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Hermaphrodite
In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrates) do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which either partner can act as the female or male. For example, the great majority of tunicata, tunicates, pulmonate molluscs, opisthobranch, earthworms, and slugs are hermaphrodites. Hermaphroditism is also found in some fish species and to a lesser degree in other vertebrates. Most plants are also hermaphrodites. Animal species having different sexes, male and female, are called Gonochorism, gonochoric, which is the opposite of hermaphrodite. There are also species where hermaphrodites exist alongside males (called androdioecy) or alongside females (called gynodioecy), or all three exist in the same species ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intersex
Intersex people are individuals born with any of several sex characteristics including chromosome patterns, gonads, or genitals that, according to the Office of the United Nations High Commissioner for Human Rights, "do not fit typical binary notions of male or female bodies". Sex assignment at birth usually aligns with a child's anatomical sex and phenotype. The number of births with ambiguous genitals is in the range of 1:2000–1:4500 (0.022%–0.05%). Other conditions involve atypical chromosomes, gonads, or hormones. Some persons may be assigned and raised as a girl or boy but then identify with another gender later in life, while most continue to identify with their assigned sex. The number of births where the baby is intersex has been reported differently depending on who reports and which definition of intersex is used. Anne Fausto-Sterling and her co-authors suggest that the prevalence of "nondimorphic sexual development" might be as high as 1.7%. A study publish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intersex Society Of North America
The Intersex Society of North America (ISNA) was a non-profit advocacy group founded in 1993 by Cheryl Chase to end shame, secrecy, and unwanted genital surgeries.Matthews, Karen (Oct 22, 2000). Debate Grows Over Using Surgery on Infants with Ambiguous Genitals. ''Los Angeles Times''Murrell, Nancy (October 28, 1998). Intersex group raises questions about genital surgery. ''Miami Herald''Hackford-Peer, Kim (2005). Cheryl Chase Founds the Intersex Society of North America. in ''GLBT History, 1993–2004''; 2005, p28-30, 2p Other notable members included Morgan Holmes, Max Beck, Howard (Tiger) Devore, Esther Morris Leidolf and Alice Dreger. The organization closed in June 2008,Staff report (June 28, 2008)Farewell message. via ISNA.org and has been succeeded by a number of health, civil and human rights organizations including interACT. Advocacy Physical integrity and bodily autonomy ISNA stated that newborn intersex genitals should not be operated on, unless they need to be in or ... [...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 is sometimes referred to as a mixed breeding system with trioecy and gynodioecy. It is a dimorphic sexual system in plants alongside 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 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 through fertilizing eggs or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexes
Sex is the trait that determines whether a sexually reproducing animal or plant produces male or female gametes. Male plants and animals produce smaller mobile gametes (spermatozoa, sperm, pollen), while females produce larger ones (ova, often called egg cells). Organisms that produce both types of gametes are called hermaphrodites. During sexual reproduction, male and female gametes fuse to form zygotes, which develop into offspring that inherit traits from each parent. Males and females of a species may have physical similarities (sexual monomorphism) or differences (sexual dimorphism) that reflect various reproductive pressures on the respective sexes. Mate choice and sexual selection can accelerate the evolution of physical differences between the sexes. The terms ''male'' and ''female'' typically do not apply in sexually undifferentiated species in which the individuals are isomorphic (look the same) and the gametes are isogamous (indistinguishable in size and shape), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioecy
Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is biparental reproduction. Dioecy has costs, since only about half 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. Dioecy is a dimorphic sexual system, alongside gynodioecy and androdioecy. In zoology In zoology, dioecious species may be opposed to hermaphroditic species, meaning that an individual is either male or female, in which case the synonym gonochory is more often used. Most animal species are dioecious (gon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trioecy
