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Ulothrix Implexa
''Ulothrix'' is a genus of green algae in the family Ulotrichaceae. It is a common in fresh to marine habitats, particularly colder and temperate waters. It has a cosmopolitan distribution. The genus includes: * '' Ulothrix aequalis'' Guiry, M.D., John, D.M., Rindi, F and McCarthy, T.K. (ed.) 2007. ''New Survey of Clare Island Volume: The Freshwater and Terrestrial Algae''. Royal Irish Academy. . * ''Ulothrix moniliformis'' * '' Ulothrix flacca'' Burrows, E.M. 1991. ''Seaweeds of the British Isles Volume 2: Chlorophyta''. Natural History Museum, London . * '' Ulothrix implexa'' * '' Ulothrix speciosa'' * ''Ulothrix tenerrima'' * ''Ulothrix tenuissima'' * ''Ulothrix zonata'' Description ''Ulothrix'' consists of cells arranged end-to-end to form unbranched, uniseriate filaments. The filament is attached to a substrate via a basal cell, which may be rhizoidal. Cells are cylindrical or barrel-shaped; the apical cell may somewhat rounded at its terminal end. The cell wall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich Traugott Kützing
Friedrich Traugott Kützing (8 December 1807 in Ritteburg – 9 September 1893) was a German pharmacist, botanist and phycologist. Despite his limited background in regard to higher education, Kützing made significant scientific contributions. In 1833, he demonstrated differences between diatoms and desmids, thus separating the two groups into families of their own. Also, independent of Charles Cagniard-Latour (1777–1859) and Theodor Schwann (1810–1882), he was among the first to provide comprehensive answers in regard to yeast and the role it played in fermentation. In 1849, he published ''Species Algarum'', a large work that provided descriptions for 6000 species of algae. He is the taxonomic authority of the genera '' Syringodium'' (family Cymodoceaceae) and ''Phlebothamnion'' (family Ceramiaceae). Early life As a young man, he worked in several pharmacies in Germany, also serving as assistant for a few semesters at the chemical-pharmaceutical institute of Fran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulothrix Tenuissima
''Ulothrix'' is a genus of green algae in the family Ulotrichaceae. It is a common in fresh to marine habitats, particularly colder and temperate waters. It has a cosmopolitan distribution. The genus includes: * '' Ulothrix aequalis'' Guiry, M.D., John, D.M., Rindi, F and McCarthy, T.K. (ed.) 2007. ''New Survey of Clare Island Volume: The Freshwater and Terrestrial Algae''. Royal Irish Academy. . * ''Ulothrix moniliformis'' * '' Ulothrix flacca'' Burrows, E.M. 1991. ''Seaweeds of the British Isles Volume 2: Chlorophyta''. Natural History Museum, London . * '' Ulothrix implexa'' * '' Ulothrix speciosa'' * ''Ulothrix tenerrima'' * '' Ulothrix tenuissima'' * '' Ulothrix zonata'' Description ''Ulothrix'' consists of cells arranged end-to-end to form unbranched, uniseriate filaments. The filament is attached to a substrate via a basal cell, which may be rhizoidal. Cells are cylindrical or barrel-shaped; the apical cell may somewhat rounded at its terminal end. The cell wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aplanospore
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Phototactic
Phototaxis is a kind of taxis, or locomotory movement, that occurs when a whole organism moves towards or away from a stimulus (physiology), stimulus of light. This is advantageous for phototrophic organisms as they can orient themselves most efficiently to receive light for photosynthesis. Phototaxis is called positive if the movement is in the direction of increasing light intensity and negative if the direction is opposite. Phototaxis has been described in microorganisms and algea, insects and other invertebrates, and vertebrates. Typically nocturnal insects can show positive phototaxis, while nocturnal mammals often show negative phototaxis. Phototaxis in bacteria and archea Phototaxis can be advantageous for phototrophic bacteria as they can orient themselves most efficiently to receive light for photosynthesis. Phototaxis is called positive if the movement is in the direction of increasing light intensity and negative if the direction is opposite. Two types of positive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eyespot Apparatus
The eyespot apparatus (or '' stigma'') is a photoreceptive organelle found in the flagellate or (motile) cells of green algae and other unicellular photosynthetic organisms such as euglenids. It allows the cells to sense light direction and intensity and respond to it, prompting the organism to either swim towards the light (positive phototaxis), or away from it (negative phototaxis). A related response ("photoshock" or photophobic response) occurs when cells are briefly exposed to high light intensity, causing the cell to stop, briefly swim backwards, then change swimming direction. Eyespot-mediated light perception helps the cells in finding an environment with optimal light conditions for photosynthesis. Eyespots are the simplest and most common "eyes" found in nature, composed of photoreceptors and areas of bright orange-red red pigment granules. Signals relayed from the eyespot photoreceptors result in alteration of the beating pattern of the flagella, generating a photo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagella
