|
Gonium Viridistellatum
''Gonium'' (Greek: γωνία ''gonia'', "angle" or "corner") is a genus of colonial green algae, a member of the order Chlamydomonadales. The genus was first described by Otto Friedrich Müller in 1773, and is among the most common types of algae found in freshwater habitats. It has a cosmopolitan distribution. Typical colonies of ''Gonium'' consist of 4 to 16 cells arranged in a flat plate. ''Gonium'' is capable of both asexual and sexual reproduction. Along with other algae such as ''Volvox'', '' Eudorina'' and ''Chlamydomonas'', it is a model organism for studying the origins and evolution of multicellularity. Description ''Gonium'' consists of flat, planar colonies of four to 32 cells, all identical with the colony having no anterior-posterior differentiation. In one species ''Gonium dispersum'', single cells may also be found. 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): ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonium Angulatum
''Gonium'' (Ancient Greek, Greek: γωνία ''gonia'', "angle" or "corner") is a genus of colonial green algae, a member of the order Chlamydomonadales. The genus was first described by Otto Friedrich Müller in 1773, and is among the most common types of algae found in freshwater habitats. It has a cosmopolitan distribution. Typical colonies of ''Gonium'' consist of 4 to 16 cells arranged in a flat plate. ''Gonium'' is capable of both asexual reproduction, asexual and sexual reproduction. Along with other algae such as ''Volvox'', ''Eudorina'' and ''Chlamydomonas'', it is a model organism for studying the origins and evolution of multicellularity. Description ''Gonium'' consists of flat, planar colonies of four to 32 cells, all identical with the colony having no anterior-posterior differentiation. In one species ''Gonium dispersum'', single cells may also be found. In a colony of 16 cells, four are in the center, and the other 12 are on the four sides, three each. A descripti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmopolitan Distribution
In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and environmental conditions, though this is not always so. Killer whales ( orcas) are among the most well-known cosmopolitan species on the planet, as they maintain several different resident and transient (migratory) populations in every major oceanic body on Earth, from the Arctic Circle to Antarctica and every coastal and open-water region in-between. Such a taxon (usually a species) is said to have a ''cosmopolitan'' distribution, or exhibit cosmopolitanism, as a species; another example, the rock dove (commonly referred to as a ' pigeon'), in addition to having been bred domestically for centuries, now occurs in most urban areas around the world. The extreme opposite of a cosmopolitan species is an endemic (native) species, or one foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuole
A vacuole () is a membrane-bound organelle which is present in Plant cell, plant and Fungus, fungal Cell (biology), cells and some protist, animal, and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in Solutes, solution, though in certain cases they may contain solids which have been engulfed. Vacuoles are formed by the fusion of multiple membrane Vesicle (biology), vesicles and are effectively just larger forms of these. The organelle has no basic shape or size; its structure varies according to the requirements of the cell. Discovery Antonie van Leeuwenhoek described the plant vacuole in 1676. Contractile vacuoles ("stars") were first observed by Spallanzani (1776) in protozoa, although mistaken for respiratory organs. Félix Dujardin, Dujardin (1841) named these "stars" as ''vacuoles''. In 1842, Matthias Jakob Schleiden, Schleiden applied the term for plant cells, to dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cilia
The cilium (: cilia; ; in Medieval Latin and in anatomy, ''cilium'') is a short hair-like membrane protrusion from many types of eukaryotic cell. (Cilia are absent in bacteria and archaea.) The cilium has the shape of a slender threadlike projection that extends from the surface of the much larger cell body. Eukaryotic flagella found on sperm cells and many protozoans have a similar structure to motile cilia that enables swimming through liquids; they are longer than cilia and have a different undulating motion. There are two major classes of cilia: ''motile'' and ''non-motile'' cilia, each with two subtypes, giving four types in all. A cell will typically have one primary cilium or many motile cilia. The structure of the cilium core, called the axoneme, determines the cilium class. Most motile cilia have a central pair of single microtubules surrounded by nine pairs of double microtubules called a 9+2 axoneme. Most non-motile cilia have a 9+0 axoneme that lacks the central pai ... [...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] |
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] |
Pyriform
Piriform, sometimes ''pyriform'', means pear-shaped (from Latin ''pirum'' "pear" and ''forma'' "shape"). It may also refer to: Anatomy * Piriform aperture, more commonly known as anterior nasal aperture * Piriform cortex, a region in the brain * Piriformis muscle, a gluteal muscle ** Piriformis syndrome, a neuromuscular disorder in which the piriformis muscle compresses the sciatic nerve * Piriform sinus, piriform recess or piriform fossa, synonyms referring to one of the four sites of the hypopharynx * The (notionally) pear-like female body shape (gynoid shape) ** Pear-shaped obesity (adiposity highest on hips and thighs), in contrast with apple-shaped obesity (central adiposity, abdominal obesity) Other uses * Piriform Software, a software company * Piriform, in hydrostatic equilibrium In fluid mechanics, hydrostatic equilibrium, also called hydrostatic balance and hydrostasy, is the condition of a fluid or plastic solid at rest, which occurs when external forces, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Wiley & Sons
