|
Koliellaceae
Koliellaceae is a family of green algae in the order Prasiolales. Koliellaceae was circumscribed by František Hindák in 1996 to include various green algae that reproduce mainly by simple cell division. Cells are solitary or found in small colonies or filaments. Cells are cylindrical to spherical, with or without a layer of mucilage. The cell wall may be smooth or covered with granulations. Cells contain a single, parietal chloroplast with or without a pyrenoid. Reproduction is typically by cell division into two equally sized cells; however, aplanospores or zoospores may be formed occasionally. Sexual reproduction is oogamous. The taxonomy of this family is problematic because molecular phylogenetics have shown the type genus ''Koliella'' is polyphyletic. The type species of ''Koliella'', ''Koliella spiculiformis, K. spiculiformis'', forms a clade that is closely related to ''Chlorella''; meanwhile, most other species of ''Koliella'' and ''Raphidonema'' are part of a clade inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prasiolales
Prasiolales is an order (biology), order of green algae in the Class (biology), class Trebouxiophyceae. Members of this order are ecologically widespread and are found in freshwater, marine, and terrestrial habitats from the Arctic to the Antarctic. Morphological features include a single stellate, axial chloroplast with a central pyrenoid. The ultrastructure of Prasiolales is unique and includes cells with four flagella, with their basal flagellar apparatuses in a counterclockwise orientation. For a long time, its placement was uncertain and debated between Ulvophyceae and Trebouxiophyceae (also known as Pleurastrophyceae). Molecular data, however, have robustly supported its placement in the latter class. Traditionally the order contained a single family, Prasiolaceae. Molecular phylogenetics studies have found that coccoid algae of very simple morphology, such as ''Stichococcus'', also belong to this order. Genera of uncertain placement to family include: *''Edaphochlorella'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudochlorella
''Pseudochlorella'' is a genus of green algae in the family Koliellaceae. Species , AlgaeBase AlgaeBase is a global species database of information on all groups of algae, both seaweed, marine and freshwater algae, freshwater, as well as sea-grass. History AlgaeBase began in March 1996, founded by Michael D. Guiry, Michael Guiry. Text ... accepts three species: * '' Pseudochlorella pringsheimii'' (Shihar & Krauss) Darienko & al. * '' Pseudochlorella pyrenoidosa'' (Zeitler) J.W.G.Lund * '' Pseudochlorella signiensis'' (Friedl & O'Kelly) Darienko & Pröschold References Trebouxiophyceae genera Prasiolales {{green algae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tree. History The theoretical fra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stichococcus
''Stichococcus'' is a genus of green algae in the family Stichococcaceae. It is a very common algal genus found in a variety of habitats, such as tree trunks, soil, snow, freshwater and marine habitats. One species, '' Stichococcus bacillaris'' is economically important as it produces fatty acids useful for biofuels. The name ''Stichococcus'' originates from the Ancient Greek στίχος (''stíkhos'', "row, line") and κόκκος (''kókkos'', "seed" or "berry"). Description ''Stichococcus'' consists of solitary cells or uniseriate filaments of few cells (2 to 4) that readily break apart. The cells are cylindrical, about three times longer than wide, straight or sometimes curved, with rounded ends often containing vacuoles. Cells are uninucleate with one thin, parietal chloroplast with or without a pyrenoid. Pyrenoids if present are located in the middle of the chloroplast but usually difficult to see. Reproduction occurs by vegetative cell division, and by the fragmentation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prasiola
''Prasiola'' is a genus of macroscopic green algae, found in a variety of habitats ranging from terrestrial, freshwater, to marine. The genus has a cosmopolitan distribution, ranging from the Arctic to the Antarctic. Plants belonging to the genus ''Prasiola'' were first described by John Lightfoot in 1777 in his series ''Flora Scotica'', as the name ''Ulva crispa''. In 1838, Giuseppe Giovanni Antonio Meneghini circumscribed the genus. Species of ''Prasiola'' are edible and are often harvested for food, particularly '' Prasiola japonica'', in countries such as Japan and Myanmar. Description ''Prasiola'' forms single-layered blades which may range in shape from fan-shaped, ribbon-shaped, to wedge-shaped and may or may not have a distinct stipe. In some species, plants start as uniseriate, unbranched filaments or thin ribbons. Blades may be attached to a substrate or may be freely floating or lying. Individual cells are quadrangular, and arranged in regular rows, sometimes gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorella
