query: where does meiosis take place in humans and all other vertebrates

pos: Germ cell Germ cell A germ cell is any biological cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells originate in the primitive streak and migrate via the gut of an embryo to the developing gonads. There, they undergo meiosis, followed by cellular differentiation into mature gametes, either eggs or sperm. Unlike animals, plants do not have germ cells designated in early development. Instead, germ cells can arise from somatic cells in the adult (such as the floral meristem of flowering plants). Multicellular eukaryotes are made of two fundamental cell types. Germ

neg: Neoteny in humans significantly more defunct pseudogenes with functional homologs in the chimpanzee genome than vice versa. While the protein coding portion of the FOXP2 gene is identical to that in Neanderthals, there is one point mutation in the regulatory part thereof (modern humans having a T where Neanderthals and all nonhuman vertebrates have an A). The observation that the effect of that difference is that the modern human FOXP2 gene does not interact with RNA from other genes while all other vertebrate including Neanderthal varieties did agrees with the idea that modern human origins was marked by the elimination (not formation) of

neg: Leishmania that interact with each other to promote homologous recombinational repair. These proteins play a key role in meiosis. Thus, meiotic events provide the adaptive advantage of efficient recombinational repair of DNA damages even when they do not lead to outcrossing. Leishmania Leishmania is a genus of trypanosomes that are responsible for the disease leishmaniasis. They are spread by sandflies of the genus "Phlebotomus" in the Old World, and of the genus "Lutzomyia" in the New World. At least 93 sandfly species are proven or probable vectors worldwide. Their primary hosts are vertebrates; "Leishmania" commonly infects hyraxes, canids, rodents, and humans.

neg: Domestication of animals they take place over much longer time frames. The commensal pathway was traveled by vertebrates that fed on refuse around human habitats or by animals that preyed on other animals drawn to human camps. Those animals established a commensal relationship with humans in which the animals benefited but the humans received no harm but little benefit. Those animals that were most capable of taking advantage of the resources associated with human camps would have been the tamer, less aggressive individuals with shorter fight or flight distances. Later, these animals developed closer social or economic bonds with humans that led to

neg: Pain in fish have a functional opioid system which includes the presence of opioid receptors similar to those of mammals. All four of the main opioid receptor types (delta, kappa, mu, and NOP) are conserved in vertebrates, even in primitive jawless fishes (agnathastoma). The same analgesics and anaesthetics used in humans and other mammals, are often used for fish in veterinary medicine. These chemicals act on the nociceptive pathways, blocking signals to the brain where emotional responses to the signals are further processed by certain parts of the brain found in amniotes ("higher vertebrates"). Pre-treatment with morphine (an analgesic in humans and other

neg: Brain-to-body mass ratio ratio and complexity of behaviour is not perfect as other factors also influence intelligence, like the evolution of the recent cerebral cortex and different degrees of brain folding, which increase the surface of the cortex, which is positively correlated in humans to intelligence. The noted exception to this, of course, is swelling of the brain which, while resulting in greater surface area, does not alter the intelligence of those suffering from it. The relationship between brain weight and body weight of all living vertebrates follows two completely separate linear functions for cold-blooded and warm-blooded animals. Cold-blooded vertebrates have much smaller

neg: Origin and function of meiosis gametes and inhibit production of viable progeny. Even in multicellular eukaryotes, such as humans, oxidative stress is a problem for cell survival. In this case, oxidative stress is a byproduct of oxidative cellular respiration occurring during metabolism in all cells. In humans, on average, about 50 DNA double-strand breaks occur per cell in each cell generation. Meiosis, which facilitates recombinational repair between non-sister chromosomes, can efficiently repair these prevalent damages in the DNA passed on to germ cells, and consequently prevent loss of fertility in humans. Thus with the theory that meiosis arose from prokaryotic sex, recombinational repair is the

neg: Humans vs. Zombies safety of the players and non-players by not allowing realistic looking weaponry, weaponry which could hurt on impact, or dangerous behavior during gameplay. Since Humans vs. Zombies can last for days, rules establish "safe zones" where gameplay does not take place, and where players can stop participation in the game for a certain period. Safe zones are designated by the administrators in conjunction with University rules and/or other applicable rules. Safe zones include dorm rooms, bathrooms, dining halls, Academic buildings, Health centers and other such places. Safe zones vary by the rules set at each separate University. Some include every

