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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] |
Eugenius Warming
Eugenius (died 6 September 394) was a usurper in the Western Roman Empire (392–394) against Emperor Theodosius I. While Christian himself, Eugenius capitalized on the discontent in the West caused by Theodosius' religious policies targeting pagans. He renovated the pagan Temple of Venus and Roma and restored the Altar of Victory, after continued petitions from the Roman Senate. Eugenius replaced Theodosius' administrators with men loyal to him, including pagans. This revived the pagan cause. His army fought the army of Theodosius at the Battle of the Frigidus, where Eugenius was captured and executed. Life A Christian and former teacher of grammar and rhetoric, as well as ''magister scriniorum'', Eugenius was an acquaintance of Arbogast, the ''magister militum''. Arbogast was of Frankish origin and ''de facto'' ruler of the western portion of the Empire. Rise to power Following the death of Valentinian II, Eugenius was elevated to ''augustus'' on 22 August 392 at Lyons, by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagella
A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have from one to many flagella. A gram-negative bacterium ''Helicobacter pylori'' for example uses its multiple flagella to propel itself through the mucus lining to reach the stomach epithelium, where it may cause a gastric ulcer to develop. In some bacteria the flagellum can also function as a sensory organelle, being sensitive to wetness outside the cell. Across the three domains of Bacteria, Archaea, and Eukaryota the flagellum has a different structure, protein composition, and mechanism of propulsion but shares the same function of providing motility. The Latin word means " whip" to describe its lash-like swimming motion. The flagellum in archaea is called the archaellum to note its difference from the bacterial flagellum. Eukaryoti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dunaliellaceae
Dunaliellaceae is a family of algae in the order Chlamydomonadales.See the NCBIbr>webpage on Dunaliellaceae Data extracted from the Genera As accepted by GBIF; * '' Aulacomonas'' (1) * ''Dunaliella'' (5) * '' Hafniomonas'' (2) * '' Phyllocardium'' (1) * ''Polytomella ''Polytomella'' is a genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and b ...'' (3) * '' Quadrichloris'' (1) * '' Spermatozopsis'' (1) Figures in brackets are approx. how many species per genus. Uncertain genera, (with no listed species); ''Apiochloris'' , ''Chloronephris'' , ''Hyaliella'' , ''Hyalocardium'' , ''Medusochloris'' , ''Papenfussiomonas'' , ''Platella'' , ''Silvamonas'' and ''Ulochloris'' References Chlorophyceae families Chlamydomonadales {{Chlorophyceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dunaliella
''Dunaliella'' is a single-celled, photosynthetic green alga, that is characteristic for its ability to outcompete other organisms and thrive in hypersaline environments. It is mostly a marine organism, though there are a few freshwater species that tend to be more rare. It is a genus in which certain species can accumulate relatively large amounts of β-carotenoids and glycerol in very harsh growth conditions consisting of high light intensities, high salt concentrations, and limited oxygen and nitrogen levels, yet is still very abundant in lakes and lagoons all around the world. It becomes very complicated to distinguish and interpret species of this genus on simply a morphological and physiological level due to the organism's lack of cell wall that allows it to have malleability and change shape and its different pigments that allows it to change colours depending on the environmental conditions. Molecular phylogeny analysis has become a critical protocol in discovering the ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oedogoniales
The Oedogoniales are an order of filamentous freshwater green algae of the class Chlorophyceae. The order is well-defined and has several unique features, including asexual reproduction with zoospores that possess stephanokont flagella: numerous short flagella arranged in a subapical whorl. The oedogoniales have a highly specialized type of oogamy, and an elaborate method of cell division which results in the accumulation of apical caps. The order comprises one family, Oedogoniaceae, with three genera. Some common features among these genera may be obscure. The hairs of ''Bulbochaete'' and the heterotrichous system ''Oedocladium'' are similar to Chaetophorales, with which they may share a distant relationship. Of the genus Oedogonium' there are over 330 species, about 70 species of ''Bulbochaete'', and 10 species of ''Oedocladium''. More than half of these species are known to North America.Tiffany, L. H. (1955). ''Geographic Distribution of the North American Species of the Oe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaetophorales
Chaetophorales is an order of green algae in the class Chlorophyceae 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, p .... Families * '' Aphanochaetaceae'' Oltmanns * '' Barrancaceae'' Caisová et al. * '' Chaetophoraceae'' Greville * '' Fritschiellaceae'' Caisová & Melkonian * '' Schizomeridaceae'' G.M.Smith * '' Uronemataceae'' Caisová et al. References Chlorophyta orders {{Chlorophyceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaetopeltidales
Chaetopeltidales are an order of green algae in the class Chlorophyceae 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, p .... References External links Chlorophyta orders {{Chlorophyceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AlgaeBase
AlgaeBase is a global species database of information on all groups of algae, both marine and freshwater, as well as sea-grass. History AlgaeBase began in March 1996, founded by Michael Guiry. Text was copied from this source, which is available under Attribution 4.0 International (CC BY 4.0)licence. (Sehere. By 2005, the database contained about 65,000 names. In 2013, AlgaeBase and the Flanders Marine Institute (VLIZ) signed an end-user license agreement regarding the Electronic Intellectual Property of AlgaeBase. This allows the World Register of Marine Species (WoRMS) to include taxonomic names of algae in WoRMS, thereby allowing WoRMS, as part of the Aphia database, to make its overview of all described marine species more complete. Synchronisation of the AlgaeBase data with Aphia and WoRMS was undertaken manually until March 2015, but this was very time-consuming, so an online application was developed to semi-automate the synchronisation, launching in 2015 in conju ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oogamous
Oogamy is an extreme form of anisogamy where the gametes differ in both size and form. In oogamy the large female gamete (also known as ovum) is immobile, while the small male gamete (also known as sperm) is mobile. Oogamy is a common form of anisogamy, with almost all animals and land plants being oogamous. Occurrence Oogamy is found in most species that reproduce sexually, all higher species being oogamous. Oogamy is found in all land plants, and in some red algae, brown algae and green algae. Oogamy is favored in plants because only one gamete has to travel through harsh environments outside the plant. Oogamy is also present in oomycetes. Almost all animals are oogamous. There are exceptions, such as the opiliones that have immobile sperm. Etymology The term oogamy was first used in the year 1888. Evolution It is generally accepted that isogamy is the ancestral state and that oogamy evolves from isogamy through anisogamy. However, transitions do exist between anisog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anisogamous
Different forms of anisogamy: A) anisogamy of motile cells, B) egg_cell.html"_;"title="oogamy_(egg_cell">oogamy_(egg_cell_and_sperm_cell),_C)_anisogamy_of_non-motile_cells_(egg_cell_and_spermatia)..html" ;"title="egg_cell_and_sperm_cell.html" ;"title="egg_cell.html" ;"title="oogamy (egg cell">oogamy (egg cell and sperm cell">egg_cell.html" ;"title="oogamy (egg cell">oogamy (egg cell and sperm cell), C) anisogamy of non-motile cells (egg cell and spermatia).">283x283px Anisogamy is a form of sexual reproduction that involves the union or fusion of two gametes that differ in size and/or form. The smaller gamete is male, a sperm cell, whereas the larger gamete is female, typically an [ gg cell. Anisogamy is predominant among multicellular organisms. In both plants and animals gamete size difference is the fundamental difference between females and males. Anisogamy most likely evolved from isogamy. Since the biological definition of male and female is based on gamete size, the evol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isogamous
Isogamy is a form of sexual reproduction that involves gametes of the same morphology (indistinguishable in shape and size), found in most unicellular eukaryotes. Because both gametes look alike, they generally cannot be classified as male or female. Instead, organisms undergoing isogamy are said to have different mating types, most commonly noted as "+" and "−" strains. Etymology The literal meaning of isogamy is "equal marriage" which refers to equal contribution of resources by both gametes to a zygote. The term isogamous was first used in the year 1887. Characteristics of isogamous species Isogamous species often have two mating types. Some isogamous species have more than two mating types, but the number is usually lower than ten. In some extremely rare cases a species can have thousands of mating types. In all cases, fertilization occurs when gametes of two different mating types fuse to form a zygote. Evolution It is generally accepted that isogamy is an an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
