|
Turritopsis Dohrnii
''Turritopsis dohrnii'', also known as the immortal jellyfish, is a species of small, biological immortality, biologically immortal jellyfish found worldwide in temperate to tropic waters. It is one of the few known cases of animals capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary individual. Others include the jellyfish ''Laodicea undulata'' and species of the genus ''Aurelia (cnidarian), Aurelia''. Like most other hydrozoans, ''T. dohrnii'' begin their lives as tiny, free-swimming larvae known as planulae. As a planula settles down, it gives rise to a colony of polyp (zoology), polyps that are attached to the Seabed, sea floor. All the polyps and jellyfish arising from a single planula are genetically identical clones. The polyps form into an extensively branched form, which is not commonly seen in most jellyfish. Jellyfish, also known as medusae, then bud off these polyps and continue their life in a fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
August Weismann
August Friedrich Leopold Weismann FRS (For), HonFRSE, LLD (17 January 18345 November 1914) was a German evolutionary biologist. Fellow German Ernst Mayr ranked him as the second most notable evolutionary theorist of the 19th century, after Charles Darwin. Weismann became the Director of the Zoological Institute and the first Professor of Zoology at Freiburg. His main contribution involved germ plasm theory, at one time also known as Weismannism,Romanes, George John. ''An examination of Weismannism''. The Open court publishing company in Chicago 189/ref> according to which inheritance (in a multicellular animal) only takes place by means of the germ cells—the gametes such as egg cells and sperm cells. Other cells of the body—somatic cells—do not function as agents of heredity. The effect is one-way: germ cells produce somatic cells and are not affected by anything the somatic cells learn or therefore any ability an individual acquires during its life. Genetic information c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Specificity
Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organisms or constituents of living organisms of being special or doing something special. Each animal or plant species is special. It differs in some way from all other species...biological specificity is the major problem about understanding life." Biological specificity within ''Homo sapiens'' ''Homo sapiens'' has many characteristics that show the biological specificity in the form of behavior and morphological traits. Morphologically, humans have an enlarged cranial capacity and more gracile features in comparison to other hominins. The reduction of dentition is a feature that allows for the advantage of adaptability in diet and survival. As a species, humans are culture dependent and much of human survival relies on the culture and so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smithsonian Tropical Research Institute
The Smithsonian Tropical Research Institute (STRI, es, Instituto Smithsonian de Investigaciones Tropicales) is located in Panama and is the only bureau of the Smithsonian Institution based outside of the United States. It is dedicated to understanding the past, present, and future of tropical ecosystems and their relevance to human welfare. STRI grew out of a small field station established in 1923 on Barro Colorado Island in the Panama Canal Zone to become one of the world's leading tropical research organizations. STRI's facilities provide for long-term ecological studies in the tropics and are used by some 1,200 visiting scientists from academic and research institutions around the world every year. History Smithsonian scientists first came to Panama during the construction of the Panama Canal from 1904 to 1914. The Secretary of the Smithsonian Institution, Charles Doolittle Walcott, reached an agreement with Federico Boyd to conduct a biological inventory of the new Canal Zo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballast Water Discharge And The Environment
Ballast water discharges by ships can have a negative impact on the marine environment. The discharge of ballast water and sediments by ships is governed globally under the Ballast Water Management Convention, since its entry into force in September 2017. It is also controlled through national regulations, which may be separate from the Convention, such as in the United States. Cruise ships, large tankers, and bulk cargo carriers use a huge amount of ballast water, which is often taken on in the coastal waters in one region after ships discharge wastewater or unload cargo, and discharged at the next port of call, wherever more cargo is loaded. Ballast water discharge typically contains a variety of biological materials, including plants, animals, viruses, and bacteria. These materials often include non-native, nuisance, exotic species that can cause extensive ecological and economic damage to aquatic ecosystems, along with serious human health issues including death. Problemat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Times Online
''The Times'' is a British daily national newspaper based in London. It began in 1785 under the title ''The Daily Universal Register'', adopting its current name on 1 January 1788. ''The Times'' and its sister paper ''The Sunday Times'' (founded in 1821) are published by Times Newspapers, since 1981 a subsidiary of News UK, in turn wholly owned by News Corp. ''The Times'' and ''The Sunday Times'', which do not share editorial staff, were founded independently and have only had common ownership since 1966. In general, the political position of ''The Times'' is considered to be centre-right. ''The Times'' is the first newspaper to have borne that name, lending it to numerous other papers around the world, such as ''The Times of India'', ''The New York Times'', and more recently, digital-first publications such as TheTimesBlog.com (Since 2017). In countries where these other titles are popular, the newspaper is often referred to as , or as , although the newspaper is of national ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telegraph Media Group