neg: Fish intelligence extreme, the electrogenic elephantnose fish, an African freshwater fish, has one of the largest brain-to-body weight ratios of all known vertebrates (slightly higher than humans) and the highest brain-to-body oxygen consumption ratio of all known vertebrates (three times that for humans). Fish typically have quite small brains relative to body size compared with other vertebrates, typically one-fifteenth the brain mass of a similarly sized bird or mammal. However, some fish have relatively large brains, most notably mormyrids and sharks, which have brains about as massive relative to body weight as birds and marsupials. The cerebellum of cartilaginous and bony fishes

neg: Meiosis where they are again arrested just before ovulation. If these oocytes are fertilized by sperm, they will resume and complete meiosis. During folliculogenesis in humans, usually one follicle becomes dominant while the others undergo atresia. The process of meiosis in females occurs during oogenesis, and differs from the typical meiosis in that it features a long period of meiotic arrest known as the dictyate stage and lacks the assistance of centrosomes. In males, meiosis occurs during spermatogenesis in the seminiferous tubules of the testicles. Meiosis during spermatogenesis is specific to a type of cell called spermatocytes, which will later mature

neg: Cdc14 abnormally. The abnormality arises due to delay in dissembling of spindle during Anaphase I. However, the segregation of chromosomes continue and both the phases of meiotic segregations take place on prolonged meiosis I spindle. Cdc14 along with SPO12 and SLK19 play a critical role in ensuring that the two phases of chromosomal segregation take place consecutively during meiosis. Cdc14 is widely distributed, being found in most eukaryote kingdoms. However, it is not found in all species based on searches of sequenced genomes. One or more Cdc14 genes are found in alveolates, animals, fungi, trypanosomes, and lower plants. However, Cdc14 genes

neg: Other Minds: The Octopus, the Sea, and the Deep Origins of Consciousness underwater by Godfrey-Smith. He acknowledges the influence of Daniel Dennett's philosophy. Godfrey-Smith's premise in this book is the fact that intelligence has evolved separately in two groups of animals: in cephalopods like octopuses and cuttlefish, and in vertebrates like birds and humans. He notes that studying cephalopods is "probably the closest we will come to meeting an intelligent alien", but that "the minds of cephalopods are the most other of all." He describes many encounters with octopuses in the book, as he dives in the shallow waters off Australia, especially in a favoured place that he names "Octopolis" where many

neg: MUS81 MUS81 Crossover junction endonuclease MUS81 is an enzyme that in humans is encoded by the "MUS81" gene. In mammalian somatic cells, MUS81 and another structure specific DNA endonuclease, XPF (ERCC4), play overlapping and essential roles in completion of homologous recombination. The significant overlap in function between these enzymes is most likely related to processing joint molecules such as D-loops and nicked Holliday junctions. MUS81 is a component of a minor chromosomal crossover (CO) pathway in the meiosis of budding yeast, plants and vertebrates. However, in the protozoan "Tetrahymena thermophila", MUS81 appears to be part of an essential (if not the

neg: Animal welfare could potentially cause "pain, suffering, distress or lasting harm" to "protected animals". Initially, "protected animals" encompassed all living vertebrates other than humans, but, in 1993, an amendment added a single invertebrate species, the common octopus. Primates, cats, dogs, and horses have additional protection over other vertebrates under the Act. Revised legislation came into force in January 2013. This has been expanded to protect "...all living vertebrates, other than man, and any living cephalopod. Fish and amphibia are protected once they can feed independently and cephalopods at the point when they hatch. Embryonic and foetal forms of mammals, birds and reptiles

neg: RecLOH Rather, one homologous segment "writes over" the other. The mechanism is presumed to be different from RecLOH events in autosomal chromosomes, since the target is the very same chromosome instead of the homologous one. During the mutation one of these copies overwrites the other. Thus the differences between the two are lost. Because differences are lost, heterozygosity is lost. Recombination on the Y-chromosome does not only take place during meiosis, but virtually at every mitosis when the Y chromosome condenses, because it doesn't require pairing between chromosomes. Recombination frequency even exceeds the frame shift mutation frequency (slipped strand mispairing) of

