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Xenopus
''Xenopus'' () (Gk., ξενος, ''xenos'' = strange, πους, ''pous'' = foot, commonly known as the clawed frog) is a genus of highly aquatic frogs native to sub-Saharan Africa. Twenty species are currently described within it. The two best-known species of this genus are '' Xenopus laevis'' and '' Xenopus tropicalis'', which are commonly studied as model organisms for developmental biology, cell biology, toxicology, neuroscience and for modelling human disease and birth defects. The genus is also known for its polyploidy, with some species having up to 12 sets of chromosomes. Characteristics ''Xenopus laevis'' is a rather inactive creature. It is incredibly hardy and can live up to 15 years. At times the ponds that ''Xenopus laevis'' is found in dry up, compelling it, in the dry season, to burrow into the mud, leaving a tunnel for air. It may lie dormant for up to a year. If the pond dries up in the rainy season, ''Xenopus laevis'' may migrate long di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenopus Laevis Female With Egg Batch And Xenopus Tropicalis Male - Journal
''Xenopus'' () (Gk., ξενος, ''xenos'' = strange, πους, ''pous'' = foot, commonly known as the clawed frog) is a genus of highly aquatic frogs native to sub-Saharan Africa. Twenty species are currently described within it. The two best-known species of this genus are ''Xenopus laevis'' and ''Xenopus tropicalis'', which are commonly studied as model organisms for developmental biology, cell biology, toxicology, neuroscience and for modelling human disease and birth defects. The genus is also known for its polyploidy, with some species having up to 12 sets of chromosomes. Characteristics ''Xenopus laevis'' is a rather inactive creature. It is incredibly hardy and can live up to 15 years. At times the ponds that ''Xenopus laevis'' is found in dry up, compelling it, in the dry season, to burrow into the mud, leaving a tunnel for air. It may lie dormant for up to a year. If the pond dries up in the rainy season, ''Xenopus laevis'' may migrate long distanc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenopus Laevis
The African clawed frog (''Xenopus laevis''), also known as simply xenopus, African clawed toad, African claw-toed frog or the ''platanna'') is a species of African aquatic frog of the family Pipidae. Its name is derived from the short black claws on its feet. The word ''Xenopus'' means 'strange foot' and ''laevis'' means 'smooth'. The species is found throughout much of Sub-Saharan Africa (Nigeria and Sudan to South Africa), and in isolated, introduced populations in North America, South America, Europe, and Asia. All species of the family Pipidae are tongueless, toothless and completely aquatic. They use their hands to shove food in their mouths and down their throats and a hyobranchial pump to draw or suck things in their mouth. Pipidae have powerful legs for swimming and lunging after food. They also use the claws on their feet to tear pieces of large food. They have no external eardrums, but instead subcutaneous cartilaginous disks that serve the same function. They use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenopus Tropicalis
The western clawed frog (''Xenopus tropicalis'') is a species of frog in the family Pipidae, also known as tropical clawed frog. It is the only species in the genus ''Xenopus'' to have a diploid genome. Its genome has been sequenced, making it a significant model organism for genetics that complements the related species ''Xenopus laevis'' (the African clawed frog), a widely used vertebrate model for developmental biology. ''X. tropicalis'' also has a number of advantages over ''X. laevis'' in research, such as a much shorter generation time (<5 months), smaller size ( body length), and a larger number of eggs per . It is found in , |
Frogs
A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough skin texture due to wart-like parotoid glands tend to be called toads, but the distinction between frogs and toads is informal and purely cosmetic, not from taxonomy or evolutionary history. Frogs are widely distributed, ranging from the tropics to subarctic regions, but the greatest concentration of species diversity is in tropical rainforest and associated wetlands. They account for around 88% of extant amphibian species, and are one of the five most diverse vertebrate orders. The oldest fossil "proto-frog" ''Triadobatrachus'' is known from the Early Triassic of Madagascar (250million years ago), but molecular clock dating suggests their divergence from other amphibians may extend further back to the Permian, 265million years ago. Adult frogs have a st ... [...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] |
Polyploid
Polyploidy is a condition in which the biological cell, cells of an organism have more than two paired sets of (Homologous chromosome, homologous) chromosomes. Most species whose cells have Cell nucleus, nuclei (eukaryotes) are diploid, meaning they have two complete sets of chromosomes, one from each of two parents; each set contains the same number of chromosomes, and the chromosomes are joined in pairs of homologous chromosomes. However, some organisms are polyploid. Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes (eggs and sperm) by meiosis. A Ploidy, monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals, plants and multicellular algae have Biological life cycle, life cycles with two alternation of generations, alternating multicellular generations. The gamet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haptoglobin
