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Bradynema Rigidum
''Bradynema rigidum'' is a parasitic species of nematode in the Allantonematidae family. The species has been classified as androdioecious. The parasite will live freely in its host; groupings of 2–3 to up to twenty may occur together. In this species it was found that blastomeres in the 4 cell stage might be in 2 possible arrangements. The species was originally discovered by Philipp Franz von Siebold in the 19th century. Otto zur Strassen received a doctorate in 1892 for writing his dissertation about the nematode. The larva development was first described by Wülker. In this species male larva develop into adults after 8 days, while the females develop into adults after 7 or 10 days. All adults are hermaphrodites. It has been suggested that males develop ovaries The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philipp Franz Von Siebold
Philipp Franz Balthasar von Siebold (17 February 1796 – 18 October 1866) was a German physician, botanist and traveler. He achieved prominence by his studies of Japanese flora (plants), flora and fauna (animals), fauna and the introduction of Western medicine in Japan. He was the father of the first female Japanese doctor educated in Western medicine, Kusumoto Ine. Career Early life Born into a family of doctors and professors of medicine in Würzburg (then in the Bishopric of Würzburg, later part of Bavaria), Siebold initially studied medicine at the University of Würzburg from November 1815, where he became a member of the German Student Corps, Corps Moenania Würzburg. One of his professors was Franz Xaver Heller (1775–1840), author of the ' ("Flora of the Grand Duchy of Würzburg", 1810–1811). Ignaz Döllinger (1770–1841), his professor of anatomy and physiology, however, most influenced him. Döllinger was one of the first professors to understand and tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasitism
Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of life. The entomologist E. O. Wilson has characterised parasites as "predators that eat prey in units of less than one". Parasites include single-celled protozoans such as the agents of malaria, sleeping sickness, and amoebic dysentery; animals such as hookworms, lice, mosquitoes, and vampire bats; fungi such as Armillaria mellea, honey fungus and the agents of ringworm; and plants such as mistletoe, dodder, and the Orobanchaceae, broomrapes. There are six major parasitic Behavioral ecology#Evolutionarily stable strategy, strategies of exploitation of animal hosts, namely parasitic castration, directly transmitted parasitism (by contact), wikt:trophic, trophicallytransmitted parasitism (by being eaten), Disease vector, vector-transmitted paras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allantonematidae
Allantonematidae is a family of insect-parasitic nematodes from the order Tylenchida. Allantonematid nematodes infect a variety of insects including beetles, butterflies, flies, thrips, ants, and more. For instance, the nematode ''Howardula aoronymphium'' parasitizes mushroom-feeding fruit flies, '' Formicitylenchus oregonensis'' parasitizes carpenter ants, and ''Metaparasitylenchus hypothenemi'' parasitizes a pest of coffee beans, the coffee berry borer. Allantonematid nematodes infect insect larvae by piercing through the cuticle, after which they reside in the insect blood. There they develop through multiple juvenile stages before being shed out the anus or reproductive tracts. Mating typically occurs external to the insect host, after which mated female nematodes infect new hosts. Systematics There are 2 subfamilies of Allantonematids that contain about 150 species in at least 16 genera. These include: *Subfamily ** ** ** ** ** ** ** ** ** ** ** * Subfamily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Androdioecious
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] |
Blastomere
In biology, a blastomere is a type of cell produced by cell division (cleavage) of the zygote after fertilization; blastomeres are an essential part of blastula formation, and blastocyst formation in mammals. Human blastomere characteristics In humans, blastomere formation begins immediately following fertilization and continues through the first week of embryonic development. About 90 minutes after fertilization, the zygote divides into two cells. The two-cell blastomere state, present after the zygote first divides, is considered the earliest mitotic product of the fertilized oocyte. These mitotic divisions continue and result in a grouping of cells called blastomeres. During this process, the total size of the embryo does not increase, so each division results in smaller and smaller cells. When the zygote contains 16 to 32 blastomeres it is referred to as a morula. These are the preliminary stages in the embryo beginning to form. Once this begins, microtubules within the mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto Zur Strassen
Otto Karl Ladislaus zur Strassen (9 May 1869, in Berlin – 21 April 1961, in Oberstedten) was a German zoologist. An advocate of Darwinism, his primary focus was concerned with morphology (biology), biological morphology and developmental mechanics. Otto was the son of sculptor Melchior Anton and his wife Cecilia. He studied natural sciences at the Universities of University of Leipzig, Leipzig and University of Freiburg, Freiburg, obtaining his doctorate in 1892 at Leipzig with a dissertation on ''Bradynema rigidum''. After graduation, he furthered his education in Naples and in Russia. In 1901 he became an associate professor of specialized zoology at Leipzig, later working as a full professor of zoology at the University of Frankfurt am Main (1914–1935). In 1922/23 he served as university rector (academia), rector. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
