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Geminigera
''Geminigera'' /ˌdʒɛmɪnɪˈdʒɛɹə/ is a genus of cryptophyte from the family Geminigeraceae. Named for its unique 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 Bio ...s, ''Geminigera'' is a genus with a single mixotrophic species. It was discovered in 1968 and is known for living in very cold temperatures such as under the Antarctic ice. While originally considered to be part of the genus ''Cryptomonas'', the genus ''Geminigera'' was officially described in 1991 by D. R. A. Hill. Etymology The genus ''Geminigera'' was named for its unique paired pyrenoids. The name in Latin means "bearer of twins" and was suggested in the original article that declared the genus separate from ''Cryptomonas''. History While the genus ''Geminigera'' was originally described in 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geminigeraceae
Geminigeraceae is a family of cryptophytes containing the five genera ''Geminigera'', ''Guillardia'', ''Hanusia'', ''Proteomonas'' and ''Teleaulax''. They are characterised by chloroplasts containing Cr-phycoerythrin 545, and an inner periplast component (IPC) comprising "a sheet or a sheet and multiple plates if diplomorphic". The nucleomorphs are never in the 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 Bio ..., and there is never a scalariform furrow. The cells do, however, have a long, keeled rhizostyle with lamellae (wings). References Cryptomonads Eukaryote families {{Cryptomonad-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptomonad
The cryptomonads (or cryptophytes) are a group of algae, most of which have plastids. They are common in freshwater, and also occur in marine and brackish habitats. Each cell is around 10–50 μm in size and flattened in shape, with an anterior groove or pocket. At the edge of the pocket there are typically two slightly unequal flagella. Some may exhibit mixotrophy. Characteristics Cryptomonads are distinguished by the presence of characteristic extrusomes called ejectosomes, which consist of two connected spiral ribbons held under tension. If the cells are irritated either by mechanical, chemical or light stress, they discharge, propelling the cell in a zig-zag course away from the disturbance. Large ejectosomes, visible under the light microscope, are associated with the pocket; smaller ones occur underneath the periplast, the cryptophyte-specific cell surrounding. Except for the class ''Goniomonadea'', which lacks plastids entirely, and ''Cryptomonas paramecium'' (previo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptomonad Genera
The cryptomonads (or cryptophytes) are a group of algae, most of which have plastids. They are common in freshwater, and also occur in marine and brackish habitats. Each cell is around 10–50 μm in size and flattened in shape, with an anterior groove or pocket. At the edge of the pocket there are typically two slightly unequal flagella. Some may exhibit mixotrophy. Characteristics Cryptomonads are distinguished by the presence of characteristic extrusomes called ejectosomes, which consist of two connected spiral ribbons held under tension. If the cells are irritated either by mechanical, chemical or light stress, they discharge, propelling the cell in a zig-zag course away from the disturbance. Large ejectosomes, visible under the light microscope, are associated with the pocket; smaller ones occur underneath the periplast, the cryptophyte-specific cell surrounding. Except for the class ''Goniomonadea'', which lacks plastids entirely, and ''Cryptomonas paramecium'' (previo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptomonads
The cryptomonads (or cryptophytes) are a group of algae, most of which have plastids. They are common in freshwater, and also occur in marine and brackish habitats. Each cell is around 10–50 μm in size and flattened in shape, with an anterior groove or pocket. At the edge of the pocket there are typically two slightly unequal flagella. Some may exhibit mixotrophy. Characteristics Cryptomonads are distinguished by the presence of characteristic extrusomes called ejectosomes, which consist of two connected spiral ribbons held under tension. If the cells are irritated either by mechanical, chemical or light stress, they discharge, propelling the cell in a zig-zag course away from the disturbance. Large ejectosomes, visible under the light microscope, are associated with the pocket; smaller ones occur underneath the periplast, the cryptophyte-specific cell surrounding. Except for the class ''Goniomonadea'', which lacks plastids entirely, and ''Cryptomonas paramecium'' (previo ... [...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 env ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
