|
Volvocaceae
The Volvocaceae are a family of unicellular or colonial biflagellates, including the typical genus ''Volvox''. The family was named by Ehrenberg in 1834,From p. 281: ''"VOLVOCINA Nova Familia."'' (Volvocina New Family.) ote: According to p. 145, Ehrenberg's paper was first presented in 1832, revised somewhat, and published in 1834./ref> and is known in older classifications as the Volvocidae. All species are colonial and inhabit freshwater environments. Description The simplest of the Volvocaeans are ordered assemblies of cells, each similar to the related unicellular protist ''Chlamydomonas'' and embedded in a gelatinous matrix. In the genus ''Gonium'', for example, each individual organism is a flat plate consisting of 4 to 16 separate cells, each with two flagella. Similarly, the genera ''Eudorina'' and ''Pandorina'' form hollow spheres, the former consisting of 16 cells, the latter of 32 to 64 cells. In these genera each cell can reproduce a new organism by mitosis.Scot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volvox
''Volvox'' is a polyphyletic genus of chlorophyte green algae in the family Volvocaceae. It forms spherical colonies of up to 50,000 cells. They live in a variety of freshwater habitats, and were first reported by Antonie van Leeuwenhoek in 1700. ''Volvox'' diverged from unicellular ancestors approximately . Description ''Volvox'' is a polyphyletic genus in the volvocine green algae clade. Each mature ''Volvox'' colony is composed of up to thousands of cells from two differentiated cell types: numerous flagellate somatic cells and a smaller number of germ cells lacking in soma that are embedded in the surface of a hollow sphere or coenobium containing an extracellular matrix made of glycoproteins. Adult somatic cells comprise a single layer with the flagella facing outward. The cells swim in a coordinated fashion, with distinct anterior and posterior poles. The cells have anterior eyespots that enable the colony to swim toward light. The cells of colonies in the more basa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yamagishiella
''Yamagishiella'' is a genus of colonial green algae in the family Volvocaceae. ''Yamagishiella'' differs from ''Eudorina'' by its isogamous sexual reproduction, but the vegetative morphology and 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 fu ... characteristics of these two genera (especially ''Y. unicocca'' and ''E. unicocca'') are indistinguishable.Nozaki, H. Flagellated Green Algae: Volvocaceae, ''Yamagishiella''. ''In'': Freshwater algae of North America: ecology and classification. John D. Wehr, Robert G. Sheath, eds. p 242. References External links Yamagishiella- Description with pictures Chlamydomonadales genera Chlamydomonadales {{Chlorophyceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eudorina
''Eudorina'' is a paraphyletic genus in the volvocine green algae clade. Eudorina colonies consist of 16, 32 or 64 individual cells grouped together. Each individual cell contains flagella which allow the colony to move as a whole when the individual cells beat their flagella together. Description by GM Smith (1920, p 95):Smith, GM. Phytoplankton of Inland Lakes of Wisconsin, Part I, Wisconsin Geological and Natural History Survey, Madison, WI. (1920). Description ''Eudorina'' colonies typically consist of 16, 32 or 64 cells, each of which is similar to ''Chlamydomonas reinhardtii ''Chlamydomonas reinhardtii'' is a single-cell green alga about 10 micrometres in diameter that swims with two flagella. It has a cell wall made of hydroxyproline-rich glycoproteins, a large cup-shaped chloroplast, a large pyrenoid, and an eye ...''. These cells are bedded within an extracellular matrix composed of glycoproteins. Colonies are spherical and motile, with motility derived from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platymonas
''Platymonas'' is a genus of green algae in the family Volvocaceae The Volvocaceae are a family of unicellular or colonial biflagellates, including the typical genus ''Volvox''. The family was named by Ehrenberg in 1834,From p. 281: ''"VOLVOCINA Nova Familia."'' (Volvocina New Family.) ote: According to p. 1 .... References External links Chlamydomonadales genera Chlamydomonadales {{green algae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volvulina
''Volvulina'' is a genus of colonial green algae in the family Volvocaceae The Volvocaceae are a family of unicellular or colonial biflagellates, including the typical genus ''Volvox''. The family was named by Ehrenberg in 1834,From p. 281: ''"VOLVOCINA Nova Familia."'' (Volvocina New Family.) ote: According to p. 1 .... The colony (coenobium) is broadly ellipsoidal or spherical and consists of a fixed number of cells, usually 16 in mature individuals (rarely 4, 8 or 32). The cells are located at periphery of the coenobium and separated from each other by being embedded in a swollen sack. The cell body is lens-shaped or half spherical when mature with two flagella. The chloroplast is dish- or bowl-shaped. Pyrenoids may be present or absent, the stigma large. The nucleus is centrally located and there may be 4 to 8 contractile vacuoles. Sexual reproduction is by isogamy. References External links - Description with pictures Chlamydomonadales genera Chlamydomonadal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleodorina
''Pleodorina'' is a genus of colonial green algae in the family Volvocaceae. Description by Gilbert M. Smith (1920, pp 96–97).Smith, GM. Phytoplankton of Inland Lakes of Wisconsin, Part I, Wisconsin Geological and Natural History Survey, Madison, WI. (1920). ''Pleodorina'' Shaw 1894: Colonies always motile; spherical to sub-spherical, with 32-128 cells lying some distance from one another just within the periphery of the homogeneous, hyaline, gelatinous, colonial envelope and not connected by cytoplasmic strands. Cells differentiated into those that are purely vegetative in character and those capable of dividing to form daughter colonies. All but four cells of the colony reproductive or about half reproductive and half vegetative. Cells spherical to ovoid in shape. Vegetative cells with a cup-shaped chloroplast containing one pyrenoid; a large anterior eyespot; two cilia of equal length with two contractile vacuoles at their base. Reproductive cells at first like the vegetativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platydorina
''Platydorina'' is a genus of green algae in the family Volvocaceae.See the NCBI The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The ...br>webpage on Platydorina Data extracted from the References External links Chlamydomonadales Chlamydomonadales genera {{Chlorophyceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleodorina Californica
''Pleodorina'' is a genus of colonial green algae in the family Volvocaceae. Description by Gilbert M. Smith (1920, pp 96–97).Smith, GM. Phytoplankton of Inland Lakes of Wisconsin, Part I, Wisconsin Geological and Natural History Survey, Madison, WI. (1920). ''Pleodorina'' Shaw 1894: Colonies always motile; spherical to sub-spherical, with 32-128 cells lying some distance from one another just within the periphery of the homogeneous, hyaline, gelatinous, colonial envelope and not connected by cytoplasmic strands. Cells differentiated into those that are purely vegetative in character and those capable of dividing to form daughter colonies. All but four cells of the colony reproductive or about half reproductive and half vegetative. Cells spherical to ovoid in shape. Vegetative cells with a cup-shaped chloroplast containing one pyrenoid; a large anterior eyespot; two cilia of equal length with two contractile vacuoles at their base. Reproductive cells at first like the vegetativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemiflagellochloris
''Hemiflagellochloris'' is a monotypic genus of green algae in the family Volvocaceae The Volvocaceae are a family of unicellular or colonial biflagellates, including the typical genus ''Volvox''. The family was named by Ehrenberg in 1834,From p. 281: ''"VOLVOCINA Nova Familia."'' (Volvocina New Family.) ote: According to p. 1 .... It has only one known species, ''Hemiflagellochloris kazakhstanica''. References External links Chlamydomonadales genera Chlamydomonadales Monotypic algae genera {{Chlorophyceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatic Cell
A somatic cell (from Ancient Greek σῶμα ''sôma'', meaning "body"), or vegetal cell, is any biological cell forming the body of a multicellular organism other than a gamete, germ cell, gametocyte or undifferentiated stem cell. Such cells compose the body of an organism and divide through the process of binary fission and mitotic division. In contrast, gametes are cells that fuse during sexual reproduction, germ cells are cells that give rise to gametes, and stem cells are cells that can divide through mitosis and differentiate into diverse specialized cell types. For example, in mammals, somatic cells make up all the internal organs, skin, bones, blood and connective tissue, while mammalian germ cells give rise to spermatozoa and ova which fuse during fertilization to produce a cell called a zygote, which divides and differentiates into the cells of an embryo. There are approximately 220 types of somatic cell in the human body. Theoretically, these cells are not germ cells (t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volvox Carteri
''Volvox carteri'' is a species of colonial green algae in the order Volvocales. The ''V. carteri'' life cycle includes a sexual phase and an asexual phase. ''V. carteri'' forms small spherical colonies, or coenobia, of 2000–6000 ''Chlamydomonas-''type somatic cells and 12–16 large, potentially immortal reproductive cells called gonidia. While vegetative, male and female colonies are indistinguishable; however, in the sexual phase, females produce 35-45 eggs and males produce up to 50 sperm packets with 64 or 128 sperm each. The genome of this species of algae was sequenced in 2010. ''Volvox carteri'' is a significant model organism for research into the evolution of multicellularity and organismal complexity, largely due to its simple differentiation into two cell types, versatility in controlled laboratory environments, and natural abundance. Differentiation ''Volvox carteri'' is a useful model organism for understanding the evolution and developmental genetics of cellula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
