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Chrysophyte
The Chrysophyceae, usually called chrysophytes, chrysomonads, golden-brown algae, or golden algae, are a large group of algae, found mostly in freshwater. Golden algae is also commonly used to refer to a single species, '' Prymnesium parvum'', which causes fish kills. The Chrysophyceae should not be confused with the Chrysophyta, which is a more ambiguous taxon. Although "chrysophytes" is the anglicization of "Chrysophyta", it generally refers to the Chrysophyceae. Members Originally they were taken to include all such forms of the diatoms and multicellular brown algae, but since then they have been divided into several different groups (e.g., Haptophyceae, Synurophyceae) based on pigmentation and cell structure. Some heterotrophic flagellates as the bicosoecids and choanoflagellates were sometimes seen as related to golden algae too. They are now usually restricted to a core group of closely related forms, distinguished primarily by the structure of the flagella in motile cells ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ochromonadales
Ochromonadales is an order of single-celled algae belonging to the class Chrysophyceae, also known as golden algae. Initially it contained numerous groups of flagellates that were not closely related. During the late 20th century, advancements in molecular and ultrastructural studies allowed the transfer of many of these groups out of Ochromonadales, and the order was reduced to a single family Ochromonadaceae. They are aquatic single-celled flagellated algae, with two heterokont flagella each, some of which have secondarily lost their chloroplasts and appear colorless. Description Species of this order are flagellates, composed of cells capable of swimming by using two flagella. Though ancestrally photosynthetic, some species have secondarily lost this ability, and appear colourless. These are heterotrophic, and can be phagotrophic. Some are mixotrophic, capable of both photosynthesis and phagotrophy, such as '' Poterioomonas'' and '' Ochromonas''. They can be found in marine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, such as cyanobacteria, ''Chlorella'', and diatoms, to multicellular macroalgae such as kelp or brown algae which may grow up to in length. Most algae are aquatic organisms and lack many of the distinct cell and tissue types, such as stomata, xylem, and phloem that are found in embryophyte, land plants. The largest and most complex marine algae are called seaweeds. In contrast, the most complex freshwater forms are the Charophyta, a Division (taxonomy), division of green algae which includes, for example, ''Spirogyra'' and stoneworts. Algae that are carried passively by water are plankton, specifically phytoplankton. Algae constitute a Polyphyly, polyphyletic group because they do not include a common ancestor, and although Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synurid
The synurids (order Synurales) are a small group of heterokont algae, found mostly in freshwater environments, characterized by cells covered in silica scales. Characteristics They are covered in silicate scales and spines. In ''Synura'', these are formed on the surface of the chloroplasts, two of which are usually present, but sometimes only one divided into two lobes is seen. The cells have two heterokont flagella, inserted parallel to one another at the anterior, whose ultrastructure is a distinguishing characteristic of the group. Both asexual and isogamous sexual reproduction occur. Morphology center, upright=2, Classification Synurales are divided into three families, each with one genus: * Family Mallomonas.html" ;"title="Mallomonadaceae ** ''Mallomonas">Mallomonadaceae ** ''Mallomonas'' * Family Synuraceae ** ''Synura'' * Family Neotessellaceae ** ''Neotessella'' (=''Tessella'' ) History The genus ''Synura'' was proposed in 1834 by the German microscopist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinobryon
''Dinobryon'' is a type of microscopic algae. It is one of the 22 genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ... in the family Dinobryaceae. ''Dinobryon'' are mixotrophs, capable of obtaining energy and carbon through photosynthesis and phagotrophy of bacteria. The genus comprises at least 37 described species. The best-known species are ''D. cylindricum'' and ''D. divergens'', which come to the attention of humans annually due to transient blooms in the photic zone of temperate lakes and ponds. Such blooms may produce volatile organic compounds ( VOCs) that produce odors and affect water quality. ''Dinobryon'' can exist as free-living, solitary cells or in branching colonies. Ecology Though most commonly found in freshwater lakes and ponds, ''Dinobryon'' have also b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagellate
A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and their means of motion. The term presently does not imply any specific relationship or classification of the organisms that possess flagella. However, several derivations of the term "flagellate" (such as " dinoflagellate" and " choanoflagellate") are more formally characterized. Form and behavior Flagella in eukaryotes are supported by microtubules in a characteristic arrangement, with nine fused pairs surrounding two central singlets. These arise from a basal body. In some flagellates, flagella direct food into a cytostome or mouth, where food is ingested. Flagella role in classifying eukaryotes. Among protoctists and microscopic animals, a flagellate is an organism with one or more flagella. Some cells in other animals may be flage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amoeboid