neg: Amelanism is not, mammalian eyes appear blue. Melanin in the pigment epithelium is critical for visual acuity and contrast. Loss of melanogenesis function is linked to the gene that encodes tyrosinase. Certain alleles of this gene, "TYR", at the "Color" locus, cause oculocutaneous albinism type 1 in humans and the familiar red-eyed albino conditions in mice and other mammals. Other vertebrates, such as fishes, amphibians, reptiles and birds, produce a variety of non-melanin pigments. Disruption of melanin production does not affect the production of these pigments. Non-melanin pigments in other vertebrates are produced by cells called chromatophores. Within this categorization, xanthophores

neg: Parthenogenesis of anaphase II are joined together. The criterion for "sexuality" varies from all cases of restitutional meiosis, to those where the nuclei fuse or to only those where gametes are mature at the time of fusion. Those cases of automixis that are classified as sexual reproduction are compared to self-fertilization in their mechanism and consequences. The genetic composition of the offspring depends on what type of apomixis takes place. When endomitosis occurs before meiosis or when "central fusion" occurs (restitutional meiosis of anaphase I or the fusion of its products), the offspring get all to more than half of the

neg: Anatomical terms of location head from") the shoulders in the armadillo, the dog, the kangaroo, or any other terrestrial vertebrate, including the human. Likewise, while the belly is considered "anterior" to (in front of) the back in humans, this terminology fails for the flounder, the armadillo, and the dog. In veterinary terms, the belly would be "ventral" ("toward the abdomen") in all vertebrates. While it would be possible to introduce a system of axes that is completely consistent between humans and other vertebrates by having two separate pairs of axes, one used exclusively for the head (e.g., anterior/posterior and inferior/superior) and the other exclusively

neg: Cuvier–Geoffroy debate in science. To illustrate his points, Geoffroy used the example of the hyoid bone in vertebrates. He compared multiple animals with differing numbers of pieces making up the hyoid bone. In the cat with 9 hyoid pieces and humans with 5, Geoffroy made hypotheses for where the extra pieces had gone in humans, suggesting shifts to the ligaments and other bones of the jaw. Cuvier in response compared the hyoid bones across multiple species, where he saw different numbers of parts, different arrangements of the parts and in some, no hyoid at all. To Cuvier these differences suggested different functional

neg: Carboxypeptidase E within the C-terminal region of the protein. Carboxypeptidase E is found in all species of vertebrates that have been examined, and is also present in many other organisms that have been studied (nematode, sea slug). Carboxypeptidase E is not found in the fruit fly (Drosophila), and another enzyme (presumably carboxypeptidase D) fills in for carboxypeptidase E in this organism. In humans, CPE is encoded by the "CPE" gene. Carboxypeptidase E functions in the production of nearly all neuropeptides and peptide hormones. The enzyme acts as an exopeptidase to activate neuropeptides. It does that by cleaving off basic C-terminal amino acids,

neg: Vertebrate for the "Tree of Life Web Project" and Delsuc et al. The number of described vertebrate species are split evenly between tetrapods and fish. The following table lists the number of described extant species for each vertebrate class as estimated in the IUCN Red List of Threatened Species, 2014.3. The IUCN estimates that 1,305,075 extant invertebrate species have been described, which means that less than 5% of the described animal species in the world are vertebrates. The following databases maintain (more or less) up-to-date lists of vertebrate species: Nearly all vertebrates undergo sexual reproduction. They produce haploid gametes by meiosis.

