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Goniaceae
Goniaceae is a family of algae in the order Chlamydomonadales, that includes the genera ''Astrephomene'' and ''Gonium''. Members of the Goniaceae are distinguished from those of the Volvocaceae by having each cell surrounded by a tripartite boundary of the extracellular matrix, as opposed to the entire colony being surrounded by the tripartite boundary in 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. .... References External links Chlorophyceae families Chlamydomonadales {{Chlorophyceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrephomene
''Astrephomene'' is a genus of green algae in the family Goniaceae, order Chlamydomonadales. The genus was first described in 1937 by Pocock and named by Pockock in 1953 (Stein 1958). Taxonomy It was formerly placed in the monotypic family Astrephomenaceae. Astrephomenaceae is now considered obsolete, and ''Astrephomene'' is now classified within the Goniaceae. Description ''Astrephomene gubernaculifera'' is a colonial, flagellated volvocine green algae. It consists of 16, 32, 64 or 128 cells, 2 to 7 of which are small and oriented such that their flagella form a rudder (Stein 1958). Each cell is surrounded by a gelatinous matrix and contains an eyespot, two flagella and 1-3 contractile vacuoles at the anterior end. ''Astrephomene gubernaculifera'' can reproduce sexually or asexually. During asexual reproduction of Astrephomene, rotation of daughter protoplasts occurs in conjunction with the movement of basal bodies during successive cell divisions, ending with the anterio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlamydomonadales
Chlamydomonadales, also known as Volvocales, are an order of flagellated or pseudociliated green algae, specifically of the Chlorophyceae.See the NCBIbr>webpage on Chlamydomonadales Data extracted from the Chlamydomonadales can form planar or spherical colonies. These vary from ''Gonium'' (four to 32 cells) up to ''Volvox'' (500 cells or more). Each cell has two flagella, and is similar in appearance to ''Chlamydomonas'', with the flagella throughout the colony moving in coordination. Both asexual and sexual reproduction occur. In the former, cells divide until they form new colonies, which are then released. In the smaller forms, typically all cells are involved, but larger forms have anterior vegetative and posterior reproductive cells. Sexual reproduction varies from isogamy (both genders produce flagellated gametes of equal size) to oogamy (one gender produces a much larger, nonmotile gamete). The classification of the Chlamydomonadales varies. Very often they are taken ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Gonium
''Gonium'' is a genus of colonial algae, a member of the order Chlamydomonadales. Typical colonies have 4 to 16 cells, all the same size, arranged in a flat plate, with no anterior-posterior differentiation. In a colony of 16 cells, four are in the center, and the other 12 are on the four sides, three each. A description by G.M. Smith (1920, p. 94):Smith, GM. Phytoplankton of Inland Lakes of Wisconsin, Part I, Wisconsin Geological and Natural History Survey, Madison, WI. (1920). ''Gonium'' Mueller 1773: Colonies of 4-8-16 cells arranged in a flat quadrangular plate and embedded in a common gelatinous matrix or connected by broad gelatinous strands. Cells ovoid to pyriform, with a single cup-shaped chloroplast containing one pyrenoid. Each cell with two cilia of equal length, contractile vacuoles at the base of the cilia, and an eyespot. Four- and eight-celled colonies with the cilia on the same side ; sixteen-celled colonies with the four central cells having their ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular microalgae, such as ''Chlorella,'' ''Prototheca'' and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to in length. Most are aquatic and autotrophic (they generate food internally) and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the ''Charophyta'', a division of green algae which includes, for example, ''Spirogyra'' and stoneworts. No definition of algae is generally accepted. One definition is that algae "have chlorophyll ''a'' as their primary photosynthetic pigment and lack a sterile covering of cells around thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorophyceae Families
The Chlorophyceae are one of the classes of green algae, distinguished mainly on the basis of ultrastructural morphology. They are usually green due to the dominance of pigments chlorophyll a and chlorophyll b. The chloroplast may be discoid, plate-like, reticulate, cup-shaped, spiral or ribbon shaped in different species. Most of the members have one or more storage bodies called pyrenoids located in the chloroplast. Pyrenoids contain protein besides starch. Some green algae may store food in the form of oil droplets. They usually have a cell wall made up of an inner layer of cellulose and outer layer of pectose. General characteristics * the body may be unicellular, colonial, filamentous or multicellular. * They are usually green due to the presence of chlorophyll a, chlorophyll b and beta-carotene. * The chloroplast may be discoid, cup-shaped (e.g. ''Chlamydomonas''), spiral or ribbon shaped * Most chlorophytes have one or more storage bodies called pyrenoids (central prot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
