|
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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parthenogenesis
Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and development of embryos occur in a gamete (egg or sperm) without combining with another gamete (e.g., egg and sperm fusing). In animals, parthenogenesis means development of an embryo from an unfertilized Gametophyte, egg cell. In plants, parthenogenesis is a component process of apomixis. In algae, parthenogenesis can mean the development of an embryo from either an individual sperm or an individual egg. Parthenogenesis occurs naturally in some plants, algae, invertebrate animal species (including nematodes, some tardigrades, water fleas, some scorpions, aphids, some mites, some bees, some Phasmatodea and parasitic wasps) and a few vertebrates (such as some fish, amphibians, reptiles and birds). This type of reproduction has been induced artificially ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 parental species (containing a genome not recombined with the genome of the first parental species). The first parental genome is restored by fertilization of these gametes with gametes from the first species (sexual host). In all-hybrid populations of the edible frog ''Pelophylax'' kl. ''esculentus'', however, triploid hybrids provide this missing genome. Because half of the genome is transmitted to the next generation clonally (not excluded unrecombined intact genome), and only the other half sexually (recombined genome of the sexual host), the hybridogenesis is a hemiclonal mode of reproduction. For example, the edible frog ''Pelophylax'' kl. ''esculentus'' (mostly RL genome), which is a hybridogenetic hybrid of the marsh frog ''P. ridibund ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Klepton
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] |
Myrmecia Impaternata
''Myrmecia impaternata'' is a species of gynogenetic, female-only ant in the genus ''Myrmecia''. Described by Robert Taylor in 2015, the species is endemic to Australia and is common in Canberra and around Armidale. Observations of the species have been confirmed in Queensland. ''M. impaternata'' is a hybrid species, with its origin tracing back to ''Myrmecia banksi'' and ''Myrmecia pilosula Myrmecia can refer to: * ''Myrmecia'' (alga), genus of algae associated with lichens * ''Myrmecia'' (ant), genus of ants called bulldog ants * Myrmecia (skin), a kind of deep wart on the human hands or feet See also * '' Copromorpha myrmecias'' ...''. References Myrmeciinae Hymenoptera of Australia Insects described in 2015 Insects of Australia {{Myrmeciinae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blue-spotted Salamander
The blue-spotted salamander (''Ambystoma laterale'') is a mole salamander native to the 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 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 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, though they have longer, flattened tails. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mole Salamander
The mole salamanders (genus ''Ambystoma'') are a group of advanced salamanders endemic to North America. The group has become famous due to the presence of the axolotl (''A. mexicanum''), widely used in research due to its paedomorphosis, and the tiger salamander (''A. tigrinum, A. mavortium'') which is the official amphibian of many states, and often sold as a pet. General description Terrestrial mole salamanders are identified by having wide, protruding eyes, prominent costal grooves, and thick arms. Most have vivid patterning on dark backgrounds, with marks ranging from deep blue spots to large yellow bars depending on the species. Terrestrial adults spend most of their lives underground in burrows, either of their own making or abandoned by other animals. Some northern species may hibernate in these burrows throughout the winter. They live alone and feed on any available invertebrate. Adults spend little time in the water, only returning to the ponds of their birth to br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jefferson Salamander
The Jefferson salamander (''Ambystoma jeffersonianum'') is a mole salamander native to the northeastern United States, southern and central Ontario, and southwestern Quebec. It was named after Jefferson College in Pennsylvania. It is typically dark gray, brown, or black on its dorsal surface, but a lighter shade on its anterior. Some individuals may also have silver or blue specks on their sides; the area around the vent is usually gray. These salamanders are slender, with a wide nose and distinctive long toes, and range in size from . Like other mole salamanders, the Jefferson salamander burrows; they have well-developed lungs suited for this purpose. Nocturnal by nature, they can be spotted by day during the mating season. Breeding occurs in early spring, after the snow in the area has melted. Reproduction Eggs are laid in small agglomerations attached to submerged twigs or other natural support at the pond's edge. Clutches can contain between 5 and 60 eggs, averaging about 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplodiploidy
Haplodiploidy is a sex-determination system in which males develop from unfertilized eggs and are haploid, and females develop from fertilized eggs and are diploid. Haplodiploidy is sometimes called arrhenotoky. Haplodiploidy determines the sex in all members of the insect orders Hymenoptera (bees, ants, and wasps) and Thysanoptera ('thrips'). The system also occurs sporadically in some spider mites, Hemiptera, Coleoptera (bark beetles), and rotifers. In this system, sex is determined by the number of sets of chromosomes an individual receives. An offspring formed from the union of a sperm and an egg develops as a female, and an unfertilized egg develops as a male. This means that the males have half the number of chromosomes that a female has, and are haploid. The haplodiploid sex-determination system has a number of peculiarities. For example, a male has no father and cannot have sons, but he has a grandfather and can have grandsons. Additionally, if a eusocial-insect colo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silvery Salamander
The silvery salamander (''Ambystoma platineum'') is a hybrid species of mole salamander from the United States of America and Canada. It is usually between 5.5 – 7.75 in (12 – 19.9 cm) long and is slender with many small silvery-blue spots on its back and sides. It is brownish grey and the area around its vent is grey. This unisexual ''Ambystoma'' hybrid species, has been grouped with other unisexual ambystomatids that takes genetic material from Jefferson salamander (''A. jeffersonianum''), streamside salamander (''A. barbouri''), small-mouthed salamander (''A. texanum''), tiger salamander (''A. tigrinum'') and the blue-spotted salamander (''A. laterale''). "Species name designations for unisexual ''Ambystoma'' are no longer in use". Instead, unisexual ''Ambystoma'' are now considered distinct biotypes rather than species. Behaviour Lacking its own males, the LJJ biotype breeds with male blue-spotted or Jefferson salamanders from March to April. The males' sper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Androgenesis
Androgenesis occurs when a zygote is produced with only paternal nuclear genes. During standard sexual reproduction, one female and one male parent each produce haploid gametes(such as a sperm or egg cell, each containing only a single set of chromosomes), which recombine to create offspring with genetic material from both parents. However, in androgenesis, there is no recombination of maternal and paternal chromosomes, and only the paternal chromosomes are passed down to the offspring (the inverse of this is gynogenesis, where only the maternal chromosomes are inherited, which is more common than androgenesis). The offspring produced in androgenesis will still have maternally inherited mitochondria, as is the case with most sexually reproducing species. One of two things can occur to produce offspring with exclusively paternal genetic material: the maternal nuclear genome can be eliminated from the zygote, or the female can produce an egg with no nucleus, resulting in an embryo d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jack Jumper Ant
Jack may refer to: Places * Jack, Alabama, US, an unincorporated community * Jack, Missouri, US, an unincorporated community * Jack County, Texas, a county in Texas, USA People and fictional characters * Jack (given name), a male given name, including a list of people and fictional characters with the name * Jack (surname), including a list of people with the surname * Jack (Tekken), multiple fictional characters in the fighting game series ''Tekken'' * Jack the Ripper, an unidentified British serial killer active in 1888 * Wolfman Jack (1938–1995), a stage name of American disk jockey Robert Weston Smith * New Jack, a stage name of Jerome Young (1963-2021), an American professional wrestler * Spring-heeled Jack, a creature in Victorian-era English folklore Animals and plants Fish *Carangidae generally, including: **Almaco jack **Amberjack **Bar jack **Black jack (fish) **Crevalle jack **Giant trevally or ronin jack **Jack mackerel **Leather jack **Yellow jack *Coho salmon, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_Danube_delta.jpg "Click for more on -> Hybridogenesis In Water Frogs")
