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Ankyra (Phrygia)
''Ankyra'' is a genus of green algae in the family Characiaceae. This genus of algae is closely related to '' Atractomorpha'' and ''Sphaeroplea''. They are found in stagnant waters. ''Ankyra'' consists of single cells that are planktonic or epiphytic. Cells are spindle-shaped or cylindrical with the ends tapering into long spines. At one end, the spine is bifid and/or enlarged into a spatula-like appendage. The cell wall consists of two pieces that are joined together at the middle of the cell. One band-shaped chloroplast lines the inside of the cell membrane, and contains a single pyrenoid. Reproduction occurs via zoospores which are released when the two halves of the cell wall break apart, or through a hole formed in the cell wall. Sexual reproduction has not been observed in ''Ankyra''. However, various aplanospore {{Short pages monitor [Baidu] |
Ankyra Ancora
''Ankyra'' is a genus of green algae in the family Characiaceae. This genus of algae is closely related to ''Atractomorpha (alga), Atractomorpha'' and ''Sphaeroplea''. They are found in stagnant waters. ''Ankyra'' consists of single cells that are planktonic or epiphytic. Cells are spindle-shaped or cylindrical with the ends tapering into long spines. At one end, the spine is bifid and/or enlarged into a spatula-like appendage. The cell wall consists of two pieces that are joined together at the middle of the cell. One band-shaped chloroplast lines the inside of the cell membrane, and contains a single pyrenoid. Reproduction occurs via zoospores which are released when the two halves of the cell wall break apart, or through a hole formed in the cell wall. Sexual reproduction has not been observed in ''Ankyra''. However, various aplanospore-like stages and other resting stages have been observed in ''Ankyra'', and need to be studied further. Species are identified based on the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphaeroplea
''Sphaeroplea'' is a genus of green algae in the family Sphaeropleaceae. It was first circumscribed by the Swedish botanist Carl Adolph Agardh in 1824. Description ''Sphaeroplea'' consists of unbranched filaments of cells, one cell thick. Cells are usually 10–50 μm in diameter, but one variety can reach up to 170 μm in diameter. Cells are cylindrical, several times longer than wide, with a linear series of alternating vacuoles and cytoplasmic zones containing nuclei and chloroplasts. The chloroplasts are band-shaped, and contain several pyrenoids. Nuclei are typically in pairs. Reproduction ''Sphaeroplea'' reproduces asexually and sexually. In asexual reproduction, the filaments break apart, although one species has been observed to produce zoospores that are biflagellate (i.e. with two flagella). Sexual reproduction is typically oogamous, where vegetative cells become reproductive cells without changing their shape. Female gametes are large, spherical and green, and are b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphaeropleales Genera
Sphaeropleales is an order of green algae that used to be called Chlorococcales. The order includes some of the most common freshwater planktonic algae such as '' Scenedesmus'' and '' Pediastrum''. The Sphaeropleales includes vegetatively non-motile unicellular, colonial , or filamentous taxa. They have biflagellate zoospores with flagella that are directly opposed in direction (the DO arrangement): '' Sphaeroplea'', '' Atractomorpha'', '' Neochloris'', '' Hydrodictyon'', and '' Pediastrum''. All of these taxa have basal body core connections. Motile cells generally lack cell walls or have only a very fine layer surrounding the cell membrane. Other common characteristics include a robust vegetative cell wall, cup-shaped chloroplasts with large pyrenoids, and relatively large nuclei. With an increase in the number of taxa for which sequence data are available, there is evidence of an expanded DO clade that includes additional zoosporic ('' Bracteacoccus'', '' Schroederia'') an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aplanospore
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Zoospore
A zoospore is a motile asexual spore that uses a flagellum for locomotion in aqueous or moist environments. Also called a swarm spore, these spores are created by some protists, bacteria, and fungi to propagate themselves. Certain zoospores are infectious and transmittable, such as '' Batrachochytrium dendrobatidis'', a fungal zoospore that causes high rates of mortality in amphibians. Diversity General morphology Zoospores are composed of a microtubular cytoskeleton base which extends from the base of the flagellum. The complexity and structure of this cytoskeleton is variable and is largely dependent on volume and size. One common feature of zoospores is their asymmetrical shape; a result of the ventral grove housing the flagella base. Certain zoospores progress through different phases, the first phase commonly referred to as 'the initial'. Others form cysts that vary tremendously in volume (14-4905 cubic micrometers) and shape, each with distinctive hair structures. Flag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrenoid
Pyrenoids are sub-cellular phase-separated micro-compartments found in chloroplasts of many algae,Giordano, M., Beardall, J., & Raven, J. A. (2005). CO2 concentrating mechanisms in algae: mechanisms, environmental modulation, and evolution. ''Annu. Rev. Plant Biol.'', 56, 99-131. and in a single group of land plants, the hornworts.Villarreal, J. C., & Renner, S. S. (2012) Hornwort pyrenoids, carbon-concentrating structures, evolved and were lost at least five times during the last 100 million years. ''Proceedings of the National Academy of Sciences'',109(46), 1873-1887. Pyrenoids are associated with the operation of a carbon-concentrating mechanism (CCM). Their main function is to act as centres of carbon dioxide (CO2) fixation, by generating and maintaining a CO2-rich environment around the photosynthesis, photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). Pyrenoids therefore seem to have a role analogous to that of carboxysomes in cyanobacteria. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroplast
