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Diploid Cell
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair—the form in which chromosomes naturally exist. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present (the "ploidy level"): monoploid (1 set), diploid (2 sets), triploid (3 sets), tetraploid (4 sets), pentaploid (5 sets), hexaploid (6 sets), heptaploid or septaploid (7 sets), etc. The generic term polyploid is often used to describe cells with three or more sets of chromosomes. Virtually all sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary widely between different organisms, between different tissues within the same organism, and at different stages in an org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiosis
Meiosis () is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells. It involves two rounds of division that ultimately result in four cells, each with only one copy of each chromosome (haploid). Additionally, prior to the division, genetic material from the paternal and maternal copies of each chromosome is crossed over, creating new combinations of code on each chromosome. Later on, during fertilisation, the haploid cells produced by meiosis from a male and a female will fuse to create a zygote, a cell with two copies of each chromosome. Errors in meiosis resulting in aneuploidy (an abnormal number of chromosomes) are the leading known cause of miscarriage and the most frequent genetic cause of developmental disabilities. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells, each with half the number of chromosomes as the original parent cell. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Difference Of Haploid And Diploid Gene Regulation In Mendelian Genetics
Difference commonly refers to: * Difference (philosophy), the set of properties by which items are distinguished * Difference (mathematics), the result of a subtraction Difference, The Difference, Differences or Differently may also refer to: Music * ''Difference'' (album), by Dreamtale, 2005 * ''The Difference'' (album), Pendleton, 2008 * "The Difference" (The Wallflowers song), 1997 * "Differences" (song), by Ginuwine, 2001 * ''Differently'' (album), by Cassie Davis, 2009 ** "Differently" (song), by Cassie Davis, 2009 * "Difference", a song by Benjamin Clementine from the 2022 album ''And I Have Been'' * "The Difference", a song by Matchbox Twenty from the 2002 album ''More Than You Think You Are'' * "The Difference", a song by Westlife from the 2009 album ''Where We Are'' * "The Difference", a song by Nick Jonas from the 2016 album '' Last Year Was Complicated'' * "The Difference", a song by Meek Mill featuring Quavo, from the 2016 mixtape '' DC4'' * "The Difference", a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Henry Lang
William Henry Lang FRS FRSE FLS (12 May 1874–29 August 1960) was a British botanist and served as Barker professor of cryptogamic botany at the University of Manchester. He was also a specialist in paleobotany. Life The son of Thomas Bilsland Lang, a medical practitioner, and his wife Emily Smith, he was born in Groombridge in Sussex on 12 May 1874. Lang was educated at Dennistoun Public School in Glasgow before being accepted into the University of Glasgow, where he graduated with a Bsc (Hons) in botany and zoology in 1894. He qualified for medicine in 1895 but never became a practising doctor; thanks to his own enthusiasm and the encouragement of his teacher Frederick Orpen Bower he instead became a professional botanist. His first research was on the structure of ferns, something Bower was apparently an authority on, and Lang soon followed him in that regard. He moved to study at the Jodrell Laboratory on a Robert Donaldson scholarship in 1895, where he focused on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germ Plasm
Germ plasm () is a biological concept developed in the 19th century by the German biologist August Weismann. It states that heritable information is transmitted only by germ cells in the gonads (ovaries and testes), not by somatic cells. The related idea that information cannot pass from somatic cells to the germ line, contrary to Lamarckism, is called the Weismann barrier. To some extent this theory anticipated the development of modern genetics. History The term ''Keimplasma'' (germ plasm) was first used by the German biologist, August Weismann (1834–1914), and described in his 1892 book ''Das Keimplasma: eine Theorie der Vererbung'' (The Germ Plasm: a theory of inheritance). His theory states that multicellular organisms consist of germ cells that contain and transmit heritable information, and somatic cells which carry out ordinary bodily functions. In the germ plasm theory, inheritance in a multicellular organism only takes place by means of the germ cells: the gamete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
August Weismann
August Friedrich Leopold Weismann (; 17 January 18345 November 1914) was a German evolutionary biology, evolutionary biologist. Fellow German Ernst Mayr ranked him as the second most notable evolutionary theorist of the 19th century, after Charles Darwin. Weismann became the Director of the Zoological Institute and the first Professor of Zoology at University of Freiburg, Freiburg. His main contribution involved germ plasm theory, at one time also known as Weismannism,Romanes, George John. ''An examination of Weismannism''. The Open court publishing company in Chicago 189/ref> according to which inheritance (in a multicellular animal) only takes place by means of the germ cells—the gametes such as egg cells and sperm cells. Other cells of the body—somatic cells—do not function as agents of heredity. The effect is one-way: germ cells produce somatic cells and are not affected by anything the somatic cells learn or therefore any ability an individual acquires during its life. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eduard Strasburger