Haptoglobin (abbreviated as Hp) is the protein that in humans is encoded by the ''HP'' gene. In blood plasma, haptoglobin binds with high affinity to ''free'' hemoglobin released from erythrocytes, and thereby inhibits its deleterious oxidative activity. Compared to Hp, hemopexin binds to ''free'' heme. The haptoglobin-hemoglobin complex will then be removed by the reticuloendothelial system (mostly the spleen). In clinical settings, the haptoglobin assay is used to screen for and monitor intravascular hemolytic anemia. In intravascular hemolysis, free hemoglobin will be released into circulation and hence haptoglobin will bind the hemoglobin. This causes a decline in haptoglobin levels. The protein was discovered as a "plasma substance" in 1938 by French biochemists Max-Fernand Jayle and Michel Polonovski. Function Hemoglobin that has been released into the blood plasma by damaged red blood cells has harmful effects. The ''HP'' gene encodes a preproprotein that is proc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Claw
A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or Arthropod leg, tarsus for gripping a surface as they walk. The pincers of crabs, lobsters and scorpions, more formally known as their chelae, are sometimes called claws. A true claw is made of a hard protein called keratin. Claws are used to catch and hold prey in carnivorous mammals such as cats and dogs, but may also be used for such purposes as digging, climbing trees, self-defense and Personal grooming, grooming, in those and other species. Similar appendages that are flat and do not come to a sharp point are called nail (anatomy), nails instead. Claw-like projections that do not form at the end of digits but spring from other parts of the foot are properly named Spur (zoology), spurs. Tetrapods In tetrapods, claws are made of keratin and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Line
The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial cells, known as hair cells, which respond to displacement caused by motion and transduce these signals into electrical impulses via excitatory synapses. Lateral lines play an important role in schooling behavior, predation, and orientation. Early in the evolution of fish, some of the sensory organs of the lateral line were modified to function as the electroreceptors called ampullae of Lorenzini. The lateral line system is ancient and basal to the vertebrate clade, as it is found in fishes that diverged over 400 million years ago. Function The lateral line system allows the detection of movement, vibration, and pressure gradients in the water surrounding an animal. It plays an essential role in orientation, predation, and fish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drought
A drought is a period of drier-than-normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, and O. Zolina, 2021Water Cycle Changes. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1055–1210, doi:10.1017/9781009157896.010. A drought can last for days, months or years. Drought often has large impacts on the ecosystems and agriculture of affected regions, and causes harm to the local economy. Annua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake
A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from the ocean, although they may be connected with the ocean by rivers. Lakes, as with other bodies of water, are part of the water cycle, the processes by which water moves around the Earth. Most lakes are fresh water and account for almost all the world's surface freshwater, but some are salt lakes with salinities even higher than that of seawater. Lakes vary significantly in surface area and volume of water. Lakes are typically larger and deeper than ponds, which are also water-filled basins on land, although there are no official definitions or scientific criteria distinguishing the two. Lakes are also distinct from lagoons, which are generally shallow tidal pools dammed by sandbars or other material at coastal regions of ocean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River
A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it runs out of water, or only flow during certain seasons. Rivers are regulated by the water cycle, the processes by which water moves around the Earth. Water first enters rivers through precipitation, whether from rainfall, the Runoff (hydrology), runoff of water down a slope, the melting of glaciers or snow, or seepage from aquifers beneath the surface of the Earth. Rivers flow in channeled watercourses and merge in confluences to form drainage basins, or catchments, areas where surface water eventually flows to a common outlet. Rivers have a great effect on the landscape around them. They may regularly overflow their Bank (geography), banks and flood the surrounding area, spreading nutrients to the surrounding area. Sedime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
