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Hexactinellida Genera
Hexactinellid sponges are sponges with a skeleton made of four- and/or six-pointed siliceous spicules, often referred to as glass sponges. They are usually classified along with other sponges in the phylum Porifera, but some researchers consider them sufficiently distinct to deserve their own phylum, Symplasma. Some experts believe that glass sponges are the longest-lived animals on earth; these scientists tentatively estimate a maximum age of up to 15,000 years. Biology Glass sponges are relatively uncommon and are mostly found at depths from below sea level. Although the species '' Oopsacas minuta'' has been found in shallow water, others have been found much deeper. They are found in all oceans of the world, although they are particularly common in Antarctic and Northern Pacific waters. They are more-or-less cup-shaped animals, ranging from in height, with sturdy skeletons made of glass-like silica spicules, fused to form a lattice. In some glass sponges such as memb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ediacaran
The Ediacaran ( ) is a geological period of the Neoproterozoic geologic era, Era that spans 96 million years from the end of the Cryogenian Period at 635 Million years ago, Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last period of the Proterozoic geologic eon, Eon as well as the last of the so-called "Precambrian supereon", before the beginning of the subsequent Cambrian Period marks the start of the Phanerozoic Eon, where recognizable fossil evidence of life becomes common. The Ediacaran Period is named after the Ediacara Hills of South Australia, where trace fossils of a diverse community of previously unrecognized lifeforms (later named the Ediacaran biota) were first discovered by geologist Reg Sprigg in 1946. Its status as an official geological period was ratified in 2004 by the International Union of Geological Sciences (IUGS), making it the first new geological period declared in 120 years. Although the period took namesake from the Ediacara Hills ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syncytium
A syncytium (; : syncytia; from Greek: σύν ''syn'' "together" and κύτος ''kytos'' "box, i.e. cell") or symplasm is a multinucleate cell that can result from multiple cell fusions of uninuclear cells (i.e., cells with a single nucleus), in contrast to a coenocyte, which can result from multiple nuclear divisions without accompanying cytokinesis. The muscle cell that makes up animal skeletal muscle is a classic example of a syncytium cell. The term may also refer to cells interconnected by specialized membranes with gap junctions, as seen in the heart muscle cells and certain smooth muscle cells, which are synchronized electrically in an action potential. The field of embryogenesis uses the word ''syncytium'' to refer to the coenocytic blastoderm embryos of invertebrates, such as ''Drosophila melanogaster''. Physiological examples Protists In protists, syncytia can be found in some rhizarians (e.g., chlorarachniophytes, plasmodiophorids, haplosporidians) and acellul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venus Flower Basket
The Venus' flower basket (''Euplectella aspergillum'') is a species of glass sponge found in the deep waters of the Pacific Ocean, usually at depths below . Like other glass sponges, they build their skeletons out of silica, which forms a unique lattice structure consisting of spicules. This body structure is of great interest in materials science as the optical and mechanical properties are in some ways superior to man-made materials. Like other sponges, they feed by filtering sea water to capture plankton and marine snow. Little is known regarding their reproductive habits, though the fluid dynamics of their body structure likely influence reproduction and it is hypothesized that they may be hermaphroditic. Taxonomy ''Euplectella aspergillum'' was described in 1841 by Sir Richard Owen. As the genus ''Euplectella'' was named to accommodate this species, it is the type of its genus. Owen describes it as "...one of the most singular and beautiful, as well as the rarest of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sclerocyte
Sclerocytes are specialised cells that secrete the mineralized structures in the body wall of some invertebrates. In sponges they secrete calcareous or siliceous spicules which are found in the mesohyl layer of sponges. The sclerocytes produce spicules via formation of a cellular triad. The triad of cells then undergo mitosis, creating six sclerocytes. In pairs, the sclerocytes secrete the minerals which create the spicules. In starfish they are present in the dermis and secrete the calcite microcrystals from which the ossicles are formed. They also function in growth and repair of the ossicles The ossicles (also called auditory ossicles) are three irregular bones in the middle ear of humans and other mammals, and are among the smallest bones in the human body. Although the term "ossicle" literally means "tiny bone" (from Latin ''ossi .... References Sponge anatomy Animal cells {{Sponge-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organelle
In cell biology, an organelle is a specialized subunit, usually within a cell (biology), cell, that has a specific function. The name ''organelle'' comes from the idea that these structures are parts of cells, as Organ (anatomy), organs are to the Human body, body, hence ''organelle,'' the suffix ''-elle'' being a diminutive. Organelles are either separately enclosed within their own lipid bilayers (also called membrane-bounded organelles) or are spatially distinct functional units without a surrounding lipid bilayer (non-membrane bounded organelles). Although most organelles are functional units within cells, some functional units that extend outside of cells are often termed organelles, such as cilia, the flagellum and archaellum, and the trichocyst (these could be referred to as membrane bound in the sense that they are attached to (or bound to) the membrane). Organelles are identified by microscopy, and can also be purified by cell fractionation. There are many types of organe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scaffolding