Trioecy, or subdioecy, is a rare sexual system characterized by the coexistence of males, females, and hermaphrodites. It has been found in both plants and animals. Trioecy is sometimes referred to as a mixed mating system alongside androdioecy and gynodioecy. Evolution of trioecy Many speculate trioecy is a transient state and is often associated with evolutionary transitioning from gynodioecy to dioecy. 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 is an important part in the evolution of trioecy. Evolutionary stability Trioecy is usually viewed as evolutionarily unstable, but its exact stability is unclear. Like in brachiopod species trioecy usually breaks into androdioecy or gynodioecy. But one study found that trioecy can be stable under nucleocytoplasmic sex determination. Another theoretical ... [...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 breeding system alongside trioecy and androdioecy. It is also considered a dimorphic sexual system alongside dioecy and androdioecy. Gynodioecy occurs as a result of a genetic mutation that inhibits a hermaphroditic plant from producing pollen, while keeping the female reproductive parts intact. Gynodioecy is extremely rare, with fewer than 1% of angiosperm species exhibiting the breeding system. Some notable taxa that exhibit a gynodioecious mating system include ''Beta vulgaris'' (wild beet), ''Lobelia siphilitica'', ''Silene'', and Lamiaceae. Evolution Gynodioecy is often referred to as the evolutionary intermed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonochorism
In biology, gonochorism is a sexual system where there are only 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 Hermaphrodite, simultaneous hermaphroditism but it may be hard to tell if a species is gonochoric or 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 time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reproductive Organs
A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. The reproductive organs together constitute the reproductive system. In animals, the testis in the male, and the ovary in the female, are called the ''primary sex organs''. All others are called ''secondary sex organs'', divided between the external sex organs—the genitals or external genitalia, visible at birth in both sexes—and the internal sex organs. Mosses, ferns, and some similar plants have gametangia for reproductive organs, which are part of the gametophyte. The flowers of flowering plants produce pollen and egg cells, but the sex organs themselves are inside the gametophytes within the pollen and the ovule. Coniferous plants likewise produce their sexually reproductive structures within the gametophytes contained within the cones and pollen. The cones and pollen are not themselves sexual organs. Terminology The ''primary sex organs'' are the gonads, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snails Mating
A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gastropoda that have a coiled shell that is large enough for the animal to retract completely into. When the word "snail" is used in this most general sense, it includes not just land snails but also numerous species of sea snails and freshwater snails. Gastropods that naturally lack a shell, or have only an internal shell, are mostly called ''slugs'', and land snails that have only a very small shell (that they cannot retract into) are often called ''semi-slugs''. Snails have considerable human relevance, including as food items, as pests, and as vectors of disease, and their shells are used as decorative objects and are incorporated into jewelry. The snail has also had some cultural significance, tending to be associated with lethargy. The snai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes (the archaea and bacteria). By one definition, plants form the clade Viridiplantae (Latin name for "green plants") which is sister of the Glaucophyta, and consists of the green algae and Embryophyta (land plants). The latter includes the flowering plants, conifers and other gymnosperms, ferns and their allies, hornworts, liverworts, and mosses. Most plants are multicellular organisms. Green plants obtain most of their energy from sunlight via photosynthesis by primary chloroplasts that are derived from endosymbiosis with cyanobacteria. Their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic or mycotrophic and have lost the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Social Stigma
Social stigma is the disapproval of, or discrimination against, an individual or group based on perceived characteristics that serve to distinguish them from other members of a society. Social stigmas are commonly related to culture, gender, race, socioeconomic class, age, sexual orientation, body image, physical disability, intelligence or lack thereof, and health. Some stigma may be obvious, while others are known as concealable stigmas that must be revealed through disclosure. Stigma can also be against oneself, stemming from negatively viewed personal attributes in a way that can result in a "spoiled identity" (i.e., self-stigma). Description Stigma (plural stigmas or ''stigmata'') is a Greek word that in its origins referred to a type of marking or the tattoo that was cut or burned into the skin of people with criminal records, slaves, or those seen as traitors in order to visibly identify them as supposedly blemished or morally polluted persons. These individuals were to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
