distinguish miosis mitosis myositis For the figure of speech meiosis figure of speech mergefrom Origin and function of meiosis date November 2010 discuss Talk Meiosis Merge discussion Image Meiosis Overview.svg right thumb 300px Events involving meiosis, showing chromosomal crossover Meiosis pronounced ... . In animal s, meiosis produces gamete s like sperm and Ovum egg cells , while in other organisms like fungi it generates spore s. Meiosis begins with one Ploidy diploid cell containing Ploidy ..., which enables them to Adaptation adapt during the course of evolution . Before meiosis, the cell ... called sister chromatids and attached at the centromere region. In the beginning of meiosis, the maternal ... daughter cells, a second round of cell division occurs. There meiosis ends as the two sister chromatids ... fertilization , for example when a sperm enters an egg cell, two gamete cells produced by meiosis ... that make up the new offsping s genome . Meiosis uses many of the same mechanisms as mitosis ... identical daughter cells. In all plants, and in many protists, meiosis results in the formation of spores ..., like Bdelloid rotifers , have lost the ability to carry out meiosis and have acquired the ability to reproduce by parthenogenesis . Meiosis does not occur in archaea or bacteria , which reproduce via asexual processes such as binary fission . History Meiosis was discovered and described for the first ... worms eggs. The significance of meiosis for reproduction and inheritance, however, was described ... crossover in Drosophila melanogaster meiosis and provided the first genetic evidence that genes are transmitted on chromosomes. The term meiosis was coined by J.B Farmer and J.B Moore in 1905. Evolution Meiosis is thought to have appeared 1.4 billion years ago. The only supergroup of eukaryotes which does not have meiosis in all organisms is excavata . The other five major supergroups, opisthokonts , amoebozoa , rhizaria , archaeplastida and chromalveolates all seem to have genes for meiosis ... more details
mergeto Meiosis date November 2010 discuss Talk Meiosis Merge discussion Eukaryotes are organisms with a true ... is achieving an understanding of the origin and function of meiosis. Meiosis is a key stage of the sexual cycle in eukaryotes. Meiosis is the stage of the sexual cycle in which a diploid cell, ordinarily .... Meiosis is ubiquitous among eukaryotes. It occurs in single celled organisms such as yeast, as well ... to understand 1 how meiosis arose in single celled eukaryotes, and 2 the function of meiosis. Origin of Meiosis There are two conflicting theories on how meiosis arose. One is that meiosis evolved from bacterial sex called transformation as bacteria evolved into eukaryotes. The other is that meiosis arose from mitosis. Theory that meiosis evolved from bacterial sex transformation In prokaryotic sex ... transformation. One theory on how meiosis arose is that it evolved from transformation. ref name Bernstein ... during meiosis journal BioScience year 2010 volume 60 issue 7 pages 498 505 doi 10.1525 bio.2010.60.7.5 .... Transformation, like meiosis, is a complex process requiring the function of numerous gene products ... two functionally similar counterparts that act in eukaryotic meiosis, Rad51 and Dmc1. Support for the theory that meiosis arose from bacterial transformation comes from the increasing evidence that early diverging lineages of eukaryotes have the core genes for meiosis. This implies that the precursor to meiosis was already present in the bacterial ancestor of eukaryotes. For instance the common intestinal ... shown that G. intestinalis contains within its genome a core set of genes that function in meiosis, including five genes that function only in meiosis. ref name Ramesh 2005 cite journal author Ramesh ... and an early eukaryotic origin of meiosis journal Curr. Biol. volume 15 issue 2 pages 185 91 year ... was recently found to undergo a specialized, sex like process involving meiosis gene homologs ..., suggest that a primitive form of meiosis, was present in the common ancestor of all eukaryotes ... more details
