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Haplopoda
''Leptodora'' is a genus containing two species of large, nearly transparent predatory water fleas. They grow up to long, with two large antennae used for swimming and a single compound eye. The legs are used to catch copepods that it comes into contact with by chance. ''Leptodora kindtii'' is found in temperate lakes across the Northern Hemisphere and is probably the only water flea species ever described in a newspaper; ''L. richardi'' is only known from eastern Russia. For most of the year, ''Leptodora'' reproduces parthenogenetically, with males only appearing late in the season, to produce winter eggs which hatch the following spring. ''Leptodora'' is the only genus in its family, the Leptodoridae, and suborder, Haplopoda. Description Adults of ''Leptodora'' are the largest planktonic cladocerans native to North America; reports vary concerning the largest size, but adult females typically grow to long, but with some reports of females up to . They are about 98% transpa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Flea
The Diplostraca or Cladocera, commonly known as water fleas, is a superorder of small, mostly freshwater crustaceans, most of which feed on microscopic chunks of organic matter, though some forms are predatory. Over 1000 species have been recognised so far, with many more undescribed. The oldest fossils of diplostracans date to the Jurassic, though their modern morphology suggests that they originated substantially earlier, during the Paleozoic. Some have also adapted to a life in the ocean, the only members of Branchiopoda to do so, though several anostracans live in hypersaline lakes. Most are long, with a down-turned head with a single median compound eye, and a carapace covering the apparently unsegmented thorax and abdomen. Most species show cyclical parthenogenesis, where asexual reproduction is occasionally supplemented by sexual reproduction, which produces resting eggs that allow the species to survive harsh conditions and disperse to distant habitats. Description ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georg Ossian Sars
Prof Georg Ossian Sars HFRSE (20 April 1837 – 9 April 1927) was a Norway, Norwegian marine biology, marine and freshwater biology, freshwater biologist. Life Georg Ossian Sars was born on 20 April 1837 in Kinn (former municipality), Kinn, Norway (now part of Flora, Norway, Flora), the son of Pastor Michael Sars and Maren Sars; the historian Ernst Sars was his elder brother, and the singer and women's skiing pioneer Eva Nansen was his younger sister.Google Translate He grew up in Manger, Norway, Manger, Hordaland, where his father was the local priest. He studied from 1852 to 1854 at Bergen Cathedral School, from 1854 at Oslo Cathedral School, Christiania Cathedral School, and joined the university at Christiana (now the University of Oslo) in 1857. He indulged his interest in natural history while studying medicine; having collected water fleas in local lakes with Wilhelm Lilljeborg's works, he discovered new species, and this resulted in his first scientific publication. Geor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Michigan University
Central Michigan University (CMU) is a Public university, public research university in Mount Pleasant, Michigan, United States. It was established in 1892 as a private normal school and became a state institution in 1895. CMU is one of the eight research universities in Michigan and is Carnegie Classification of Institutions of Higher Education, classified among "R2: Doctoral Universities – High research activity". It has more than 15,000 students on its Mount Pleasant campus. CMU offers 200 academic programs at the undergraduate, master's, specialist, and doctoral levels. The Central Michigan Chippewas compete in the NCAA Division I Mid-American Conference in six men's and ten women's sports. History CMU opened in 1892 as the Central Michigan Normal School and Business Institute. Prof. Charles F. R. Bellows, a University of Michigan graduate, became the founding principal of the school in June 1892. For the first year, 31 students attended classes in the Carpenter Buildi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oklahoma
Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northeast, Arkansas to the east, New Mexico to the west, and Colorado to the northwest. Partially in the western extreme of the Upland South, it is the List of U.S. states and territories by area, 20th-most extensive and the List of U.S. states and territories by population, 28th-most populous of the 50 United States. Its residents are known as Oklahomans and its capital and largest city is Oklahoma City. The state's name is derived from the Choctaw language, Choctaw words , 'people' and , which translates as 'red'. Oklahoma is also known informally by its List of U.S. state and territory nicknames, nickname, "The Sooner State", in reference to the Sooners, American pioneer, American settlers who staked their claims in formerly American Indian-o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texas
Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the west, and has Mexico-United States border, an international border with the Mexican states of Chihuahua (state), Chihuahua, Coahuila, Nuevo León, and Tamaulipas to the south and southwest. Texas has Texas Gulf Coast, a coastline on the Gulf of Mexico to the southeast. Covering and with over 31 million residents as of 2024, it is the second-largest state List of U.S. states and territories by area, by area and List of U.S. states and territories by population, population. Texas is nicknamed the ''Lone Star State'' for its former status as the independent Republic of Texas. Spain was the first European country to Spanish Texas, claim and control Texas. Following French colonization of Texas, a short-lived colony controlled by France, Mexico ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the south and west by the Pacific Ocean. The region includes Middle America (Americas), Middle America (comprising the Caribbean, Central America, and Mexico) and Northern America. North America covers an area of about , representing approximately 16.5% of Earth's land area and 4.8% of its total surface area. It is the third-largest continent by size after Asia and Africa, and the list of continents and continental subregions by population, fourth-largest continent by population after Asia, Africa, and Europe. , North America's population was estimated as over 592 million people in list of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's popula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Cell Biology
