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Trichoplacidae
''Trichoplax adhaerens'' is one of the three named species in the phylum Placozoa. The others are '' Hoilungia hongkongensis'' and '' Polyplacotoma mediterranea''. The Placozoa is a basal group of multicellular animals (metazoa). ''Trichoplax'' are very flat organisms around a millimetre in diameter, lacking any organs or internal structures. They have two cellular layers: the top epitheloid layer is made of ciliated «cover cells» flattened toward the outside of the organism, and the bottom layer is made up of cylinder cells that possess cilia used in locomotion, and gland cells that lack cilia. Between these layers is the fibre syncytium, a liquid-filled cavity strutted open by star-like fibres. ''Trichoplax'' feed by absorbing food particles—mainly microbes—with their underside. They generally reproduce asexually, by dividing or budding, but can also reproduce sexually. Though ''Trichoplax'' has a small genome in comparison to other animals, nearly 87% of its 11,514 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placozoa
The Placozoa are a basal form of marine free-living (non-parasitic) multicellular organism. They are the simplest in structure of all animals. Three genera have been found: the classical ''Trichoplax adhaerens'', ''Hoilungia hongkongensis'', and ''Polyplacotoma mediterranea'', where the last appears most basal. The last two have been found only since 2017. Although the Placozoa were first discovered in 1883 by the German zoologist Franz Eilhard Schulze (1840–1921) and since the 1970s more systematically analyzed by the German protozoologist Karl Gottlieb Grell (1912–1994), a common name does not yet exist for the taxon; the scientific name means "flat animals". Biology ''Trichoplax'' is a small, flattened, animal around across. An amorphous multi-celled body, analogous to a single-celled ''Amoeba'', it has no regular outline, although the lower surface is somewhat concave, and the upper surface is always flattened. The body consists of an outer layer of simple epithelium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franz Eilhard Schulze
Franz Eilhard Schulze (22 March 1840 – 2 November 1921) was a German anatomist and zoologist born in Eldena, near Greifswald. Biography He studied at the Universities of Bonn and Rostock. In 1863, he received his doctorate from Rostock, where he subsequently became a lecturer of anatomy (1864) and an associate professor of comparative anatomy (1865). In 1871 he established the zoological institute at the University of Rostock.See entry oFranz Eilhard Schulzein Catalogus Professorum Rostochiensium Later on, he served as a professor at the Universities of Graz and Berlin. In 1872, he took part in the "Pomerania" expedition to the North Sea. For several years during the 1890s, he was president of the German Zoological Society (''Deutsche Zoologische Gesellschaft''). He made contributions in his studies on the anatomy and developmental history of invertebrates, in particular, his research and publications in regards to sea-sponges. He was especially interested in a class of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vie Et Milieu
Vie (IPA: /'vi.e/), is a district (or ''quarter''), of Oradea, a city in Bihor, Romania. The name means ''vineyard'' in Romanian. Geography Vie is situated in the hills overlooking Oradea, in the northern part of the town. It spans quite a large area, from a part just north of the hills but the centre extending quite far into the Oradea hills. Vie is bounded in the south by Republicii Street (''Strada Republicii''), the mainline railway tracks crossing Oradea and the Oradea central railway station (everything south of the railway station is considered part of the city centre, or ''Centru'', everything north is considered part of Vie. Infrastructure and demographics The range of infrastructure in Vie is quite broad – the southern part of the quarter, which is in proximity to the city centre, can be described as suburban, containing either low-rise houses or apartment blocks with up to five storeys. However, as one proceeds north, away from the Oradea city centre, the quarter b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungi
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from the other eukaryotic kingdoms, which by one traditional classification include Plantae, Animalia, Protozoa, and Chromista. A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the ''Eumycota'' (''t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porifera
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes. Sponges were first to branch off the evolutionary tree from the last common ancestor of all animals, making them the sister group of all other animals. Etymology The term ''sponge'' derives from the Ancient Greek word ( 'sponge'). Overview Sponges are similar to other animals in that they are multicellular, hete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of cells and organelles, being selectively permeable to ions a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Septum
