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Kleptogenesis
In biology, a klepton (abbr. kl.) and synklepton (abbr sk.) is a species that requires input from another biological taxon (normally from a species which is closely related to the kleptonic species) to complete its reproductive cycle. Specific types of kleptons are ''zygokleptons'', which reproduce by zygogenesis; ''gynokleptons'' which reproduce by gynogenesis, and ''tychokleptons'', which reproduce by a combination of both systems. Kleptogenic reproduction results in three potential outcomes. A unisexual female may simply activate cell division in the egg through the presence of a male's sperm without incorporating any of his genetic material—this results in the production of clonal offspring. The female may also incorporate the male's sperm into her egg, but can do so without excising any of her genetic material. This results in increased ploidy levels that range from triploid to pentaploid in wild individuals. Finally, the female also has the option of replacing some of her ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parthenogenesis In Amphibians
Parthenogenesis is a form of reproduction where eggs develop without fertilization, resulting in unisexual species. This phenomenon is closely related with reproductive modes such as hybridogenesis, where fertilization occurs, but the paternal DNA is not passed on. Among amphibians, it is seen in numerous frog and salamander species, but has not been recorded in caecilians. Artificial parthenogenesis Haploid parthenogenesis has been achieved experimentally in amphibians, through approaches that could be considered artificial gynogenesis. Oscar Hertwig first achieved artificial parthenogenesis in frogs in 1911, using eggs fertilized by irradiated sperm. The radiation destroyed the DNA within the sperm, but nearly normal embryos were still produced. Gunther Hertwig repeated this experiment in 1924, using crosses between different frogs. A cross between a toad, '' Amietophrynus regularis'', and a frog, '' Rana fusca'', would not produce a viable embryo, but fertilization of a t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ambystoma Laterale
The blue-spotted salamander (''Ambystoma laterale'') is a mole salamander native to the Great Lakes region, Great Lakes states and northeastern United States, and parts of Ontario and Quebec in Canada. Their range is known to extend to James Bay to the north, and southeastern Manitoba to the west. Description Blue-spotted salamanders are between in length, of which the tail comprises 40%. Their skin is bluish-black, with characteristic blue and white flecks on its back, and bluish-white spots on the sides of its body and tail. They have elongated bodies. The Cloaca, vent is typically black, which contrasts with the paler belly. Larvae that have transformed may have yellow splotches; these turn blue once the individual becomes terrestrial. Occasionally, a Melanism, melanistic individual may be found in the wild. They have long toes: four on the front feet and five on the hind feet. Typically, specimens will have 12–14 costal grooves. Males tend to be smaller than females, thou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triploid
Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains one or more chromosomes and comes from each of two parents, resulting in pairs of homologous chromosomes between sets. 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 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 life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis, the sporophyte generation is diploid and produces spores by me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentaploid
Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei ( eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains one or more chromosomes and comes from each of two parents, resulting in pairs of homologous chromosomes between sets. 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 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 life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis, the sporophyte generation is diploid and produces spores by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hybridization In Green Frogs
Hybridization (or hybridisation) may refer to: *Hybridization (biology), the process of combining different varieties of organisms to create a hybrid *Orbital hybridization, in chemistry, the mixing of atomic orbitals into new hybrid orbitals *Nucleic acid hybridization, the process of joining two complementary strands of nucleic acids - RNA, DNA or oligonucleotides *In evolutionary algorithms, the merging two or more optimization techniques into a single algorithm **Memetic algorithm, a common template for hybridization *In linguistics, the process of one variety blending with another variety *The alteration of a vehicle into a hybrid electric vehicle *In globalization theory, the ongoing blending of cultures *Hybridization in political election campaign communication, the combining of campaign techniques developed in different countries *In paleoanthropology, the hypothesis of Neanderthal and human hybridization See also *Hybrid (other) Hybrid may refer to: Science * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelophylax Perezi
The Perez's frog, also known as Iberian waterfrog, Iberian green frog, or Coruna frog (''Pelophylax perezi'') is a species of frog in the family Ranidae. It is native to southern France, Portugal, Spain, and has been introduced to the Canary and Balearic Islands, Madeira, the United Kingdom, and the Azores. In the Iberian Peninsula it is widespread and common. Its natural habitats are temperate forests, temperate shrubland, Mediterranean-type shrubby vegetation, rivers, intermittent rivers, swamps, freshwater lakes, intermittent freshwater lakes, freshwater marshes, intermittent freshwater marshes, sandy shores, arable land, and urban areas. It is not considered threatened by the IUCN. See also * Hybridogenesis in water frogs The fertile hybrids of European water frogs (genus ''Pelophylax'') reproduce by hybridogenesis ( hemiclonally). This means that during gametogenesis, they discard the genome of one of the parental species and produce gametes of the other parenta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelophylax Bergeri