An amoeba (; less commonly spelled ameba or amœba; : amoebas (less commonly, amebas) or amoebae (amebae) ), often called an amoeboid, is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudopods. Amoebae do not form a single taxonomic group; instead, they are found in every major lineage of eukaryotic organisms. Amoeboid cells occur not only among the protozoa, but also in fungi, algae, and animals. Microbiologists often use the terms "amoeboid" and "amoeba" interchangeably for any organism that exhibits amoeboid movement. In older classification systems, most amoebae were placed in the class or subphylum Sarcodina, a grouping of single-celled organisms that possess pseudopods or move by protoplasmic flow. However, molecular phylogenetic studies have shown that Sarcodina is not a monophyletic group whose members share common descent. Consequently, amoeboid organisms are no longer classified together in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diatom
A diatom (Neo-Latin ''diatoma'') is any member of a large group comprising several Genus, genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of Earth's Biomass (ecology), biomass. They generate about 20 to 50 percent of the oxygen produced on the planet each year, take in over 6.7 billion tonnes of silicon each year from the waters in which they live, and constitute nearly half of the organic material found in the oceans. The Protist shell, shells of dead diatoms are a significant component of marine sediment, and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by transatlantic winds from the African Sahara, much of it from the Bodélé Depression, which was once made up of a system of fresh-water lakes. Diatoms are unicellular organisms: they occur either as solitary cells or in Colony (biology), colonies, which can take the shape of ribb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterokont
The stramenopiles, also called heterokonts, are protists distinguished by the presence of stiff tripartite external hairs. In most species, the hairs are attached to flagella, in some they are attached to other areas of the cellular surface, and in some they have been secondarily lost (in which case relatedness to stramenopile ancestors is evident from other shared cytological features or from genetic similarity). Stramenopiles represent one of the three major clades in the SAR supergroup, along with Alveolata and Rhizaria. Stramenopiles are eukaryotes; most are single-celled, but some are multicellular including some large seaweeds, the brown algae. The group includes a variety of algal protists, heterotrophic flagellates, opalines and closely related proteromonad flagellates (all endobionts in other organisms); the actinophryid Heliozoa, and oomycetes. The tripartite hairs characteristic of the group have been lost in some of the included taxa – for example in most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stramenopiles
The stramenopiles, also called heterokonts, are Protist, protists distinguished by the presence of stiff tripartite external hairs. In most species, the hairs are attached to flagella, in some they are attached to other areas of the cellular surface, and in some they have been secondarily lost (in which case relatedness to stramenopile ancestors is evident from other shared cytological features or from genetic similarity). Stramenopiles represent one of the three major clades in the SAR supergroup, SAR Supergroup (biology), supergroup, along with Alveolate, Alveolata and Rhizaria. Stramenopiles are Eukaryote, eukaryotes; most are single-celled, but some are multicellular including some large seaweeds, the brown algae. The group includes a variety of algal protists, heterotrophic flagellates, opalines and closely related proteromonad flagellates (all Endosymbiont, endobionts in other organisms); the actinophryid Heliozoa, and oomycetes. The tripartite hairs characteristic of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engler System
One of the prime systems of plant taxonomy, the Engler system was devised by Adolf Engler (1844–1930), and is featured in two major taxonomic texts he authored or co-authored. His influence is reflected in the use of the terms "Engler School" and "Engler Era". Engler's starting point was that of Eichler who had been the first to use phylogenetic principles, although Engler himself did not think that he was. Engler's works His modified Eichler schema first appeared in 1886 in his ''Guide to Breslau Botanic Garden'' (of which he was the director) and was expanded in his '' Syllabus der Pflanzenfamilien'' in 1892. This reflected the new post- Darwinian perspective. Engler's ''Syllabus'' first appeared in 1892 with the title ''Syllabus der Vorlesungen über specielle und medicinisch-pharmaceutische Botanik''. Many subsequent editions have appeared since, and it was continued after Engler's death in 1930. The most recent edition was the 13th in 2009. The other major work was '' Die ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromista
Chromista is a proposed but polyphyletic obsolete Biology, biological Kingdom (biology), kingdom, refined from the Chromalveolata, consisting of single-celled and multicellular eukaryotic species that share similar features in their Photosynthesis, photosynthetic organelles (plastids). It includes all eukaryotes whose plastids contain chlorophyll c, chlorophyll ''c'' and are surrounded by four membranes. If the ancestor already possessed chloroplasts derived by Endosymbiont, endosymbiosis from red algae, all non-photosynthetic Chromista have secondarily lost the ability to photosynthesise. Its members might have arisen independently as separate evolutionary groups from the last eukaryotic common ancestor. Chromista as a taxon was created by the British biologist Thomas Cavalier-Smith in 1981 to distinguish the stramenopiles, haptophytes, and Cryptomonad, cryptophytes. According to Cavalier-Smith, the kingdom originally consisted mostly of photosynthetic eukaryotes (algae), but he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