Eduard Adolf Strasburger (1 February 1844 – 18 May 1912) was a Polish- German professor and one of the most famous botanists of the 19th century. He discovered mitosis in plants. Life Eduard Strasburger was born in Warsaw, Congress Poland, the son of Anna Karoline (von Schütz) and Eduard Gottlieb Strasburger (1803–1874)."Eduard STRASBURGER ward 1844 in Warschau als ältester Sohn des Kaufmannes EDUARD GOTTLIEB STRASBURGER und seiner Frau ANNA KAROLINE geb. V. SCHÜTZ geboren. Die Vorfahren beider Eltern waren seinerzeit mit den sächsischen Königen nach Polen gegangen.Nachrufe. Eduard Strasburger. Von Gr. Karsten zobodat.atKlaus Oskar Leyde: Strasburger. In: Deutsches Geschlechterbuch Band 207 (56. Allgemeiner Band), C. A. Starke Verlag, Limburg 1998, S. 227–242. In 1870, he married Alexandra Julia ("Alexandrine") Wertheim (1847–1902), they had two children: Anna (1870–1942) and Julius (1871–1934). Strasburger studied biological sciences in Paris, Bonn and Je ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greek Language
Greek (, ; , ) is an Indo-European languages, Indo-European language, constituting an independent Hellenic languages, Hellenic branch within the Indo-European language family. It is native to Greece, Cyprus, Italy (in Calabria and Salento), southern Albania, and other regions of the Balkans, Caucasus, the Black Sea coast, Asia Minor, and the Eastern Mediterranean. It has the list of languages by first written accounts, longest documented history of any Indo-European language, spanning at least 3,400 years of written records. Its writing system is the Greek alphabet, which has been used for approximately 2,800 years; previously, Greek was recorded in writing systems such as Linear B and the Cypriot syllabary. The Greek language holds a very important place in the history of the Western world. Beginning with the epics of Homer, ancient Greek literature includes many works of lasting importance in the European canon. Greek is also the language in which many of the foundational texts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuple
In mathematics, a tuple is a finite sequence or ''ordered list'' of numbers or, more generally, mathematical objects, which are called the ''elements'' of the tuple. An -tuple is a tuple of elements, where is a non-negative integer. There is only one 0-tuple, called the ''empty tuple''. A 1-tuple and a 2-tuple are commonly called a singleton and an ordered pair, respectively. The term ''"infinite tuple"'' is occasionally used for ''"infinite sequences"''. Tuples are usually written by listing the elements within parentheses "" and separated by commas; for example, denotes a 5-tuple. Other types of brackets are sometimes used, although they may have a different meaning. An -tuple can be formally defined as the image of a function that has the set of the first natural numbers as its domain. Tuples may be also defined from ordered pairs by a recurrence starting from an ordered pair; indeed, an -tuple can be identified with the ordered pair of its first elements and its t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Back-formation
Back-formation is the process or result of creating a neologism, new word via Morphology (linguistics), morphology, typically by removing or substituting actual or supposed affixes from a lexical item, in a way that expands the number of lexemes associated with the corresponding root (linguistics), root word.Crystal, David. ''A Dictionary of Linguistics and Phonetics, Sixth Edition'', Blackwell Publishers, 2008. James Murray (lexicographer), James Murray coined the term ''back-formation'' in 1889. (''Oxford English Dictionary, Oxford English Dictionary Online'' preserves its first use of 'back-formation' from 1889 in the definition of ''to burgle''; from ''burglar''.) For example, the noun ''resurrection'' was borrowed from Latin, and the verb ''resurrect'' was then back-formed hundreds of years later from it by removing the ''-ion'' suffix. This segmentation of ''resurrection'' into ''resurrect'' + ''ion'' was possible because English language, English had examples of Latin words ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turner Syndrome
Turner syndrome (TS), commonly known as 45,X, or 45,X0,Also written as 45,XO. is a chromosomal disorder in which cells of females have only one X chromosome instead of two, or are partially missing an X chromosome (sex chromosome monosomy) leading to the complete or partial deletion of the pseudoautosomal regions (PAR1, PAR2) in the affected X chromosome. Typically, people have two sex chromosomes (XX for females or XY for males). The chromosomal abnormality is often present in just some cells, in which case it is known as Turner syndrome with mosaicism. 45,X0 with mosaicism can occur in males or females, but Turner syndrome without mosaicism only occurs in females. Signs and symptoms vary among those affected but often include additional skin folds on the neck, arched palate, low-set ears, low hairline at the nape of the neck, short stature, and lymphedema of the hands and feet. Those affected do not normally develop menstrual periods or mammary glands without hormone trea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euploidy And Aneuploidy
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair—the form in which chromosomes naturally exist. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present (the "ploidy level"): monoploid (1 set), diploid (2 sets), triploid (3 sets), tetraploid (4 sets), pentaploid (5 sets), hexaploid (6 sets), heptaploid or septaploid (7 sets), etc. The generic term polyploid is often used to describe cells with three or more sets of chromosomes. Virtually all sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary widely between different organisms, between different tissues within the same organism, and at different stages in an o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