The ''Journal of Cell Biology'' is a peer-reviewed scientific journal published by Rockefeller University Press. History In the early 1950s, a small group of biologists began to explore intracellular anatomy using the emerging technology of electron microscopy. Many of these researchers were at The Rockefeller Institute of Medicine, the predecessor of The Rockefeller University. As their work progressed to publication, they were disappointed with the limited quality of halftone image reproduction in the printed journals of the time, and frustrated by the narrow editorial policies of existing journals regarding their image-based results. In 1954, the Director of the Rockefeller Institute, Detlev Bronk, convened a luncheon to discuss the creation of a new journal as a venue for publication of this type of work. The first issue of ''The Journal of Biophysical and Biochemical Cytology'' was published less than a year later on January 25, 1955. A subscription cost $15 per year. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Facet
Facets () are flat faces on geometric shapes. The organization of naturally occurring facets was key to early developments in crystallography, since they reflect the underlying symmetry of the crystal structure. Gemstones commonly have facets cut into them in order to improve their appearance by allowing them to reflect light. The earliest diamond cutting techniques were simply to polish the natural shape of rough diamonds, often octahedral crystals. It wasn't until the 14th century that faceting, the process of cutting and polishing a gemstone to create multiple flat surfaces or facets, was first developed in Europe. Facet arrangements Of the hundreds of facet arrangements that have been used, the most famous is probably the round brilliant cut, used for diamond and many colored gemstones. This first early version of what would become the modern Brilliant Cut is said to have been devised by an Italian named Peruzzi, sometime in the late 17th century.Gems, 5th edition, Webster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Reproduction
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes ( diploid). This is typical in animals, though the number of chromosome sets and how that number changes in sexual reproduction varies, especially among plants, fungi, and other eukaryotes. In placental mammals, sperm cells exit the penis through the male urethra and enter the vagina during copulation, while egg cells enter the uterus through the oviduct. Other vertebrates of both sexes possess a cloaca for the release of sperm or egg cells. Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. Sexual reproduction also occurs in some unicellular eukaryotes. Sexual reproduction does not occur in pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vestigiality
Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on comparison with homology (biology), homologous features in related species. The emergence of vestigiality occurs by normal evolutionary processes, typically by loss of function of a feature that is no longer subject to Directional selection, positive Evolutionary pressure, selection pressures when it loses its value in a changing environment. The feature may be Negative selection (natural selection), selected against more urgently when its function becomes definitively harmful, but if the lack of the feature provides no advantage, and its presence provides no disadvantage, the feature may not be phased out by natural selection and persist across species. Examples of vestigial structures (also called degenerate, atrophied, or rudimentary orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Appendage
An appendage (or outgrowth) is an external body part or natural prolongation that protrudes from an organism's body such as an arm or a leg. Protrusions from single-celled bacteria and archaea are known as cell-surface appendages or surface appendages. In many kinds of eukaryotic cells, the protrusions are known as membrane protrusions or cell appendages (examples include microvilli and cilia). Types in animals In arthropods, an appendage refers to any of the homologous body parts that may extend from a body segment, including antennae, mouthparts (including mandibles, maxillae and maxillipeds), gills, locomotor legs ( pereiopods for walking, and pleopods for swimming), sexual organs ( gonopods), and parts of the tail (uropods). Typically, each body segment carries one pair of appendages. An appendage which is modified to assist in feeding is known as a maxilliped or gnathopod. In annelids lateral protrusions from the body are called parapodia. In echinoderms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thorax
The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the body, each in turn composed of multiple segments. The human thorax includes the thoracic cavity and the thoracic wall. It contains organs including the heart, lungs, and thymus gland, as well as muscles and various other internal structures. The chest may be affected by many diseases, of which the most common symptom is chest pain. Etymology The word thorax comes from the Greek θώραξ ''thṓrax'' " breastplate, cuirass, corslet" via . Humans Structure In humans and other hominids, the thorax is the chest region of the body between the neck and the abdomen, along with its internal organs and other contents. It is mostly protected and supported by the rib cage, spine, and shoulder girdle. Contents The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
