomonadida, Thaumatomonadida, Cryomonadida, Pansomonadida, Glissomonadida). The anterior cilium is younger, and the posterior cilium the mature one; thus ciliary transformation occurs over two cell cycles as in other bikont eukaryotes. Cilia typically lack scales (except for the Thaumatomastix anterior cilium) or hairs; simple non-tubular hairs are present in some Allas (anterior) and in Aurigamonas (posterior).

What is an extrusome?

Extrusomes (typically simple and rounded; more elongate in thaumatomonads; very long in cryomonads) are widely present in filosan flagellates and in granofilosans, but not in other cercozoan amoebae.

How many species of Rhizarians are there?

There are probably tens of thousands of rhizarian species with a net-like or thread-like body form which is the central lifestyle for the group which collectively constitutes the most abundant and speciose predators on earth in soils at the bottom of the oceans, lakes and rivers and in the plankton. This microscopic world of incredibly diverse thread or net like predators is ignored by textbooks but is ecologically far more important than lions, tigers, Tyrannosaurus, and wolves. Rhizarians have been the dominant predators for at least 550 million years. They appear to be most closely related to the chromalveolates. Recent multigene trees even suggest that they may have been derived from chromalveolate ancestors by the loss of photosynthesis.

Which subgroup of chromalveolates includes some of the most important photosynthetic organisms answer?

Another major subgroup of the chromalveolates. Protist that include some of the most important photosynthetic organisms on the planet as well as several clades of heterotrophs. Flagellum, which has numerous fine, hairlike projections paired with a shorter "smooth" (nonhairy) flagellum

What is a combonation of autotrophs and heterotrophs?

a combonation of autotrophs and heterotrophs; are photosynthetic but need to get other organic compounds such as carbon through other organisms

How many species of amoebozoans are there?

belong to amoebozoans; include free living and parsitic species, infect all classes of vertebrates as well as some invertebrates; we host at least 6 species, cept one-E histolytica

Which organelle lacks functional electron transport chains?

Organelles that have modified mitochondria (mitosomes); lack functional electron transport chains & cannot use oxygen to extract energy from carbohydrates; use aerobic biochemical pathways to get energy. Ex. Giardia Supgroup of Excavata

Is a protist a heterotroph?

they constitute a large and varied group of amoebozoans; unicellular protists are ubiquitous in soil as well as freshwater and marine environments; most are heterotrophs that actively seek and consume bacteria and other protists.

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