A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which capture the Radiant energy, energy from sunlight and convert it to chemical energy and release oxygen. The chemical energy created is then used to make sugar and other organic molecules from carbon dioxide in a process called the Calvin cycle. Chloroplasts carry out a number of other functions, including fatty acid synthesis, amino acid synthesis, and the immune response in plants. The number of chloroplasts per cell varies from one, in some unicellular algae, up to 100 in plants like ''Arabidopsis'' and wheat. Chloroplasts are highly dynamic—they circulate and are moved around within cells. Their behavior is strongly influenced by environmental factors like light color and intensity. Chloroplasts cannot be made anew by the plant cell and must ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Wall
A cell wall is a structural layer that surrounds some Cell type, cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, and functions as a selective barrier. Another vital role of the cell wall is to help the cell withstand osmotic pressure and mechanical stress. While absent in many eukaryotes, including animals, cell walls are prevalent in other organisms such as fungi, algae and plants, and are commonly found in most Prokaryote, prokaryotes, with the exception of Mollicutes, mollicute bacteria. The composition of cell walls varies across taxonomic groups, species, cell type, and the cell cycle. In Embryophyte, land plants, the primary cell wall comprises Polysaccharide, polysaccharides like cellulose, hemicelluloses, and pectin. Often, other Polymer, polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae exhibit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epiphytic
An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phorophytes. Epiphytes take part in nutrient cycles and add to both the diversity and biomass of the ecosystem in which they occur, like any other organism. In some cases, a rainforest tree's epiphytes may total "several tonnes" (several long tons). They are an important source of food for many species. Typically, the older parts of a plant will have more epiphytes growing on them. Epiphytes differ from parasites in that they grow on other plants for physical support and do not necessarily affect the host negatively. An organism that grows on another organism that is not a plant may be called an epibiont. Epiphytes are usually found in the temperate zone (e.g., many mosses, liverworts, lichens, and algae) or in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planktonic
Plankton are the diverse collection of organisms that drift in water (or air) but are unable to actively propel themselves against currents (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish, and baleen whales. Marine plankton include bacteria, archaea, algae, protozoa, microscopic fungi, and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in lakes and rivers. Mostly, plankton just drift where currents take them, though some, like jellyfish, swim slowly but not fast enough to generally overcome the influence of currents. Although plankton are usually thought of as inhabiting water, there are also airborne versions that live part of their lives drifting in the atmosphere. These '' aeroplankton'' include plant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atractomorpha (alga)
''Atractomorpha'' is a genus in the Sphaeropleaceae, a family of green algae. The genus name is derived from Greek and means "spindle-shaped" or "arrow-shaped", and refers to the shape of the cells. Description ''Atractomorpha'' consists of solitary cells. Cells are variable in size, but range from 25 μm to 6 mm in length. They are usually spindle-shaped, with two sharply pointed ends, but sometimes may develop three- or four-pointed cells. Cells are initially uninucleate (with one cell nucleus), but as the cell develops it becomes multinucleate; the cytoplasm is separated by large vacuoles into zones each containing chloroplasts and nuclei. Chloroplasts are ring-shaped bands or diffusely net-like. Reproduction in ''Atractomorpha'' occurs asexually or sexually. In asexual reproduction, zoospores develop from vegetative cells, or less commonly aplanospores. Zoospores are relatively large, initially spindle-shaped but becoming pyriform or ovate. They are biflagellate but lose th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ankyra Calcarifera
''Ankyra'' is a genus of green algae in the family Characiaceae. This genus of algae is closely related to '' Atractomorpha'' and ''Sphaeroplea''. They are found in stagnant waters. ''Ankyra'' consists of single cells that are planktonic or epiphytic. Cells are spindle-shaped or cylindrical with the ends tapering into long spines. At one end, the spine is bifid and/or enlarged into a spatula-like appendage. The cell wall consists of two pieces that are joined together at the middle of the cell. One band-shaped chloroplast lines the inside of the cell membrane, and contains a single pyrenoid. Reproduction occurs via zoospores which are released when the two halves of the cell wall break apart, or through a hole formed in the cell wall. Sexual reproduction has not been observed in ''Ankyra''. However, various aplanospore {{Short pages monitor [Baidu] |