The Italian pool frog (''Pelophylax bergeri'') is a species of frog in the family Ranidae. Found on the mainland of Italy and the Mediterranean islands of Sicily, Elba, Corsica and Sardinia, its natural habitats are rivers, swamps, freshwater lakes and freshwater marshes. It is not considered threatened by the IUCN. Description The Italian pool frog grows to a snout-to-vent length of about and has a pointed snout and triangular-shaped head. The tongue is notched and it has vomerine teeth in the roof of its mouth. The skin is smooth and not warty. The colour is variable and depends on the animal's location, but is usually some shade of green with black spots, but may be reddish-brown or grey. There is a pale stripe running along the centre of the back. The underparts are greyish-white marked with dark blotches and the hind legs have dark stripes. Males have a pair of external vocal sacs on either side of the mouth which are only visible when the animal is calling. The voice is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poecilia Formosa
''Poecilia'' is a genus of fishes in the family Poeciliidae of the order Cyprinodontiformes. These livebearers are native to fresh, brackish and salt water in the Americas, and some species in the genus are euryhaline. A few have adapted to living in waters that contain high levels of toxic hydrogen sulfide ()Palacios, Arias-Rodriguez, Plath, Eifert, Lerp, Lamboj, Voelker, & Tobler (2013). The Rediscovery of a Long Described Species Reveals Additional Complexity in Speciation Patterns of Poeciliid Fishes in Sulfide Springs.' PLoS ONE 8(8): e71069. and a population of '' P. mexicana'' lives in caves (other populations of this species are surface-living). Some common and widespread species are often kept as aquarium fish, while other have very small ranges and are seriously threatened. All species in ''Poecilia'' are called mollies except for the Endler's livebearer (''P. wingei'') and the well-known guppy (''P. reticulata'') which have a distinctly different body shape from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gynogenesis
Gynogenesis, a form of parthenogenesis, is a system of asexual reproduction that requires the presence of sperm without the actual contribution of its DNA for completion. The paternal DNA dissolves or is destroyed before it can fuse with the egg. The egg cell of the organism is able to develop, unfertilized, into an adult using only maternal genetic material. Gynogenesis is often termed "sperm parasitism" in reference to the somewhat pointless role of male gametes. Gynogenetic species, "gynogens" for short, are unisexual, meaning they must mate with males from a closely related bisexual species that normally reproduces sexually. Gynogenesis is a disadvantageous mating system for males, as they are unable to pass on their DNA. The question as to why this reproductive mode exists, given that it appears to combine the disadvantages of both asexual and sexual reproduction, remains unsolved in the field of evolutionary biology. The male equivalent to this process is Androgenesis where the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apomixis
In botany, apomixis is asexual reproduction without fertilization. Its etymology is Greek for "away from" + "mixing". This definition notably does not mention meiosis. Thus "normal asexual reproduction" of plants, such as propagation from cuttings or leaves, has never been considered to be apomixis, but replacement of the seed by a plantlet or replacement of the flower by bulbils were categorized as types of apomixis. Apomictically produced offspring are genetically identical to the parent plant. Some authors included all forms of asexual reproduction within apomixis, but that generalization of the term has since died out. In flowering plants, the term "apomixis" is commonly used in a restricted sense to mean agamospermy, i.e., clonal reproduction through seeds. Although agamospermy could theoretically occur in gymnosperms, it appears to be absent in that group. Apogamy is a related term that has had various meanings over time. In plants with independent gametophytes (notably ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelophylax Lessonae
The pool frog (''Pelophylax lessonae'') is a European frog in the family Ranidae. Its specific name (zoology), specific name was chosen by the Italian Herpetology, herpetologist Lorenzo Camerano in 1882, in order to honour his master Michele Lessona. Description The pool frog is a small frog which rarely grows to more than 8 cm long, although females can grow up to 9 cm. Males are typically around 5 cm long, while females are around 6–6.5 cm long. These frogs are brown or green, with dark blotches along their backs, a pair of ridges running from each eye and a cream or yellow stripe down the middle of the frog's back. The vocal sacs on the male are cream or even white. Distribution The pool frog is found across most of central Europe from the west coast of northern France to the Western part of Russia. There are also small populations of pool frogs in the United Kingdom, Spain, Sweden and Norway. Pool frogs were previously thought to be a non-native species in the UK, but s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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