In rhetoric , meiosis is a euphemism euphemistic figure of speech that intentionally understatement understates something or implies that it is lesser in significance or size than it really is. Meiosis is the opposite of auxesis figure of speech auxesis , and also sometimes used as a synonym for litotes ref Encarta World English Dictionary 1999 ref ref The Times English Dictionary 2000 ref ref name oed OED 1st edition ref The term is derived from the Greek to make smaller , to diminish . Examples The Troubles as a name for decades of violence in Northern Ireland. The Recent Unpleasantness, used in the southern United States as an idiom to refer to the American Civil War and its aftermath Similarly, slavery in the United States was often known as the Peculiar Institution . Intolerable meiosis comments a character in William Golding s To the Ends of the Earth Fire Down Below Fire Down Below as their ship encounters an iceberg after another character comments, We are privileged. How many people have seen anything like this? . The entirety of the Black Knight Monty Python Black Knight scene from Monty Python and the Holy Grail . See also Figure of speech Paradiastole Euphemism Minimisation psychology Minimisation References cite web last Burton first Gideon O. title Meiosis work Silva Rhetoricae url http rhetoric.byu.edu figures M meiosis.htm accessdate 2006 12 24 references Category Rhetorical techniques bs Mejoza figura hr Mejoza figura mk ja no Meiosis uk ... more details
Unreferenced stub auto yes date December 2009 Orphan date December 2009 Monopolin is a protein complex required for the segregation of homologous centromere s to opposite poles of a dividing cell during Meiosis anaphase I of meiosis . category Proteins category Molecular biology Protein stub ... more details
Unreferenced auto yes date December 2009 Interkinesis or interphase II is a period of rest that cell biology cells enter during meiosis . It is the abbreviated interphase that occurs between meiosis I and II. No DNA replication occurs during this stage of meiosis. Many plants skip telophase I and interkinesis, going immediately into prophase II. Each chromosome still consists of two chromatid s. Category Cellular processes Genetics stub pl Interkineza ... more details
wiktionary tetrad Tetrad may refer to MeiosisMeiosis I Tetrad chromosomal formation , a chromosomal formation in meiosis Tetrad general relativity , a mathematical frame of reference in general relativity Tetrad genetics , the four spores of a yeast Tetrad Greek philosophy , the first number formed by the addition and multiplication of equals Tetrad index notation , a concept in differential geometry Tetrad music , a set of four notes Tetrad unit of area , an area 2km x 2km square Tetromino , a shape composed of four squares Tetrad of media effects , a pedagogical tool disambig ... more details
Nondisjunction not coming apart is the failure of chromosome pairs to separate properly during meiosis . This could arise from a failure of homologous chromosomes to separate in meiosis I , or the failure of sister chromatids to separate during meiosis II or mitosis . The result of this error is a cell with an imbalance of chromosomes. Such a cell is said to be aneuploid . Loss of a single chromosome 2n 1 , in which the daughter cell s with the defect will have one chromosome missing from one of its pairs, is referred to as a monosomy . Gaining a single chromosome, in which the daughter cell s with the defect will have one chromosome in addition to its pairs is referred to as a trisomy . The following diagram shows the two possible types of nondisjunction in meiosis class wikitable 2n n 1 n 1 n 1 n 1 n 1 n 1 2n n n n n n 1 n 1 Schematic of nondisjunction in meiosis I. Duplicated chromosomes in diploid cell 2n . All gametes are affected by nondisjunction in meiosis I. Two gametes have a single extra chromosome two gametes are missing a single chromosome. Schematic of nondisjunction in meiosis II. Duplicated chromosomes in diploid cell 2n . Half of the gametes are affected by nondisjunction in meiosis II. One gamete has a single extra chromosome one gamete is missing a single chromosome. n denotes a cell with a single copy of each chromosome haploid cell 2n denotes a cell with two copies of each chromosome diploid cell External links http faculty.clintoncc.suny.edu faculty Michael.Gregory files Bio 20101 Bio 20101 20Laboratory Human 20Genetics 201 Nondisjunction.htm Human Genetics http ghr.nlm.nih.gov ghr glossary nondisjunction Genetics Home Reference Chromosomal abnormalities References Snustad, D.P., Simmons, M.J. 2006 . Principles of Genetics 4th ed. . Hoboken John Wiley & Sons, Inc. genetics stub Category Genetics Category Wikipedia articles with ASCII art de Non Disjunction nl Non disjunctie pl Nondysjunkcja pt N o disjun o sv Nondisjunction ... more details
