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Viridiraptoridae
Viridiraptoridae, previously known as clade X, is a clade of heterotrophic protists in the phylum Cercozoa. They're a family of glissomonads, a group containing a vast, mostly undescribed diversity of soil and freshwater organisms. Morphology and behavior Members of Viridiraptoridae are unicellular biflagellates with naked cells, mostly rigid and variously shaped, without any rostrum or bulge. During the life cycle they can present two different states: a large flagellate state for moving, capable of changing into a surface-attached amoeboid state for feeding. The flagellate state exceeds 10 μm, unlike most known glissomonad families. The amoeboid state retains flagella and shows a bridge-like morphology, with several different adhesion sites. Each cell contains a single vesicular nucleus close to flagellar apparatus, and has an apical position in the flagellate state. The nucleolus is spherical, roughly central, occasionally showing lacunae. The Golgi dictyosomes are close to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orciraptor
''Orciraptor'' is a genus of heterotrophic protists, containing the single species ''Orciraptor agilis''. It belongs to the family Viridiraptoridae, in the phylum Cercozoa. Morphology ''Orciraptor'' are unicellular organisms with two flagella: a short anterior and a long posterior. The cell nucleus is spherical, surrounded by several Golgi dictyosomes. They have cortical extrusomes homogenously distributed in the cell's periphery. In particular, ''Orciraptor agilis'' are colourless gliding cells that in ventral view are compact in shape, measuring 8–14 μm in length, and in lateral view are oviform or tear-shaped, measuring 12–20 μm in length. The posterior flagellum measures an average of 44 μm, while the anterior measures an average of 15 μm and is usually 33–35 % the length of the posterior flagellum. Their spherical nucleus averages 5 μm in diameter, while the nucleolus averages 3 μm, the mitochondria measure 1.5 × 0.7 μm, and the Golgi bodies appear 1.5–3 in l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orciraptor Agilis
''Orciraptor'' is a genus of heterotrophic protists, containing the single species ''Orciraptor agilis''. It belongs to the family Viridiraptoridae, in the phylum Cercozoa. Morphology ''Orciraptor'' are unicellular organisms with two flagella: a short anterior and a long posterior. The cell nucleus is spherical, surrounded by several Golgi dictyosomes. They have cortical extrusomes homogenously distributed in the cell's periphery. In particular, ''Orciraptor agilis'' are colourless gliding cells that in ventral view are compact in shape, measuring 8–14 μm in length, and in lateral view are oviform or tear-shaped, measuring 12–20 μm in length. The posterior flagellum measures an average of 44 μm, while the anterior measures an average of 15 μm and is usually 33–35 % the length of the posterior flagellum. Their spherical nucleus averages 5 μm in diameter, while the nucleolus averages 3 μm, the mitochondria measure 1.5 × 0.7 μm, and the Golgi bodies appear 1.5–3 in l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glissomonad
The glissomonads are a group of bacterivorous gliding flagellated protists that compose the order Glissomonadida, in the amoeboflagellate phylum Cercozoa. They comprise a vast, largely undescribed diversity of soil and freshwater organisms. They are the sister group to cercomonads; the two orders form a solid clade of gliding soil-dwelling flagellates called Pediglissa. Morphology External appearance Glissomonads are zooflagellates that aren't strongly amoeboid, and are only covered by a plasma membrane. Their common ancestor is thought to be a biflagellate, with a short anterior flagellum and a long posterior flagellum, that glided on the substrate by moving their posterior flagellum. In gliding descendants, the cell's posterior zone is usually rounded, giving the cell an ovoid shape. Some species may temporarily extend a protoplasmic tail, that unlike most cercomonads doesn't trail along the posterior flagellum. At least two genera, ''Orciraptor'' and ''Viridiraptor'', are capabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cercozoa
Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or polyubiquitin. They were the first major eukaryotic group to be recognized mainly through molecular phylogenies. They are the natural predators of many species of microbacteria and Archea. They are closely related to the phylum Retaria, comprising amoeboids that usually have complex shells, and together form a supergroup called Rhizaria. Characteristics The group includes most amoeboids and flagellates that feed by means of filose pseudopods. These may be restricted to part of the cell surface, but there is never a true cytostome or mouth as found in many other protozoa. They show a variety of forms and have proven difficult to define in terms of structural characteristics, although their unity is strongly supported by phylogenetic studies. Diversity Some cercozoans are grouped ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viridiraptor
''Viridiraptor'' is a genus of heterotrophic protists, containing the single species ''Viridiraptor invadens''. It belongs to the family Viridiraptoridae, in the phylum Cercozoa. Morphology ''Viridiraptor'' are unicellular biflagellated organisms that have two blunt-ended, slightly unequal flagella and a peripheral conical nucleus closer to the cell's apical end, closely surrounded by several Golgi dictyosomes in its most anterior (anatomy) half. There are cortical extrusomes distributed homogenously across the cell periphery. Ecology and behavior Starving ''Viridiraptor'' cells can glide agitatedly while whipping their anterior flagellum, but they also commonly swim across the water column along a helical path. They invade dead or live cells of large-celled freshwater green algae to feed on their protoplast material, and also propagate within the lumen of the devoured cell. They can also extract plastids from small-celled algae. Etymology The name ''Viridiraptor'' (), meaning 'r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Fission