A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores ( zoospores), and from a wide range of microorganisms to provide motility. Many protists with flagella are known as flagellates. A microorganism may have from one to many flagella. A gram-negative bacterium '' Helicobacter pylori'', for example, uses its flagella to propel itself through the stomach to reach the mucous lining where it may colonise the epithelium and potentially cause gastritis, and ulcers – a risk factor for stomach cancer. In some swarming 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoospore
A zoospore is a motile asexual spore that uses a flagellum for locomotion in aqueous or moist environments. Also called a swarm spore, these spores are created by some protists, bacteria, and fungi to propagate themselves. Certain zoospores are infectious and transmittable, such as '' Batrachochytrium dendrobatidis'', a fungal zoospore that causes high rates of mortality in amphibians. Diversity General morphology Zoospores are composed of a microtubular cytoskeleton base which extends from the base of the flagellum. The complexity and structure of this cytoskeleton is variable and is largely dependent on volume and size. One common feature of zoospores is their asymmetrical shape; a result of the ventral grove housing the flagella base. Certain zoospores progress through different phases, the first phase commonly referred to as 'the initial'. Others form cysts that vary tremendously in volume (14-4905 cubic micrometers) and shape, each with distinctive hair structures. Flag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 full set of genes of their single parent and thus the newly created individual is genetically and physically similar to the parent or an exact clone of the parent. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea and eubacteria, bacteria. Many Eukaryote, eukaryotic organisms including plants, animals, and Fungus, fungi can also reproduce asexually. In Vertebrate, vertebrates, the most common form of asexual reproduction is parthenogenesis, which is typically used as an alternative to sexual reproduction in times when reproductive opportunities are limited. Some Monitor lizard, monitor lizards, including Komodo dragons, can reproduce asexually. While all prokaryotes reproduce without the fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Akinete
An akinete is an enveloped, thick-walled, non-motile, dormant cell (biology), cell formed by both cyanobacteria and algae. Cyanobacterial akinetes are mainly formed by filamentous, heterocyst-forming members under the order Nostocales and Stigonematales. Eukaryotic microalgae also produce akinetes, such as ''Haematococcus''. During akinete formation, cells accumulate and store various essential material, allowing the akinete to serve as a survival structure for up to many years. The cell akinetes are resistant to cold and desiccation. However, akinetes are not resistant to heat. Once conditions become more favorable for growth, the akinete can then germinate back into a vegetative cell. Increased light intensity, nutrients availability, oxygen availability, and changes in salinity are important triggers for germination. In cyanobacteria, akinetes usually develop in strings with each cell differentiating after another and this occurs next to heterocysts if they are present. Develo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volutin Granules
Volutin granules are an intracytoplasmic storage form of complexed inorganic polyphosphate, the production of which is used as one of the identifying criteria when attempting to isolate ''Corynebacterium diphtheriae'' on Löffler's medium. Polyphosphate granules display the metachromatic effect, appearing red when stained with methylene blue. Volutin granules can also be found in the cytoplasm of ''Saccharomyces'', a genus of ascomycete fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ....Willey, J. M., Sherwood, L. M. and Woolverton, C. J. (2011). Prescott's Microbiology, 8th Ed. McGraw Hill They are characteristic for different species and depend on the age and condition of the culture. Volutin granules (metachromatic or Babes-Ernst granules) are highly refractive, strongly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrenoid
Pyrenoids are sub-cellular phase-separated micro-compartments found in chloroplasts of many algae,Giordano, M., Beardall, J., & Raven, J. A. (2005). CO2 concentrating mechanisms in algae: mechanisms, environmental modulation, and evolution. ''Annu. Rev. Plant Biol.'', 56, 99-131. and in a single group of land plants, the hornworts.Villarreal, J. C., & Renner, S. S. (2012) Hornwort pyrenoids, carbon-concentrating structures, evolved and were lost at least five times during the last 100 million years. ''Proceedings of the National Academy of Sciences'',109(46), 1873-1887. Pyrenoids are associated with the operation of a carbon-concentrating mechanism (CCM). Their main function is to act as centres of carbon dioxide (CO2) fixation, by generating and maintaining a CO2-rich environment around the photosynthesis, photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). Pyrenoids therefore seem to have a role analogous to that of carboxysomes in cyanobacteria. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