Scaffolding, also called scaffold or staging, is a temporary structure used to support a work crew and materials to aid in the construction, maintenance and repair of buildings, bridges and all other human-made structures. Scaffolds are widely used on site to get access to heights and areas that would be otherwise hard to get to. Unsafe scaffolding has the potential to result in death or serious injury. Scaffolding is also used in adapted forms for formwork and shoring, grandstand seating, concert stages, access/viewing towers, exhibition stands, ski ramps, half pipes and art projects. There are six main types of scaffolding used worldwide today. These are tube and coupler (fitting) components, prefabricated modular system scaffold components, H-frame / façade modular system scaffolds, suspended scaffolds, timber scaffolds and bamboo scaffolds (particularly in China, India and Hong Kong). Each type is made from several components which often include: * A base jack or plate whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spider Web
A spider web, spiderweb, spider's web, or cobweb (from the archaic word ''Wikt:coppe, coppe'', meaning 'spider') is a structure created by a spider out of proteinaceous spider silk extruded from its spinnerets, generally meant to catch its prey. Spider webs have existed for at least 100 million years, as witnessed in a rare find of Early Cretaceous amber from Sussex, in southern England. Many spiders build webs specifically to trap and catch insects to eat. However, not all spiders catch their prey in webs, and some do not build webs at all. The term "spider web" is typically used to refer to a web that is apparently still in use (i.e., clean), whereas "cobweb" refers to a seemingly abandoned (i.e., dusty) web. However, the word "cobweb" is also used by biologists to describe the tangled three-dimensional web of some spiders of the family Theridiidae. While this large family is known as the cobweb spiders, they actually have a huge range of web architectures; other names for thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Nucleus
The cell nucleus (; : nuclei) is a membrane-bound organelle found in eukaryote, eukaryotic cell (biology), cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have #Anucleated_cells, no nuclei, and a few others including osteoclasts have Multinucleate, many. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm; and the nuclear matrix, a network within the nucleus that adds mechanical support. The cell nucleus contains nearly all of the cell's genome. Nuclear DNA is often organized into multiple chromosomes – long strands of DNA dotted with various proteins, such as histones, that protect and organize the DNA. The genes within these chromosomes are Nuclear organization, structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syncytium
A syncytium (; : syncytia; from Greek: σύν ''syn'' "together" and κύτος ''kytos'' "box, i.e. cell") or symplasm is a multinucleate cell that can result from multiple cell fusions of uninuclear cells (i.e., cells with a single nucleus), in contrast to a coenocyte, which can result from multiple nuclear divisions without accompanying cytokinesis. The muscle cell that makes up animal skeletal muscle is a classic example of a syncytium cell. The term may also refer to cells interconnected by specialized membranes with gap junctions, as seen in the heart muscle cells and certain smooth muscle cells, which are synchronized electrically in an action potential. The field of embryogenesis uses the word ''syncytium'' to refer to the coenocytic blastoderm embryos of invertebrates, such as ''Drosophila melanogaster''. Physiological examples Protists In protists, syncytia can be found in some rhizarians (e.g., chlorarachniophytes, plasmodiophorids, haplosporidians) and acellul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venus' Flower Basket
The Venus' flower basket (''Euplectella aspergillum'') is a species of glass sponge found in the deep waters of the Pacific Ocean, usually at depths below . Like other glass sponges, they build their skeletons out of silica, which forms a unique lattice structure consisting of spicules. This body structure is of great interest in materials science as the optical and mechanical properties are in some ways superior to man-made materials. Like other sponges, they feed by filtering sea water to capture plankton and marine snow. Little is known regarding their reproductive habits, though the fluid dynamics of their body structure likely influence reproduction and it is hypothesized that they may be hermaphroditic. Taxonomy ''Euplectella aspergillum'' was described in 1841 by Sir Richard Owen. As the genus ''Euplectella'' was named to accommodate this species, it is the type of its genus. Owen describes it as "...one of the most singular and beautiful, as well as the rarest of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euplectella 01
''Euplectella'' is a genus of glass sponges which includes the well-known Venus' Flower Basket The Venus' flower basket (''Euplectella aspergillum'') is a species of glass sponge found in the deep waters of the Pacific Ocean, usually at depths below . Like other glass sponges, they build their skeletons out of silica, which forms a unique .... Glass sponges have a skeleton made up of silica spicules that can form geometric patterns. These animals are most commonly found on muddy sea bottoms in the Western Pacific and Indian Oceans. They are sessile organisms and do not move once attached to a rock. They can be found at depths between 100 m and 1000 m but are most commonly found at depths greater than 500 m. Anatomy ''Euplectella'' is a member of the class Sclerospongiae or glass sponges. The body shape of ''Euplectella'' is cylindrical and vase-like with a hole located at the top of the cylinder structure. This tubular shape is referred to as asconoid. The inner structure o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choanosome
A choanosome is an inner region of a sponge, supported on the choanoskeleton, the structure that contains the choanocytes. See also * Choanoderm The choanoderm is a type of cell layer composed of flagellated collar cells, or choanocytes, found in sponges. The sponge body is mostly a connective tissue; the mesohyl, over which are applied epithelioid monolayers of cells, the outer pinaco ... Sponge anatomy References {{biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
