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Petr Ivanov
Piotr Pavlovich Ivanov (russian: Петр Павлович Иванов; 9 April 1878 – 15 February 1942) was a Soviet embryologist and a professor. He studied segmentation in annelids and arthropods and proposed the differentiation of two kinds of segments in segmented organisms and the developmental (or ontogenetic) idea of heteronomous metamery where several segments fuse to perform a common function. Life and work Ivanov was born in St. Petersburg where his father Pavel worked in the Volga-Kama bank. He graduated from the 1st classical gymnasium in 1896 and joined St. Petersburg University where he studied zoology under Vladimir Shevyakov. His research was on the regeneration of segments in the worm ''Lumbriculus variegatus ''Lumbriculus variegatus'', also known as the blackworm or California blackworm, is a species of worm inhabiting North America and Europe. It lives in shallow-water marshes, ponds, and swamps, feeding on microorganisms and organic material. The ... ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ivanov Petr Pavlovich
Ivanov, Ivanoff or Ivanow (masculine, bg, Иванов, russian: ИвановSometimes the stress is on Ива́нов in Bulgarian if it is a middle name, or in Russian as a rare variant of pronunciation), or Ivanova (feminine, bg, Иванова, russian: Иванова) is one of the most common surnames in Russia and Bulgaria. The surname is derived from the male given name Ivan (related to John) and literally means "Ivan's". People with the surname * Alena Ivanova, Kazakhstani volleyball player *Alexander Ivanov (other) – several people * Alexey Ivanov (other) – several people *Alina Ivanova (born 1969), Russian race walker and long-distance runner * Allen Ivanov, American mass shooter, responsible for the 2016 Mukilteo shooting * Almaz Ivanov (died 1669), Russian statesman *Alexander Andreyevich Ivanov (1806-1858), Russian painter *Anatoli Ivanov (musician) (1934–2012), Russian solo-timpanist and percussionist with the Saint Petersburg Philharmonic Or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamerism (biology)
In biology, metamerism is the phenomenon of having a linear series of body segments fundamentally similar in structure, though not all such structures are entirely alike in any single life form because some of them perform special functions. In animals, metameric segments are referred to as somites or metameres. In plants, they are referred to as metamers or, more concretely, phytomers. In animals In animals, zoologists define metamery as a mesodermal event resulting in serial repetition of unit subdivisions of ectoderm and mesoderm products. Endoderm is not involved in metamery. Segmentation is not the same concept as metamerism: segmentation can be confined only to ectodermally derived tissue, e.g., in the Cestoda tapeworms. Metamerism is far more important biologically since it results in metameres - also called somites - that play a critical role in advanced locomotion. One can divide metamerism into two main categories: * homonomous metamery is a strict serial succes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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