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Tetrastrum Heteracanthum
''Tetrastrum'' is a genus of green algae (Chlorophyta). It is a common component of the phytoplankton of freshwater habitats, particularly eutrophic and alkaline waters. Although traditionally classified in the family Scenedesmaceae in the class Chlorophyceae, it is phylogenetically more closely related to the genus '' Oocystis'' of the family Oocystaceae (Trebouxiophyceae). History The genus ''Tetrastrum'' has a tangled taxonomic history. The name was first coined in 1895 by Robert Chodat for the species '' Tetrastrum heteracanthum'', which was previously placed in the now-obsolete genus ''Staurogenia''. Later, the genus ''Cohniella'' was created by Ludwig Julius Bruno Schröder, containing the species ''Cohniella staurogeniiforme''. Later, Ernst Lemmermann merged the genus ''Cohniella'' into ''Tetrastrum''. Description ''Tetrastrum'' consists of four-celled colonies, which are sometimes aggregated together to form compound colonies. A layer of mucilage surrounding the col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scenedesmaceae
Scenedesmaceae is a family of green algae in the order Sphaeropleales. ''Scenedesmus'' algae are commonly found in freshwater plankton. The former family Coelastraceae is considered a synonym of Scenedesmaceae. Genera Genera in this family include: * '' Acutodesmus'' * '' Asterarcys'' * '' Astrocladium'' * '' Chodatodesmus'' * '' Closteriococcus'' * ''Coelastrella'' * '' Coelastropsis'' * '' Coelastrum'' * '' Comasiella'' * '' Crucigeniopsis'' * ''Danubia'' * ''Desmodesmus'' * ''Dimorphococcus'' * ''Enallax'' * '' Flechtneria'' * ''Gilbertsmithia'' * '' Hariotina'' * '' Hofmania'' * '' Hylodesmus'' * '' Komarekia'' * '' Lauterborniella'' * '' Neodesmus'' * '' Pectinodesmus'' * '' Pseudodidymocystis'' * '' Pseudotetrastrum'' * '' Scenedesmus'' * '' Schistochilium'' * '' Schmidledesmus'' * '' Schroederiella'' * '' Scotiellopsis'' * '' Soropediastrum'' * '' Staurogenia'' * '' Steinedesmus'' * ''Tetradesmus'' * '' Tetrallantos'' * '' Tetranephris'' * '' Tetrastrum'' * '' Trunca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asexual Reproduction
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent and thus the newly created individual is genetically and physically similar to the parent or an exact clone of the parent. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea and bacteria. Many eukaryotic organisms including plants, animals, and fungi can also reproduce asexually. In vertebrates, the most common form of asexual reproduction is parthenogenesis, which is typically used as an alternative to sexual reproduction in times when reproductive opportunities are limited. Komodo dragons and some monitor lizards can also reproduce asexually. While all prokaryotes reproduce without the formation and fusion of gametes, mechanisms for lateral g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Microscopy
Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of microscopy: optical, electron, and scanning probe microscopy, along with the emerging field of X-ray microscopy. Optical microscopy and electron microscopy involve the diffraction, reflection, or refraction of electromagnetic radiation/electron beams interacting with the specimen, and the collection of the scattered radiation or another signal in order to create an image. This process may be carried out by wide-field irradiation of the sample (for example standard light microscopy and transmission electron microscopy) or by scanning a fine beam over the sample (for example confocal laser scanning microscopy and scanning electron microscopy). Scanning probe microscopy involves the interaction of a scanning probe with the surface of the ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrenoid
Pyrenoids are sub-cellular 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 photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). Pyrenoids therefore seem to have a role analogous to that of carboxysomes in cyanobacteria. Algae are restricted to aqueous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroplast
A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in the energy-storage molecules ATP and NADPH while freeing oxygen from water in the cells. The ATP and NADPH is then used to make organic molecules from carbon dioxide in a process known as 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 unicellular algae, up to 100 in plants like '' Arabidopsis'' and wheat. A chloroplast is characterized by its two membranes and a high concentration of chlorophyll. Other plastid types, such as the leucoplast and the chromoplast, contain little chlorophyll and do not carry out photosynthesis. Chloroplasts are highly dynamic—they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Nucleus