Unreferenced stub auto yes date December 2009 A meiocyte is a Cell biology cell which is an immediate precursor to a gamete . It is so named because meiosis occurs in the cell. A meiocyte goes through meiosis 2 divisions to form a tetrad genetics tetrad . This tetrad consists of 4 genetically different cells that have half the genetic information of the meiocyte from which it came. Reproductive physiology Category Cell cycle Cell biology stub ... more details
orphan date October 2010 Synizesis refers to a phenomenon sometimes observed in one of the subphases of meiosis . This phenomenon, sometimes referred to as a synizetic knot , and contrasted with the chromosome bouquet more typically observed, is characterized by the localization of the meiotic chromosomes in a tight clump on one side of the nucleus. The term synizesis seems to have been coined by McClung in 1905. See also Meiosis References reflist The chromosome complex of orthopteran spermatocytes. CE McClung The Biological Bulletin, 1905 Category Cellular processes biology stub ... more details
Cleanup date January 2008 Unreferenced date January 2008 A bivalent , sometimes referred to as a tetrad , is a pair of associated homologous chromosome s held together by a complex after chromosome replication. During meiosis the Prophase I stage of Meiosis I , the process of synapsis occurs in which bivalents are formed. Each replicated chromosome is composed of two chromatid s. Bivalents are formed as two homologous chromosomes get close enough for a protein complex synaptonemal complex to hold them together. It is at this stage that genetic recombination can occur. Crossing over may occur between these bivalents during meiosis leading to chiasma formation. Category Chromosomes Category Cell cycle de Bivalent Meiose pl Biwalent genetics stub ... more details
orphan date September 2010 Meiomitosis is an aberrant cellular division pathway through which cancer daughter cells following mitosis also inherit partially expressed meiosis meiotic machinery. Of note, meiosis is cellular division pathway in germ cells that promotes the recombination of large expanses of chromosomal DNA, potentially similar in size to those lost or gained in cancers. In meiosis, homologous chromosomes are held together by cohesions, and after resolution of chiasma the recombination crossover points with the other chromosome pair , the homologous chromosomes are segregated together. In normal mitosis, there are no chiasma and sister chromatids are directly separated. References 1. Grichnik JM 2008 Melanoma, Nevogenesis, and Stem Cell Biology. J Invest Dermatol 128 2365 2380. Category Cell cycle cell biology stub ... more details
250px Gametic meiosis In gametic meiosis , instead of immediately dividing meiotically to produce ... of more unicellular diploid cells. Cells from the diploid individuals then undergo meiosis to produce ... meiosis is also called a diplontic life cycle . Diplonts are Animal s Some brown algae Some fungi , e.g. brewer s yeast Haplodiplontic life cycle File Sporic meiosis.png thumb 250px Sporic meiosis In sporic meiosis also commonly known as intermediary meiosis , the zygote divides mitotically to produce a multicellular diploid sporophyte . The sporophyte creates spores via meiosis which also then divide ... more details
Unreferenced date August 2009 A gametid is a kind of germ cell that results from the meiosis of a gametocyte . Male gametids are spermatid s, while female gametids are ootid s. The development of a gametids is called gametidogenesis . Cell biology stub Category Germ cells es Gameto th ... more details