neg: Fertilisation as in animals and plants. Meiosis results in a random segregation of the genes that each parent contributes. Each parent organism is usually identical save for a fraction of their genes; each gamete is therefore genetically unique. At fertilisation, parental chromosomes combine. In humans, (2²²)² = 17.6x10 chromosomally different zygotes are possible for the non-sex chromosomes, even assuming no chromosomal crossover. If crossover occurs once, then on average (4²²)² = 309x10 genetically different zygotes are possible for every couple, not considering that crossover events can take place at most points along each chromosome. The X and Y chromosomes undergo no

neg: BRCA1 in humans and mice in primordial follicles. Primordial follicles contain oocytes that are at an intermediate (prophase I) stage of meiosis. Meiosis is the general process in eukaryotic organisms by which germ cells are formed, and it is likely an adaptation for removing DNA damages, especially double-strand breaks, from germ line DNA. (Also see article Meiosis). Homologous recombinational repair employing BRCA1 is especially promoted during meiosis. It was found that expression of 4 key genes necessary for homologous recombinational repair of DNA double-strand breaks ("BRCA1, MRE11, RAD51" and "ATM") decline with age in the oocytes of humans and mice, leading

neg: Anatomical terms of location Anatomical terms of location Standard anatomical terms of location deal unambiguously with the anatomy of animals, including humans. All vertebrates (including humans) have the same basic body plan they are strictly bilaterally symmetrical in early embryonic stages and largely bilaterally symmetrical in adulthood. That is, they have mirror-image left and right halves if divided down the middle. For these reasons, the basic directional terms can be considered to be those used in vertebrates. By extension, the same terms are used for many other (invertebrate) organisms as well. While these terms are standardized within specific fields of biology, there are unavoidable,

neg: Relaxin family peptide hormones an example of vigorously diversified ligand-receptor systems in vertebrates. The number of peptides and their receptors is varied among vertebrates due to lineage specific gene loss and duplications For example, teleost fish have almost twice as many relaxin family peptide receptors compared to humans, which is attributable to the Fish-Specific Whole Genome Duplication and teleost-specific gene duplication. Relaxin family peptide hormones Relaxin family peptide hormones in humans are represented by 7 members: three relaxin-like (RLN) and four insulin-like (INSL) peptides. This subdivision into 2 classes (RLN and INSL) is based primarily on early findings, and does not reflect the evolutionary

neg: Linea alba (abdomen) a "six pack". Because it consists of mostly connective tissue, and does not contain any primary nerves or blood vessels, a "median incision" through the linea alba is a common surgical approach. Linea alba (abdomen) The white line () is a fibrous structure that runs down the midline of the abdomen in humans and other vertebrates. In humans linea alba runs from the xiphoid process to the pubic symphysis. The name means "white line" and the linea alba is indeed white, being composed mostly of collagen connective tissue. It is formed by the fusion of the aponeuroses of the abdominal

neg: Phonemic restoration effect to an optical illusion. It is believed that humans and other vertebrates have evolved the ability to complete acoustic signals that are critical but communicated under naturally noisy conditions. For humans, while it is not fully known at what point in the processing hierarchy does the phonemic restoration effect occurs, evidence points to dynamic restorative processes already occurring with basic modulations of sound set at natural articulation rates. People with mild and moderate hearing loss were tested for the effectiveness of phonemic restoration. Those with mild hearing loss performed at the same level of a normal listener. Those with moderate

neg: Brain neocerebellum) dedicated to supporting the cerebral cortex, which has no counterpart in other vertebrates. The brains of humans and other primates contain the same structures as the brains of other mammals, but are generally larger in proportion to body size. The encephalization quotient (EQ) is used to compare brain sizes across species. It takes into account the nonlinearity of the brain-to-body relationship. Humans have an average EQ in the 7-to-8 range, while most other primates have an EQ in the 2-to-3 range. Dolphins have values higher than those of primates other than humans, but nearly all other mammals have EQ

neg: REC8 REC8 Meiotic recombination protein REC8 homolog is a protein that in humans is encoded by the "REC8" gene. Rec8 is a meiosis-specific component of the cohesin complex that binds sister chromatids in preparation for the two divisions of meiosis. Rec8 is sequentially removed from sister chromatids. It is removed from the arms of chromosomes in the first division - separating homologous chromosomes from each other. However, Rec8 is maintained at centromeres so that sister chromatids are kept joined until anaphase of meiosis II, at which point removal of remaining cohesin leads to the separation of sister chromatids. This gene encodes

