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Trioecy
Trioecy , also spelled triecy, is a sexual system characterized by the coexistence of males, females, and hermaphrodites. It has been found in both plants and animals. Like androdioecy and gynodioecy, trioecy is a mixed mating systems. Terminology Trioecy is also called tridioecy and subdioecy . The term trioecy comes from the Neo-Latin word '' Trioecia'', a former order of trioecious plants. Evolution of trioecy Trioecy may be an unstable transient state associated with evolutionary transitioning from gynodioecy to dioecy. In brachiopod species, trioecy usually breaks into androdioecy or gynodioecy. Other studies show that trioecious populations originated from gonochoristic ancestors which were invaded by a mutant selfing hermaphrodite, creating a trioecious population. It has been suggested that chromosomal duplication plays an important part in the evolution of trioecy. But one study found that trioecy can be stable under nucleocytoplasmic sex determination. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual System
A sexual system is a distribution of male and female functions across organisms in a species. The terms reproductive system and mating system have also been used as synonyms. Sexual systems play a key role in genetic variation and reproductive success, and may also have led to the origin or extinction of certain species. In flowering plants and animals, sexual reproduction involves meiosis, an adaptive process for repairing damage in the germline DNA transmitted to progeny. The distinctions between different sexual systems is not always clear due to phenotypic plasticity. Interest in sexual systems goes back to Charles Darwin, who found that barnacles include some species that are androdioecious and some that are dioecious. Types of sexual systems Flowering plants may have dimorphic or monomorphic sexual systems. In monomorphic sexual systems, a combination of hermaphrodite, male, and/or female flowers may be present on the same plant. Monomorphic sexual systems inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermaphrodite
A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many taxonomic groups of animals, primarily invertebrates, are hermaphrodites, capable of producing viable gametes of both sexes. In the great majority of tunicates, mollusks, and earthworms, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which either partner can act as the female or male. Hermaphroditism is also found in some fish species, but is rare in other vertebrate groups. Most hermaphroditic species exhibit some degree of self-fertilization. The distribution of self-fertilization rates among animals is similar to that of plants, suggesting that similar pressures are operating to direct the evolution of selfing in animals and plants. A rough estimate of the number of hermaphroditic animal species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioecy
Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is biparental reproduction. Dioecy has costs, since only the female part of the population directly produces offspring. It is one method for excluding self-fertilization and promoting allogamy (outcrossing), and thus tends to reduce the expression of recessive deleterious mutations present in a population. Plants have several other methods of preventing self-fertilization including, for example, dichogamy, herkogamy, and self-incompatibility. In zoology In zoology, dioecy means that an animal is either male or female, in which case the synonym gonochory is more often used. Most animal species are gonochoric, almost all vertebrate species are gonochoric, and all bird and mammal species are gonochoric. Dioecy may also describe colonies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Androdioecy
Androdioecy is a reproductive system characterized by the coexistence of males and hermaphrodites. Androdioecy is rare in comparison with the other major reproductive systems: dioecy, gynodioecy and hermaphroditism. In animals, androdioecy has been considered a stepping stone in the transition from dioecy to hermaphroditism, and vice versa. Androdioecy, trioecy and gynodioecy are sometimes referred to as a mixed mating systems. Androdioecy is a dimorphic sexual system in plants comparable with gynodioecy and dioecy. Evolution of androdioecy The fitness requirements for androdioecy to arise and sustain itself are theoretically so improbable that it was long considered that such systems do not exist. Particularly, males and hermaphrodites have to have the same fitness, in other words produce the same number of offspring, in order to be maintained. However, males only have offspring by fertilizing eggs or ovules of hermaphrodites, while hermaphrodites have offspring both th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercurialis Annua
''Mercurialis annua'', annual mercury, is a species of flowering plant in the spurge family Euphorbiaceae. It is native to the Middle East and the Mediterranean region, where it grows on bare, sandy soils. Its seeds are dispersed by harvester ants, which remove an oily coating that delays germination. In recent centuries, annual mercury has spread to northern Europe and many other parts of the world as an agricultural and urban weed. It has been studied for its complex genetics and breeding system. The name is from the Roman god Mercury, due to its association with fertility. Description Annual mercury is an annual plant, annual herbaceous plant, herb which typically grows to about 30–50 cm (exceptionally, up to 1 m) tall, with an erect, branched stem that has two strong ridges along its length, changing sides at each node. The whole plant is more-or-less Glabrousness, glabrous and, when broken, it exudes a watery sap (not a white latex, as other Euphorbiaceae do). It is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonochorism
In biology, gonochorism is a sexual system where there are two Sex, sexes and each individual organism is either male or female. The term gonochorism is usually applied in animal species, the vast majority of which are gonochoric. Gonochorism contrasts with simultaneous hermaphroditism but it may be hard to tell if a species is gonochoric or Sequential hermaphroditism, sequentially hermaphroditic e.g. parrotfish, ''Patella ferruginea''. However, in gonochoric species individuals remain either male or female throughout their lives. Species that reproduce by Thelytokous, thelytokous parthenogenesis and do not have males can still be classified as gonochoric. Terminology The term is derived from Greek language, Greek ''gone'' 'generation' + ''chorizein'' 'to separate'. The term gonochorism originally came from German ''Gonochorismus''. Gonochorism is also referred to as unisexualism or gonochory. Evolution Gonochorism has Convergent evolution, evolved independently multiple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuchsia Procumbens
''Fuchsia procumbens'' is a prostrate shrub that is endemic to coastal areas of the North Island (New Zealand), North Island of New Zealand. Common names include creeping fuchsia, climbing fuchsia or trailing fuchsia. Description Vegetative characteristics Its stems are slender, creeping, and weakly woody. They can climb heights of close to 1 m on small shrubs.Godley, E. J., & Berry, P. E. (1995)"The biology and systematics of ''Fuchsia'' in the South Pacific."Annals of the Missouri Botanical Garden, 473-516. The circular, 7–12 mm big leaves, which are attached singly to the stem, have dentate leaf margins, as well as trichomes on the surface.''Fuchsia procumbens'' - The University of Auckland. (n.d.). Retrieved April 5, 2023, from https://www.nzplants.auckland.ac.nz/en/about/seed-plants-flowering/onagraceae/fuchsia-procumbens.html Generative characteristics The erect, radially symmetrical flowers with a yellow floral tube do not have any petals. Instead, it has four sep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coccoloba Cereifera
''Coccoloba cereifera'' is a rare species of flowering plant in the knotweed or buckwheat family Polygonaceae. The species is restricted to a single mountain, the Serra do Cipó, in southern Brazil. The species is notable for its expression of a trioecious sexual system A sexual system is a distribution of male and female functions across organisms in a species. The terms reproductive system and mating system have also been used as synonyms. Sexual systems play a key role in genetic variation and reproductive .... References cereifera Endemic flora of Brazil {{Polygonaceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gynodioecy
Gynodioecy is a rare breeding system that is found in certain flowering plant species in which female and hermaphroditic plants coexist within a population. Gynodioecy is the evolutionary intermediate between hermaphroditism (exhibiting both female and male parts) and dioecy (having two distinct morphs: male and female). Gynodioecy is sometimes considered a mixed mating system comparable with trioecy and androdioecy. It is also considered a dimorphic sexual system alongside dioecy and androdioecy. Gynodioecy occurs as a result of transmission of nuclear (nuclear male sterility) or, more commonly, extra-nuclear (e.g. cytoplasmic male sterility) mutated alleles, which prevents pollen production, while keeping the female reproductive parts intact; other members of the species population don't inherit the mutated alleles, thus remaining hermaphrodites. In some cases, a combination of both nuclear and extra-nuclear mechanisms is observed in determining the sterile phenotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleodorina Starrii
''Pleodorina starrii'' is a species of algae that resides in freshwater in Japan. The name ''starri'' is in honor of phycologist Richard C. Starr. Since 2006 it has provided molecular genetic evidence for an evolutionary link between sexes and mating types. It was later confirmed to be the first reportedly trioecious haploid species. Description ''Pleodorina starrii'' is a colonial organism. The colonies are spherical or ellipsoidal and consist of 32 or 64 biflagellate cells embedded in the periphery of a gelatinous matrix, thus forming a hollow sphere. Cells are differentiated into somatic and reproductive cells; in 32-celled colonies, 8–12 of the cells are somatic while in 64-celled colonies, 18–20 of the cells are somatic. Somatic cells are nearly spherical, up to 13 μm in diameter, having a cup-shaped chloroplast with a single pyrenoid. Two contractile vacuoles are present near the base of the flagella, as well as several others near the cell surface. Reproductive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachycereus Pringlei
''Pachycereus pringlei'' (also known as Mexican giant cardon or elephant cactus) is a species of large cactus native to northwestern Mexico, in the states of Baja California, Baja California Sur, and Sonora. It is commonly known as ''cardón'', a name derived from the Spanish word ''cardo'', meaning "thistle"; additionally, it is often referred to as sabueso (or “bloodhound”), which is possibly an early Spanish interpretation of the native Seri term for the plant, xaasj. Large stands of this cactus still exist, but many have been destroyed as land has been cleared for cultivation in Sonora. Climate change will likely impact the future distribution of numerous plant species, including ''Pachycereus pringlei,'' which can be attributed to alterations in precipitation and temperature. The cactus fruits were always an important food for the Seri people, in Sonora; the dried cactus columns themselves could be used for construction purposes, as well as for firewood.* A symbiotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buddleja Americana
''Buddleja americana'' is the most widespread of all the ''Buddleja'' species native to the Americas, its range extending south from Tamaulipas, Mexico, through Central America and much of the West Indies into South America, reaching eastward to Venezuela, westward as far as the Galapagos, and south to Bolivia. It occurs at elevations from sea level to 2500 m, in a variety of habitats, including cloud forest, mountain savanna, pine–oak forest, and rocky slopes near rivers. It also invades fields and roadsides.Norman, E. M. (2000). Buddlejaceae. ''Flora Neotropica 81'', New York Botanical Garden, USA The species was originally named and described by Linnaeus in 1753.Linnaeus, C. (1753). ''Sp. pl.'' 112. 1753. Description ''B. americana'' is a trioecious shrub, 2–5 m tall with light brown fissured bark. The young branches are sub quadrangular, and tomentose, bearing leaves which vary greatly in size, shape and indumentum. The inflorescences are 5–25 c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