The cell nucleus (pl. nuclei; from Latin or , meaning ''kernel'' or ''seed'') is a membrane-bound organelle found in eukaryotic cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoclasts have many. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm; and the nuclear matrix, a network within the nucleus that adds mechanical support. The cell nucleus contains nearly all of the cell's genome. Nuclear DNA is often organized into multiple chromosomes – long stands of DNA dotted with various proteins, such as histones, that protect and organize the DNA. The genes within these chromosomes are structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the cell by regulating g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucilage
Mucilage is a thick, gluey substance produced by nearly all plants and some microorganisms. These microorganisms include protists which use it for their locomotion. The direction of their movement is always opposite to that of the secretion of mucilage. It is a polar glycoprotein and an exopolysaccharide. Mucilage in plants plays a role in the storage of water and food, seed germination, and thickening membranes. Cacti (and other succulents) and flax seeds are especially rich sources of mucilage. Occurrence Exopolysaccharides are the most stabilising factor for microaggregates and are widely distributed in soils. Therefore, exopolysaccharide-producing "soil algae" play a vital role in the ecology of the world's soils. The substance covers the outside of, for example, unicellular or filamentous green algae and cyanobacteria. Amongst the green algae especially, the group Volvocales are known to produce exopolysaccharides at a certain point in their life cycle. It occurs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernst Lemmermann
Ernst Johann Lemmermann (27 May 1867 in Bremen – 11 May 1915 in Bremen) was a German botanist who specialized in the field of phycology. During his career he taught classes (''Seminarlehrer'') in Bremen, where he also worked as a botanical assistant at the '' Städtisches Museum für Natur-, Völker- und Handelskunde''. In Bremen he was an instructor to biologist A biologist is a scientist who conducts research in biology. Biologists are interested in studying life on Earth, whether it is an individual cell, a multicellular organism, or a community of interacting populations. They usually speciali ... Friedrich Hustedt (1886-1968), who named the diatom species of ''Achnanthes lemmermannii'' in honor of his former teacher in 1933. He was also honoured in 1942, in '' Lemmermanniella'', which is a genus of cyanobacteria belonging to the family Synechococcaceae, and '' Lemmermannia'' which is a genus of fresh water trebouxiophyceans, named in 1904.Lemmermann, E. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Chodat
Robert Hippolyte Chodat (4 June 1865, Moutier – 28 April 1934) was a Swiss botanist and phycologist who was a professor and director of the botanical institute at the University of Geneva. He studied medicine and botany at Geneva, where he was later a lecturer of pharmacy. In 1889 he attained the title of associate professor, two years later becoming a full professor of medical and pharmaceutical botany. From 1900 onward, he taught classes in general and systematic botany. In 1908 he was appointed rector at the University of Geneva. Chodat was a leading authority of the botanical family Polygalaceae. In 1914, with Emil Hassler (1864–1937), he collected plants in Región Oriental of Paraguay. He was made Chevalier de la Légion d'Honneur in 1909. He was winner of the 1933 Linnean Medal. Selected publications * ''Monographia Polygalacearum'', vol.1 1891, vol.2 1893. * 1898–1907 : ''Plantae Hasslerianae'' (with Emil Hassler).RAMELLA, L. & P. PERRET (2003b). Editores, autores ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trebouxiophyceae
The Trebouxiophyceae are a class of green algae, in the division Chlorophyta. Their circumscription within the green algae is not well established due to the need for more genetic studies at higher levels within the group. Genera without intervening taxonomy include: * ''Choricystis'' * ''Crucigenia'' * ''Koliellopsis'' * '' Leptosira'' * ''Rhopalosolen'' * ''Viridiella ''Viridiella'' is a genus of green algae in the class Trebouxiophyceae. , AlgaeBase AlgaeBase is a global species database of information on all groups of algae, both marine and freshwater, as well as sea-grass. History AlgaeBase began in ...'' * '' Prototheca'' See also * List of Trebouxiophyceae genera References Green algae classes it is also the very well-known album by WUDU SJON {{green algae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