neg: Slit (protein) Slit (protein) Slit is a family of secreted extracellular matrix proteins which play an important signalling role in the neural development of most bilaterians (animals with bilateral symmetry). While lower animal species, including insects and nematode worms, possess a single Slit gene, humans, mice and other vertebrates possess three Slit homologs: Slit1, Slit2 and Slit3. Human "Slits" have been shown to be involved certain pathological conditions, such as cancer and inflammation. The ventral midline of the central nervous system is a key place where axons can either decide to cross and laterally project or stay on the same side of

neg: DMC1 (gene) the absence of Rad51 strand exchange activity, Dmc1 appears to be able to repair all meiotic DNA breaks, and this absence does not affect meiotic crossing over rates. DMC1 (gene) Meiotic recombination protein DMC1/LIM15 homolog is a protein that in humans is encoded by the "DMC1" gene. Meiotic recombination protein Dmc1 is a homolog of the bacterial strand exchange protein RecA. Dmc1 plays the central role in homologous recombination in meiosis by assembling at the sites of programmed DNA double strand breaks and carrying out a search for allelic DNA sequences located on homologous chromatids. The name "Dmc" stands for

neg: Meiosis (figure of speech) germ cells. However, it was not until a few years later that maiosis was renamed "meiosis" to better embody the Greek definition, "to reduce" or "diminish". Meiosis typically works to diminish the importance of something or someone in order to simultaneously heighten something else in its place. Such a comparative approach is necessary for the effectiveness of the device. An example of this device occurs in the New Testament where Paul belittles himself in order to emphasize the power of God: For I am the least of all the apostles and do not even deserve to be called an apostle,

neg: Chiasma (genetics) two pairs of sister chromatids, begins to split, the only points of contact are at the chiasmata. The chiasmata become visible during the diplotene stage of prophase I of meiosis, but the actual "crossing-overs" of genetic material are thought to occur during the previous pachytene stage. Sister chromatids also form chiasmata between each other (also known as a chi structure), but because their genetic material is identical, it does not cause any noticeable change in the resulting daughter cells. In humans, there seems to be one chiasma per chromosome arm, and in mammals, the number of chromosome arms is a

neg: Meiosis of preformed mRNA), regulating the ultimate meiotic stage-specific protein expression of genes during meiosis. Thus, both transcriptional and translational controls determine the broad restructuring of meiotic cells needed to carry out meiosis. Meiosis I segregates homologous chromosomes, which are joined as tetrads (2n, 4c), producing two haploid cells (n chromosomes, 23 in humans) which each contain chromatid pairs (1n, 2c). Because the ploidy is reduced from diploid to haploid, meiosis I is referred to as a "reductional division". Meiosis II is an "equational division" analogous to mitosis, in which the sister chromatids are segregated, creating four haploid daughter cells (1n,

neg: MAFK other erythroid-related genes. MAFK has been identified in many vertebrates, including humans. There are three functionally redundant sMaf proteins in vertebrates, MafF, MafG, and MafK. MafK has a bZIP structure that consists of a basic region for DNA binding and a leucine zipper structure for dimer formation. Similar to other sMafs, MafK lacks any canonical transcriptional activation domains. "MAFK" is broadly but differentially expressed in various tissues. "MAFK" expression was detected in all 16 tissues examined by the human BodyMap Project, but relatively abundant in adipose, lung and skeletal muscle tissues. Mouse "Mafk" is regulated by different GATA factors in

neg: Paleopolyploidy of the "Arabidopsis" and "Brassica" lineages, about to . Other examples include the sequenced eudicot genomes of apple, soybean, tomato, cotton, etc. Compared with plants, paleopolyploidy is much rarer in the animal kingdom. It has been identified mainly in amphibians and bony fishes. Although some studies suggested one or more common genome duplications are shared by all vertebrates (including humans), the evidence is not as strong as in the other cases because the duplications, if they exist, happened so long ago, and the matter is still under debate. The idea that vertebrates share a common whole genome duplication is known

neg: Mercedes Lackey bibliography series of novels is set on a world where both elves and dragons arrived from dimensional portals onto a world where humans were native. The dragons remained hidden and elves subjugated the humans. The story follows the exploits of a group of half-blooded humans attempting to fight the elves. Set in an earth where magic exists during the early 20th century, these stories follow magicians who control the powers of Air, Fire, Water, and Earth. These stories are based loosely—sometimes "very" loosely—on various fairy tales. Although these books all take place in the same "world" and all include the same