Unreferenced stub auto yes date December 2009 Image Gray1150.png thumb 350px right Cross section of the epithelium of a seminiferous tubule showing various stages of spermatocyte development Image Gray7.png thumb 350px right Scheme showing analogies in the process of maturation of the ovum and the development of the spermatids young spermatozoa . Spermatidogenesis is the creation of spermatid s from spermatocytes secondary spermatocytes during spermatogenesis . Secondary spermatocytes produced earlier rapidly enter meiosis meiosis II and divide to produce haploid spermatid s. The brevity of this stage means that secondary spermatocytes are rarely seen in histological preparations. Male reproductive system Category Male reproductive system Cell biology stub ru ... more details
immature ova spend most of their lifetime, more specifically in prophase I of meiosis. The halt is called ... by meiosis I in oogenesis. ref http www.biochem.northwestern.edu holmgren Glossary Definitions Def ... chromatids 2N . The secondary oocyte continues the second stage of meiosismeiosis II , and the daughter ... more details
Orphan date February 2009 Mergeto Meiosis date December 2008 Meiome is the term used in functional genomics for meiotic transcriptome. ref http www.horticulture.umn.edu Changbin Chen.html ref ref http www.agwine.adelaide.edu.au plant pbg gm ref Meiosis is a key feature for all sexual reproducing eukaryotes in which homologous chromosome pairing, synapse and recombination are unique. Since meiosis in most organisms occur in a short time period, study of meiotic transcript profiling is extremely hard due to the chanllenge of isolation of meiotic cells. There are a list of groups studying on meiotic transcriptome using high throughput techniques such as microarray and sequencing technologies. Meiome is the way to study transcript profiling using mRNA isolated from enriched meiotic cells meiocytes . Currently there are two major approaches to understand the RNA accumulation in meiocytes 1 RNA seq and 2 Microarray. The RNA seq tech is more powerful for whole transcriptome analysis, the available analyzers such as Illumina Genome Analyzer 2 and Roche 454 analyzer made this approach more powerful. References Reflist Category Cellular processes Category Molecular genetics ... more details
In rhetoric , auxesis is a form of hyperbole that intentionally overstates something or implies that it is greater in significance or size than it really is. Auxesis is the opposite of Meiosis figure of speech meiosis . ref Encarta World English Dictionary 1999 ref ref The Times English Dictionary 2000 ref ref name oed OED 1st edition ref Auxesis may also refer to a sequence of clause s with increasing force. In this sense, auxesis is comparable to, but not synonymous with Climax figure of speech climax . ref http rhetoric.byu.edu figures A auxesis.htm Gideon O. Burton, Brigham Young University Silva Rhetoricae ref Examples Referring to a scratch as a wound . References references See also Climax figure of speech Climax Figure of speech Paradiastole Euphemism Category Rhetorical techniques ja ... more details
Unreferenced stub auto yes date December 2009 Microsporangium is a sporangium that produces spores that give rise to male gametophyte s. Microsporangia are notable in spikemoss es, and a minority of fern s. In Gymnosperms and Angiosperms Flowering plants , the microsporangium produce the microsporocyte, also known as the microspore mother cell, which then creates four microspores through meiosis. The microspores divide to create pollen grains. The term is not used for Bryophytes . Category Plant anatomy Botany stub it Microsporangio mk ... more details