Binary may refer to: Science and technology Mathematics * Binary number, a representation of numbers using only two digits (0 and 1) * Binary function, a function that takes two arguments * Binary operation, a mathematical operation that takes two arguments * Binary relation, a relation involving two elements * Binary-coded decimal, a method for encoding for decimal digits in binary sequences * Finger binary, a system for counting in binary numbers on the fingers of human hands Computing * Binary code, the digital representation of text and data * Bit, or binary digit, the basic unit of information in computers * Binary file, composed of something other than human-readable text ** Executable, a type of binary file that contains machine code for the computer to execute * Binary tree, a computer tree data structure in which each node has at most two children Astronomy * Binary star, a star system with two stars in it * Binary planet, two planetary bodies of comparable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterivorous
A bacterivore is an organism which obtains energy and nutrients primarily or entirely from the consumption of bacteria. The term is most commonly used to describe free-living, heterotrophic, microscopic organisms such as nematodes as well as many species of amoeba and numerous other types of protozoans, but some macroscopic invertebrates are also bacterivores, including sponges, polychaetes, and certain molluscs and arthropods. Many bacterivorous organisms are adapted for generalist predation on any species of bacteria, but not all bacteria are easily digested; the spores of some species, such as ''Clostridium perfringens'', will never be prey because of their cellular attributes. In microbiology Bacterivores can sometimes be a problem in microbiology studies. For instance, when scientists seek to assess microorganisms in samples from the environment (such as freshwater), the samples are often contaminated with microscopic bacterivores, which interfere with the growing of bacteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Algae
The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as sister of the Zygnematophyceae. Since the realization that the Embryophytes emerged within the green algae, some authors are starting to properly include them. The completed clade that includes both green algae and embryophytes is monophyletic and is referred to as the clade Viridiplantae and as the kingdom Plantae. The green algae include unicellular and colonial flagellates, most with two flagella per cell, as well as various colonial, coccoid and filamentous forms, and macroscopic, multicellular seaweeds. There are about 22,000 species of green algae. Many species live most of their lives as single cells, while other species form coenobia (colonies), long filaments, or highly differentiated macroscopic seaweeds. A few other organi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoplast
Protoplast (), is a biological term coined by Hanstein in 1880 to refer to the entire cell, excluding the cell wall. Protoplasts can be generated by stripping the cell wall from plant, bacterial, or fungal cells by mechanical, chemical or enzymatic means. Protoplasts differ from spheroplasts in that their cell wall has been completely removed. Spheroplasts retain part of their cell wall. In the case of Gram-negative bacterial spheroplasts, for example, the peptidoglycan component of the cell wall has been removed but the outer membrane component has not. Enzymes for the preparation of protoplasts Cell walls are made of a variety of polysaccharides. Protoplasts can be made by degrading cell walls with a mixture of the appropriate polysaccharide-degrading enzymes: During and subsequent to digestion of the cell wall, the protoplast becomes very sensitive to osmotic stress. This means cell wall digestion and protoplast storage must be done in an isotonic solution to prevent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoplasm
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The main components of the cytoplasm are cytosol (a gel-like substance), the organelles (the cell's internal sub-structures), and various cytoplasmic inclusions. The cytoplasm is about 80% water and is usually colorless. The submicroscopic ground cell substance or cytoplasmic matrix which remains after exclusion of the cell organelles and particles is groundplasm. It is the hyaloplasm of light microscopy, a highly complex, polyphasic system in which all resolvable cytoplasmic elements are suspended, including the larger organelles such as the ribosomes, mitochondria, the plant plastids, lipid droplets, and vacuoles. Most cellular activities take place within the cytoplasm, such as many metabolic pathways including glycolysis, and proces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Wall
A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism. Cell walls are absent in many eukaryotes, including animals, but are present in some other ones like fungi, algae and plants, and in most prokaryotes (except mollicute bacteria). A major function is to act as pressure vessels, preventing over-expansion of the cell when water enters. The composition of cell walls varies between taxonomic group and species and may depend on cell type and developmental stage. The primary cell wall of land plants is composed of the polysaccharides cellulose, hemicelluloses and pectin. Often, other polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae possess cell walls made of glycoproteins and polysaccharides such as carrageenan and agar that are absent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phagocytosis
Phagocytosis () is the process by which a cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs phagocytosis is called a phagocyte. In a multicellular organism's immune system, phagocytosis is a major mechanism used to remove pathogens and cell debris. The ingested material is then digested in the phagosome. Bacteria, dead tissue cells, and small mineral particles are all examples of objects that may be phagocytized. Some protozoa use phagocytosis as means to obtain nutrients. History Phagocytosis was first noted by Canadian physician William Osler (1876), and later studied and named by Élie Metchnikoff (1880, 1883). In immune system Phagocytosis is one main mechanisms of the innate immune defense. It is one of the first processes responding to infection, and is also one of the initiating branches of an adaptive immune response. Although mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