neg: PRDM9 by asymmetric double strand breaks. PRDM9 mediates the process of meiosis by directing the sites of homologous recombination. In humans and mice, recombination does not occur evenly throughout the genome but at particular sites along the chromosomes called recombination hotspots. Hotspots are regions of DNA about 1-2kb in length. There are approximately 30,000 to 50,000 hotspots within the human genome corresponding to one for every 50-100kb DNA on average. In humans, the average number of crossover recombination events per hotspot is one per 1,300 meioses, and the most extreme hotspot has a crossover frequency of one per 110 meioses. These

neg: Iris (anatomy) melanosomes in the iris of humans and other vertebrates are not mobile, and the degree of pigment dispersion cannot be reversed. Abnormal clumping of melanosomes does occur in disease and may lead to irreversible changes in iris color (see heterochromia, below). Colors other than brown or black are due to selective reflection and absorption from the other stromal components. Sometimes lipofuscin, a yellow "wear and tear" pigment, also enters into the visible eye color, especially in aged or diseased green eyes. The optical mechanisms by which the non-pigmented stromal components influence eye color are complex, and many erroneous statements exist

neg: Non-reproductive sexual behavior in animals necessities they will not survive. All vertebrates share similarities in body structure; they all have a skeleton, a nervous system, a circulatory system, a digestive system and excretory system. Similar to humans, non-human animals also have a sensory system. The sensory system is responsible for the basic five senses from touch to tasting. Most of the physiological and biochemical responses found in animals are found in humans. Neurophysiologists have not found any fundamental difference between the structure and function of neurons and synapse between humans and other animals. Recent studies using positron emission tomography (PET) and magnetic resonance imaging (MRI)

neg: Primate basal ganglia Primate basal ganglia The basal ganglia form a major brain system in all species of vertebrates, but in primates (including humans) there are special features that justify a separate consideration. As in other vertebrates, the primate basal ganglia can be divided into striatal, pallidal, nigral, and subthalamic components. In primates, however, there are two pallidal subdivisions called the external globus pallidus (GPe) and internal globus pallidus (GPi). Also in primates, the dorsal striatum is divided by a large tract called the internal capsule into two masses named the caudate nucleus and the putamen—in most other species no such division exists,

neg: PTPRT PTPRT Receptor-type tyrosine-protein phosphatase T is an enzyme that in humans is encoded by the "PTPRT" gene. PTPRT is also known as PTPrho, PTPρ and human accelerated region 9. The human accelerated regions are 49 regions of the human genome that are conserved among vertebrates, but in humans show significant distinction from other vertebrates. This region may, therefore, have played a key role in differentiating humans from apes. The protein encoded by this gene is a member of the protein tyrosine phosphatase (PTP) family. PTPs are known to be signaling molecules that regulate a variety of cellular processes including cell

neg: Meiosis attachment is referred to as a bipolar attachment. The physical basis of the independent assortment of chromosomes is the random orientation of each bivalent along the metaphase plate, with respect to the orientation of the other bivalents along the same equatorial line. The protein complex cohesin holds sister chromatids together from the time of their replication until anaphase. In mitosis, the force of kinetochore microtubules pulling in opposite directions creates tension. The cell senses this tension and does not progress with anaphase until all the chromosomes are properly bi-oriented. In meiosis, establishing tension requires at least one crossover per chromosome

neg: Pharyngula slits, which allow water to pass from the pharynx over the gills and out the body. In the other vertebrates, the grooves and pouches disappear. In humans, the chief trace of their existence is the eustachian tube and auditory canal which (interrupted only by the eardrum) connect the pharynx with the outside of the head. The existence of a common pharyngula stage for vertebrates was first proposed by German biologist Ernst Haeckel (1834–1919) in 1874. The observation of the conservation of animal morphology during the embryonic phylotypic period, where there is maximal similarity between the species within each animal phylum,

neg: Germ cell and a large mature egg, both being haploid cells. The polar bodies degenerate. Oocyte maturation stands by at metaphase II in most vertebrates. During ovulation, the arrested secondary oocyte leaves the ovary and matures rapidly into an egg ready for fertilization. Fertilization will cause the egg to complete meiosis II. In human females there is proliferation of the oogonia in the fetus, meiosis starts then before birth and stands by at meiotic division I up to 50 years, ovulation begins at puberty. A 10 - 20 μm large somatic cell generally needs 24 hours to double its mass for mitosis.