Telegraph Media Group Limited (TMG; previously the Telegraph Group) is the proprietor of ''The Daily Telegraph'' and ''The Sunday Telegraph''. It is a subsidiary of Press Holdings. David and Frederick Barclay acquired the group on 30 July 2004, after months of intense bidding and lawsuits, from Hollinger Inc. of Toronto, Canada, the newspaper group controlled by the Canadian/American businessman Conrad Black. In 2015, TMG made an operating profit of £51 million. Profits before tax were £47m, and turnover for the 53 weeks up to 3 January 2016 was £319m, according to unaudited accounts leaked to ''The Guardian''. If these figures are accurate, then this was an increase from 2014 levels on both accounts. Telegraph Media Group operates as a multimedia news company. The holding publishes daily and weekly publications in printed and electronic versions, which provide news on politics, obituaries, sports, finance, lifestyle, travel, health, culture, technology, fashion and cars. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphology (biology)
Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, colour, pattern, size), i.e. external morphology (or eidonomy), as well as the form and structure of the internal parts like bones and organs, i.e. internal morphology (or anatomy). This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of gross structure of an organism or taxon and its component parts. History The etymology of the word "morphology" is from the Ancient Greek (), meaning "form", and (), meaning "word, study, research". While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Friedrich Burdach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turritopsis Rubra
''Turritopsis rubra,'' sometimes known as the crimson jelly, is a species of hydrozoan of the family Oceaniidae. Medusae of such species are informally called jellyfish. Description Adult medusae are energetic swimmers. They are 3–7 mm in diameter, with a bell-shaped, transparent umbrella. The margin of the umbrella has a fringe of up to 120 closely-spaced, long, thin tentacles which coil up or extend out in strings to catch small planktonic animals to feed on. The tentacles have adaxial ocelli. The bright red or red-orange stomach and the gonads can be seen. They cannot sting humans as their stings are too small. @ 10:36 Life cycle As a hydrozoan, ''T. rubra'' has two distinct stages in their life, a polyp stage and a medusa stage. Polyps grow in benthic colonies and asexually reproduce to create medusae, which are free-swimming, dieocious, and reproduce sexually. Female medusae brood their larvae, sometimes up to the primary polyp stage. The larvae are small and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stolon
In biology, stolons (from Latin '' stolō'', genitive ''stolōnis'' – "branch"), also known as runners, are horizontal connections between organisms. They may be part of the organism, or of its skeleton; typically, animal stolons are external skeletons. In botany In botany, stolons are stems which grow at the soil surface or just below ground that form adventitious roots at the nodes, and new plants from the buds. Stolons are often called runners. Rhizomes, in contrast, are root-like stems that may either grow horizontally at the soil surface or in other orientations underground. Thus, not all horizontal stems are called stolons. Plants with stolons are called stoloniferous. A stolon is a plant propagation strategy and the complex of individuals formed by a mother plant and all its clones produced from stolons form a single genetic individual, a genet. Morphology Stolons may or may not have long internodes. The leaves along the stolon are usually very small, but in a few ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidermis
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water released from the body into the atmosphere through transepidermal water loss. The epidermis is composed of multiple layers of flattened cells that overlie a base layer (stratum basale) composed of columnar cells arranged perpendicularly. The layers of cells develop from stem cells in the basal layer. The human epidermis is a familiar example of epithelium, particularly a stratified squamous epithelium. The word epidermis is derived through Latin , itself and . Something related to or part of the epidermis is termed epidermal. Structure Cellular components The epidermis primarily consists of keratinocytes ( proliferating basal and differentiated suprabasal), which comprise 90% of its cells, but also contains melanocytes, Langerhans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerve Net
A nerve net consists of interconnected neurons lacking a brain or any form of cephalization. While organisms with bilateral body symmetry are normally associated with a condensation of neurons or, in more advanced forms, a central nervous system, organisms with radial symmetry are associated with nerve nets, and are found in members of the Ctenophora, Cnidaria, and Echinodermata phyla, all of which are found in marine environments. In the Xenacoelomorpha, a phylum of bilaterally symmetrical animals, members of the subphylum Xenoturbellida also possess a nerve net. Nerve nets can provide animals with the ability to sense objects through the use of the sensory neurons within the nerve net. It also exists in several other phyla, like chordates, annelids and flatworms, but then always alongside with longitudinal nerve(s) and/or a brain. The nerve net is the simplest form of a nervous system found in multicellular organisms. Unlike central nervous systems, where neurons are typica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesoglea
Mesoglea refers to the extracellular matrix found in cnidarians like coral or jellyfish that functions as a hydrostatic skeleton. It is related to but distinct from mesohyl, which generally refers to extracellular material found in sponges. Description The mesoglea is mostly water. Other than water, the mesoglea is composed of several substances including fibrous proteins, like collagen and heparan sulphate proteoglycans. The mesoglea is mostly acellular, but in both cnidaria and ctenophora the mesoglea contains muscle bundles and nerve fibres. Other nerve and muscle cells lie just under the epithelial layers. The mesoglea also contains wandering amoebocytes that play a role in phagocytosing debris and bacteria. These cells also fight infections by producing antibacterial chemicals. The mesoglea may be thinner than either of the cell layers in smaller coelenterates like a hydra or may make up the bulk of the body in larger jellyfish. The mesoglea serves as an internal skeleton, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