Infobox Disease Name Uniparental disomy Image Caption DiseasesDB ICD10 ICD10 Q 99 8 q 90 ICD9 ICDO OMIM MedlinePlus eMedicineSubj eMedicineTopic MeshID D024182 Uniparental disomy UPD occurs when a person receives two copies of a chromosome , or part of a chromosome, from one parent and no copies from the other parent. ref name pmid10797485 cite journal author Robinson WP title Mechanisms leading to uniparental disomy and their clinical consequences journal Bioessays volume 22 issue 5 pages 452 9 year 2000 month May pmid 10797485 doi 10.1002 SICI 1521 1878 200005 22 5 452 AID BIES7 3.0.CO 2 K ref . UPD could involve isodisomy meiosis II error or heterodisomy meiosis I error ref cite book title Human Molecular Genetics 3 publisher Garland Science isbn 0 8153 4183 0 pages 58 ref . Pathophysiology UPD can occur as a random event during the formation of Ovum egg or sperm cells or may happen in early fetus fetal development. It can also occur during trisomic rescue . When the child receives two different homologous chromosomes inherited from both grandparents from one parent, this is called an heterodisomic UPD. Heterodisomy heterozygous indicates a Meiosis Meiosis I meiosis I error. When the child receives two identical replica copies of a single homolog of a chromosome , this is called an isodisomic UPD. Isodisomy homozygous indicates either a Meiosis Meiosis II meiosis II or postzygotic chromosomal duplication . Phenotype Most occurrences of UPD result in no phenotypical anomalies. However, if the UPD causing event happens during meiosis II, the genotype may include identical copies of the uniparental chromosome isodisomy , leading to the manifestation of rare recessive disorders. UPD should be suspected in an individual manifesting a recessive disorder, where only one parent is a Genetic carrier carrier . Uniparental Biological inheritance inheritance of Imprinting genetics imprinted genes can also result in phenotypical anomalies. Few imprinted genes have been identi ... more details
primary Oocyte diploid Ootidogenesis meiosis 1 Folliculogenesis Dictyate in prophase I for up to 50 years secondary Oocyte haploid Ootidogenesis meiosis 2 Halted in metaphase II until fertilization Ovum haploid Oogonium Oocytogenesis Primary Oocyte Meiosis I First Polar Body Discarded afterward Secondary oocyte Meiosis II Secondary Polar Body Discarded afterward Ovum The Creation of Oogonia The creation ... by the process of meiosis . In fact, a primary oocyte is, by its biological definition, a cell whose primary function is to divide by the process of meiosis. ref http www.biochem.northwestern.edu ... then continue to develop, although only a few do so every menstrual cycle . Meiosis I Meiosis ..., synapsis occurs and tetrad s form, enabling Chromosomal crossover to occur. As a result of meiosis I , the primary oocyte has now developed into the secondary oocyte and the first polar body . Meiosis II Immediately after meiosis I, the haploid secondary oocyte initiates meiosis II . However .... When meiosis II has completed, an ootid and another polar body have now been created. Folliculogenesis ... bodies disintegrate at the end of Meiosis II, leaving only the ootid, which then eventually undergoes ... sets of chromosomes that have resulted as a consequence of meiosis. In vitro maturation Main In vitro ... that generally only one product of female meiosis survives to maturity. In plant s, oogenesis occurs .... In ascaris , the oocyte does not even begin meiosis until the sperm touches it, in contrast to mammals, where meiosis is completed in the estrus cycle. See also Oogonium Archegonium Oocyte Spermatogenesis ... more details
for a successful meiosis, but the chiasma formation that takes place within synapsis has consequences ... Cell biology stub de Meiose Reduktionsteilung Meiose I es Sinapsis meiosis fr Synapsis pt ... more details
encoded by this gene is essential for meiotic homologous recombination. Genetic recombination in meiosis ... homolog, meiosis specific homologous recombination yeast url http www.ncbi.nlm.nih.gov sites entrez ... A, West S C year 1999 month Nov. title The meiosis specific recombinase hDmc1 forms ring structures ... pmc 148005 cite journal author Masson JY, Davies AA, Hajibagheri N, et al. title The meiosis specific ... related proteins at meiosis in the mouse are compatible with models that can resolve the early ... K, et al. title p53 Protein interacts specifically with the meiosis specific mammalian RecA like protein DMC1 in meiosis. journal Carcinogenesis volume 25 issue 6 pages 889 93 year 2004 pmid 14764457 ... DV, Golub EI, Stasiak AZ, et al. title Activation of human meiosis specific recombinase Dmc1 by Ca2 ... more details
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