John Wiley & Sons, Inc., commonly known as Wiley (), is an American Multinational corporation, multinational Publishing, publishing company that focuses on academic publishing and instructional materials. The company was founded in 1807 and produces books, Academic journal, journals, and encyclopedias, in print and electronically, as well as online products and services, training materials, and educational materials for undergraduate, graduate, and continuing education students. History The company was established in 1807 when Charles Wiley opened a print shop in Manhattan. The company was the publisher of 19th century American literary figures like James Fenimore Cooper, Washington Irving, Herman Melville, and Edgar Allan Poe, as well as of legal, religious, and other non-fiction titles. The firm took its current name in 1865. Wiley later shifted its focus to scientific, Technology, technical, and engineering subject areas, abandoning its literary interests. Wiley's son Joh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multicellularity
A multicellular organism is an organism that consists of more than one cell, unlike unicellular organisms. All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- and partially multicellular, like slime molds and social amoebae such as the genus '' Dictyostelium''. Multicellular organisms arise in various ways, for example by cell division or by aggregation of many single cells. Colonial organisms are the result of many identical individuals joining together to form a colony. However, it can often be hard to separate colonial protists from true multicellular organisms, because the two concepts are not distinct; colonial protists have been dubbed "pluricellular" rather than "multicellular". There are also macroscopic organisms that are multinucleate though technically unicellular, such as the Xenophyophorea that can reach 20 cm. Evolutionary history Occurrence Multicellularity has evolved ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Model Organism
A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. Model organisms are widely used to research human disease when human experimentation would be unfeasible or unethical. This strategy is made possible by the common descent of all living organisms, and the conservation of metabolic and developmental pathways and genetic material over the course of evolution. Research using animal models has been central to most of the achievements of modern medicine. It has contributed most of the basic knowledge in fields such as human physiology and biochemistry, and has played significant roles in fields such as neuroscience and infectious disease. The results have included the near- eradication of polio and the development of organ transplantation, and have benefited both humans and animals. From 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlamydomonas
''Chlamydomonas'' ( ) is a genus of green algae consisting of about 150 species of unicellular organism, unicellular flagellates, found in stagnant water and on damp soil, in freshwater, seawater, and even in snow as "snow algae". ''Chlamydomonas'' is used as a model organism for molecular biology, especially studies of flagellum, flagellar motility and chloroplast dynamics, biogenesis, and genetics. One of the many striking features of ''Chlamydomonas'' is that it contains ion channels (channelrhodopsins) that are directly activated by light. Some FLU (plant gene), regulatory systems of ''Chlamydomonas'' are more complex than their Homology (biology), homologs in Gymnosperms, with evolutionarily related Regulation of gene expression, regulatory proteins being larger and containing additional Protein domain, domains. Molecular phylogeny studies indicated that the traditional genus ''Chlamydomonas'' as defined using morphological data, was polyphyletic within Volvocales. Many s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eudorina
''Eudorina'' is a genus of green algae in the family Volvocaceae, containing about seven species. It has a cosmopolitan distribution in freshwater habitats. Description ''Eudorina'' colonies typically consist of 16, 32 or 64 cells, each of which is similar to '' Chlamydomonas reinhardtii''. These cells are bedded within an extracellular matrix composed of glycoproteins. Colonies are spherical and motile, with motility derived from the flagellated individual cells. Cells are ovoid or spherical, each with two equal flagella. (In one species '' Eudorina compacta'', the cells essentially touch each other, and are strikingly angular due to mutual compression.) There is a single cup-shaped chloroplast with one (basal) or multiple pyrenoids) and a stigma. Multiple contractile vacuoles are scattered throughout the cytoplasm. ''Eudorina'' is facultatively sexual, meaning colonies can reproduce either sexually or asexually. During development, each ''Chlamydomonas''-like cell undergoe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