In biology, a septum (Latin for ''something that encloses''; plural septa) is a wall, dividing a cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate. Examples Human anatomy * Interatrial septum, the wall of tissue that is a sectional part of the left and right atria of the heart * Interventricular septum, the wall separating the left and right ventricles of the heart * Lingual septum, a vertical layer of fibrous tissue that separates the halves of the tongue. *Nasal septum: the cartilage wall separating the nostrils of the nose * Alveolar septum: the thin wall which separates the alveoli from each other in the lungs * Orbital septum, a palpebral ligament in the upper and lower eyelids * Septum pellucidum or septum lucidum, a thin structure separating two fluid pockets in the brain * Uterine septum, a malformation of the uterus * Vaginal septum, a lateral or transverse partition inside the vagina * Intermuscular sep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digestive Enzyme
Digestive enzymes are a group of enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption into the cells of the body. Digestive enzymes are found in the digestive tracts of animals (including humans) and in the tracts of carnivorous plants, where they aid in the digestion of food, as well as inside cells, especially in their lysosomes, where they function to maintain cellular survival. Digestive enzymes of diverse specificities are found in the saliva secreted by the salivary glands, in the secretions of cells lining the stomach, in the pancreatic juice secreted by pancreatic exocrine cells, and in the secretions of cells lining the small and large intestines. Digestive enzymes are classified based on their target substrates: * Lipases split fatty acids into fats and oils. *Proteases and peptidases split proteins into small peptides and amino acids. *Amylases split carbohydrates such as starch and sugars into s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipid
Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes. Lipids have applications in the cosmetic and food industries, and in nanotechnology. Lipids may be broadly defined as hydrophobic or amphiphilic small molecules; the amphiphilic nature of some lipids allows them to form structures such as vesicles, multilamellar/unilamellar liposomes, or membranes in an aqueous environment. Biological lipids originate entirely or in part from two distinct types of biochemical subunits or "building-blocks": ketoacyl and isoprene groups. Using this approach, lipids may be divided into eight categories: fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, and polyketides (derived from condensati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Lamina
The basal lamina is a layer of extracellular matrix secreted by the epithelial cells, on which the epithelium sits. It is often incorrectly referred to as the basement membrane, though it does constitute a portion of the basement membrane. The basal lamina is visible only with the electron microscope, where it appears as an electron-dense layer that is 20–100 nm thick (with some exceptions that are thicker, such as basal lamina in lung alveoli and renal glomeruli). Structure The layers of the basal lamina ("BL") and those of the basement membrane ("BM") are described below: Anchoring fibrils composed of type VII collagen extend from the basal lamina into the underlying reticular lamina and loop around collagen bundles. Although found beneath all basal laminae, they are especially numerous in stratified squamous cells of the skin. These layers should not be confused with the lamina propria, which is found outside the basal lamina. Basement membrane The basement membra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epithelium
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellular matrix. Epithelial tissues line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs. An example is the epidermis, the outermost layer of the skin. There are three principal shapes of epithelial cell: squamous (scaly), columnar, and cuboidal. These can be arranged in a singular layer of cells as simple epithelium, either squamous, columnar, or cuboidal, or in layers of two or more cells deep as stratified (layered), or ''compound'', either squamous, columnar or cuboidal. In some tissues, a layer of columnar cells may appear to be stratified due to the placement of the nuclei. This sort of tissue is called pseudostratified. All glands are made up of epithe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desmosome
A desmosome (; "binding body"), also known as a macula adherens (plural: maculae adherentes) (Latin for ''adhering spot''), is a cell structure specialized for cell-to-cell adhesion. A type of junctional complex, they are localized spot-like adhesions randomly arranged on the lateral sides of plasma membranes. Desmosomes are one of the stronger cell-to-cell adhesion types and are found in tissue that experience intense mechanical stress, such as cardiac muscle tissue, bladder tissue, gastrointestinal mucosa, and epithelia. Structure Desmosomes are composed of desmosome-intermediate filament complexes (DIFC), which is a network of cadherin proteins, linker proteins and intermediate filaments. The DIFCs can be broken into three regions: the extracellular core region, or desmoglea, the outer dense plaque, or ODP, and the inner dense plaque, or IDP. The extracellular core region, approximately 34 nm in length, contains desmoglein and desmocollin, which are in the cadherin famil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
