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Aphelidium
''Aphelidium'' species are endoparasites of freshwater green algae. ''Aphelidium'' belongs to the phylum Aphelida, and is part of the Opisthosporidia, a sister clade to Fungi.Karpov, S. A., Mamkaeva, M. A., Aleoshin, V. V., Nassonova, E., Lilje, O., Gleason, F. H.. 2014: Morphology, phylogeny, and ecology of the aphelids (Aphelidea, Opisthokonta) and proposal for the new superphylum Opisthosporidia. Front. Microbiol.. https://doi.org/10.3389/fmicb.2014.00112 The cells of ''Aphelidium'' are much smaller than the cells of its green algae host, which is protected by a robust cell wall. ''Aphelidium'' have evolved a remarkable life cycle to defeat host's defenses. The infection process for ''Aphelidium'' is notable for its method of entry. An ''Aphelidium'' cyst attached to a potential host will raise its internal pressure by expanding the posterior vacuole before using the sudden release of this pressure to defeat the host cell wall and jet itself into the host. As parasites of green ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aphelidium Life Cycle
''Aphelidium'' species are endoparasites of freshwater green algae. ''Aphelidium'' belongs to the phylum Aphelida, and is part of the Opisthosporidia, a sister clade to Fungi.Karpov, S. A., Mamkaeva, M. A., Aleoshin, V. V., Nassonova, E., Lilje, O., Gleason, F. H.. 2014: Morphology, phylogeny, and ecology of the aphelids (Aphelidea, Opisthokonta) and proposal for the new superphylum Opisthosporidia. Front. Microbiol.. https://doi.org/10.3389/fmicb.2014.00112 The cells of ''Aphelidium'' are much smaller than the cells of its green algae host, which is protected by a robust cell wall. ''Aphelidium'' have evolved a remarkable life cycle to defeat host's defenses. The infection process for ''Aphelidium'' is notable for its method of entry. An ''Aphelidium'' cyst attached to a potential host will raise its internal pressure by expanding the posterior vacuole before using the sudden release of this pressure to defeat the host cell wall and jet itself into the host. As parasites of green ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aphelida
Aphelida is a phylum of Fungi that appears to be the sister to true fungi. Taxonomy * Phylum Aphelidiomycota Tedersoo 2018 phelida Karpov, Aleoshin & Mikhailov 2014ref> ** Class Aphelidiomycetes Tedersoo 2018 phelidea Gromov 2000*** Order Aphelidiales Tedersoo et al. 2018 Aphelidida">nowiki/>Aphelidida_Gromov_2000_non_Cavalier-Smith_2012.html" ;"title="Aphelidida.html" ;"title="nowiki/>Aphelidida">nowiki/>Aphelidida Gromov 2000 non Cavalier-Smith 2012">Aphelidida.html" ;"title="nowiki/>Aphelidida">nowiki/>Aphelidida Gromov 2000 non Cavalier-Smith 2012**** Family Aphelididae Gromov 2000 [Amoeboaphelidiidae Cavalier-Smith 2012] ***** Genus ''Amoeboaphelidium'' Scherffel 1925 emend. Karpov 2014 *****Genus ''Paraphelidium'' Karpov, Moreira & Lopez-Garcia 2017 *****Genus '' Pseudaphelidium'' Schweikert & Schnepf 1996 ***** Genus ''Aphelidium ''Aphelidium'' species are endoparasites of freshwater green algae. ''Aphelidium'' belongs to the phylum Aphelida, and is part of the Opis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryota
Eukaryotes () are organisms whose Cell (biology), cells have a cell nucleus, nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the Three-domain system, three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard (archaea), Asgard archaea. This implies that there are only Two-domain system, two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass (ecology), biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as Flagellated cell, flagellated phagotrophs. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amoeba
An amoeba (; less commonly spelled ameba or amœba; plural ''am(o)ebas'' or ''am(o)ebae'' ), often called an amoeboid, is a type of Cell (biology), cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudopodia, pseudopods. Amoebae do not form a single Taxonomy (biology), taxonomic group; instead, they are found in every major Lineage (evolution), lineage of eukaryote, eukaryotic organisms. Amoeboid cells occur not only among the protozoa, but also in fungi, algae, and animals. Microbiologists often use the terms "amoeboid" and "amoeba" interchangeably for any organism that exhibits amoeboid movement. In older classification systems, most amoebae were placed in the Class (biology), class or subphylum Sarcodina, a grouping of Unicellular organism, single-celled organisms that possess pseudopods or move by protoplasmic flow. However, molecular phylogenetic studies have shown that Sarcodina is not a monophyletic group whose memb ... [...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] |
Pseudopodia
A pseudopod or pseudopodium (plural: pseudopods or pseudopodia) is a temporary arm-like projection of a eukaryotic cell membrane that is emerged in the direction of movement. Filled with cytoplasm, pseudopodia primarily consist of actin filaments and may also contain microtubules and intermediate filaments. Pseudopods are used for motility and ingestion. They are often found in amoebas. Different types of pseudopodia can be classified by their distinct appearances. Lamellipodia are broad and thin. Filopodia are slender, thread-like, and are supported largely by microfilaments. Lobopodia are bulbous and amoebic. Reticulopodia are complex structures bearing individual pseudopodia which form irregular nets. Axopodia are the phagocytosis type with long, thin pseudopods supported by complex microtubule arrays enveloped with cytoplasm; they respond rapidly to physical contact. Some pseudopodial cells are able to use multiple types of pseudopodia depending on the situation: Most of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagellum
A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have from one to many flagella. A gram-negative bacterium ''Helicobacter pylori'' for example uses its multiple flagella to propel itself through the mucus lining to reach the stomach epithelium, where it may cause a gastric ulcer to develop. In some bacteria the flagellum can also function as a sensory organelle, being sensitive to wetness outside the cell. Across the three domains of Bacteria, Archaea, and Eukaryota the flagellum has a different structure, protein composition, and mechanism of propulsion but shares the same function of providing motility. The Latin word means " whip" to describe its lash-like swimming motion. The flagellum in archaea is called the archaellum to note its difference from the bacterial flagellum. Eukaryotic ... [...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] |
Zoospore
A zoospore is a motile asexual spore that uses a flagellum for locomotion. Also called a swarm spore, these spores are created by some protists, bacteria, and fungi to propagate themselves. Diversity Flagella types Zoospores may possess one or more distinct types of flagella - tinsel or "decorated", and whiplash, in various combinations. *Tinsellated (straminipilous) flagella have lateral filaments known as mastigonemes perpendicular to their main axis, which allow for more surface area, and disturbance of the medium, giving them the property of a rudder, that is, used for steering. *Whiplash flagella are straight, to power the zoospore through its medium. Also, the "default" zoospore only has the propelling, whiplash flagella. Both tinsel and whiplash flagella beat in a sinusoidal wave pattern, but when both are present, the tinsel beats in the opposite direction of the whiplash, to give two axes of control of motility. Morphological types In eukaryotes, the four main types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater Phytoplankton
Freshwater phytoplankton is the phytoplankton occurring in freshwater ecosystems. It can be distinguished between limnoplankton (lake phytoplankton), heleoplankton (phytoplankton in ponds), and potamoplankton (river phytoplankton). They differ in size as the environment around them changes. They are affected negatively by the change in salinity in the water. Ecology Temperature Temperature correlates with various characteristics of phytoplankton community: in a study of American freshwater plankton by Huisman et al, higher temperatures correlates with increased species richness, increased overall biomass, and decreased cell size. This may have serious implications under global warming, as given lower phytoplankton biomass with the same cell density would provide less food to the grazers and higher trophic levels, and smaller size may favour consumers that are able to access them at the expense of those that prefer larger algae. Chlorophyll α Chlorophyll α is the core ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obligate Parasite
An obligate parasite or holoparasite is a parasitic organism that cannot complete its life-cycle without exploiting a suitable host. If an obligate parasite cannot obtain a host it will fail to reproduce. This is opposed to a facultative parasite, which can act as a parasite but does not rely on its host to continue its life-cycle. Obligate parasites have evolved a variety of parasitic strategies to exploit their hosts. Holoparasites and some hemiparasites are obligate. It is advantageous for the parasite to preserve the health of their host when this is compatible with their nutritional and reproductive requirements, except when the death of the host is necessary for transmission.Combes, C. (1997) Fitness of Parasites: Pathology and Selection ''International Journal for Parasitology'' 27 (1): 1–10. Species Obligate parasitism is exhibited in a range of organisms, with examples in viruses, bacteria, fungi, plants, and animals.Balashov, Yu.S. (2011) Parasitism and Ecological Paras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monophyly
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic groups are typically characterised by shared derived characteristics ( synapomorphies), which distinguish organisms in the clade from other organisms. An equivalent term is holophyly. The word "mono-phyly" means "one-tribe" in Greek. Monophyly is contrasted with paraphyly and polyphyly as shown in the second diagram. A ''paraphyletic group'' consists of all of the descendants of a common ancestor minus one or more monophyletic groups. A '' polyphyletic group'' is characterized by convergent features or habits of scientific interest (for example, night-active primates, fruit trees, aquatic insects). The features by which a polyphyletic group is differentiated from others are not inherited from a common ancestor. These definitions have taken ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