''Chlorella'' is a genus of about thirteen species of single- celled or colonial green algae of the division Chlorophyta. The cells are spherical in shape, about 2 to 10 μm in diameter, and are without flagella. Their chloroplasts contain the green photosynthetic pigments chlorophyll-a and -b. In ideal conditions cells of ''Chlorella'' multiply rapidly, requiring only carbon dioxide, water, sunlight, and a small amount of minerals to reproduce. The name ''Chlorella'' is taken from the Greek χλώρος, ''chlōros/ khlōros'', meaning green, and the Latin diminutive suffix -''ella'', meaning small. German biochemist and cell physiologist Otto Heinrich Warburg, awarded with the Nobel Prize in Physiology or Medicine in 1931 for his research on cell respiration, also studied photosynthesis in ''Chlorella''. In 1961, Melvin Calvin of the University of California received the Nobel Prize in Chemistry for his research on the pathways of carbon dioxide assimilation in plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Koliella Spiculiformis
''Koliella'' is a genus of green algae in the order Prasiolales. Members of this genus are found in freshwater plankton, but some are also found on snow and ice. The genus name of ''Koliella'' is in honour of Erszébet (Elizabet) Kol (1897-1980), who was a Hungarian botanist (Mycology and Algology), who worked at the Hungarian National Museum in Budapest. The genus was circumscribed by František Hindák in Nova Hedwigia vol.6 (issues 1/2) on page 99 in 1963. Description ''Koliella'' consists of straight or curved spindle-shaped or needle-shaped cells. The apices may be rounded, obtuse, acute, or sharply pointed. Cells contain a single parietal chloroplast lining the inside of the cell, which may be straight or spiraled; a pyrenoid may be present or absent. Oil droplets are also present within the cell. ''Koliella'' reproduces vegetatively by cell division; cells usually detach after division, but may occasionally be found in short chains. It is similar to a number of fusiform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphyletic
A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies, which are explained as a result of convergent evolution. The arrangement of the members of a polyphyletic group is called a polyphyly .. [Source for pronunciation.] It is contrasted with monophyly and paraphyly. For example, the biological characteristic of warm-bloodedness evolved separately in the ancestors of mammals and the ancestors of birds; "warm-blooded animals" is therefore a polyphyletic grouping. Other examples of polyphyletic groups are algae, C4 photosynthesis, C4 photosynthetic plants, and Xenarthra#Evolutionary relationships, edentates. Many taxonomists aim to avoid homoplasies in grouping taxa together, with a goal to identify and eliminate groups that are found to be polyphyletic. This is often the stimulus for major re ... [...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] |
Oogamous
Oogamy is a form of anisogamy where the gametes differ in both size and form. In oogamy the large female gamete (also known as ovum) is immotile, while the small male gamete (also known as spermatozoon) is mobile. Oogamy is a common form of anisogamy, with almost all animals and land plants being oogamous. Oogamy is found in most sexually reproducing species, including all vertebrates, land plants, and some algae. The ancestral state of sexual reproduction is believed to be isogamy, with oogamy evolving through anisogamy. Once oogamy evolves, males and females typically differ in various aspects. Internal fertilization may have originated from oogamy, although some studies suggest that oogamy in certain species may have evolved before the transition from external to internal fertilization. In streptophytes, oogamy occurred before the split from green algae. Occurrence Oogamy is found in almost all animal species that reproduce sexually. There are exceptions, such as the opili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