neg: Anatomical terms of location part of an appendage nearest to where it joins the body, and distal, literally meaning "standing away from" is used for the part furthest from the point of attachment. In all cases, the usage of terms is dependent on the body plan of the organism. For example, especially in organisms without distinct heads for reasons of broader applicability, "anterior" is usually preferred. As humans are approximately bilaterally symmetrical organisms, anatomical descriptions usually use the same terms as those for vertebrates and other members of the taxonomic group Bilateria. However, for historical and other reasons, standard human directional terminology has several

neg: Cerebellum larger in reptiles, considerably larger in birds, and larger yet in mammals. The large paired and convoluted lobes found in humans are typical of mammals, but the cerebellum is, in general, a single median lobe in other groups, and is either smooth or only slightly grooved. In mammals, the neocerebellum is the major part of the cerebellum by mass, but, in other vertebrates, it is typically the spinocerebellum. The cerebellum of cartilaginous and bony fishes is extraordinarily large and complex. In at least one important respect, it differs in internal structure from the mammalian cerebellum: The fish cerebellum does not

neg: Conoidasida Conoidasida Conoidasida is a class of parasitic alveolates in the phylum Apicomplexa. The class was defined in 1988 by Levine and contains two subclasses - the coccidia and the gregarines. All members of this class have a complete, hollow, truncated conoid. Gregarines tend to parasitize invertebrates with the mature gamonts being extracellular, the coccidia mostly infect vertebrates and have intracellular gamonts. A conoid is found in most species and when present forms complete but truncated cone. Sexual and asexual reproduction are present in life cycle of all species. Each zygote normally forms an oocyst wall within which it undergoes meiosis.

neg: Metarhizium anisopliae of malaria-transmitting mosquitoes is under investigation. "M. anisopliae" does not appear to infect humans or other vertebrates and is considered safe as an insecticide and as an acaricide. The microscopic spores are typically sprayed on affected areas. A possible technique for malaria control is to coat mosquito nets or cotton sheets attached to the wall with them. In August 2007, a team of scientists at the Indian Institute of Chemical Technology discovered a more efficient way of producing biodiesel which uses lipase, an enzyme produced in significant quantities by "M. anisopliae", as opposed to other reactions which use enzymes that

neg: Mosaic (genetics) to mark the wild-type chromosome as above, GAL80 serves this purpose, so that when it is removed by mitotic recombination, GAL4 is allowed to function, and GFP turns on. This results in the cells of interest being marked brightly in a dark background. In 1929, Alfred Sturtevant studied mosaicism in "Drosophila". A few years later, In the 1930s, Curt Stern demonstrated that genetic recombination, normal in meiosis, can also take place in mitosis. When it does, it results in somatic (body) mosaics. These are organisms which contain two or more genetically distinct types of tissue. The term "somatic mosaicism" was

neg: Primate basal ganglia and the oculomotor cortex, without significant connection to the motor cortex. Primate basal ganglia The basal ganglia form a major brain system in all species of vertebrates, but in primates (including humans) there are special features that justify a separate consideration. As in other vertebrates, the primate basal ganglia can be divided into striatal, pallidal, nigral, and subthalamic components. In primates, however, there are two pallidal subdivisions called the external globus pallidus (GPe) and internal globus pallidus (GPi). Also in primates, the dorsal striatum is divided by a large tract called the internal capsule into two masses named the caudate

neg: Immature ovum second stage of meiosis (meiosis II), and the daughter cells are one ootid and one polar body. Secondary oocytes are the immature ovum shortly after ovulation, to fertilization, where it turns into an ootid. Thus, the time as a secondary oocyte is measured in days. The secondary oocyte is the largest cell in the body, and in humans is just visible to the naked eye. An "ootid" is the haploid result of ootidogenesis. In oogenesis, it doesn't really have any significance in itself, since it is very similar to the ovum. However, it fills the purpose as the female counterpart

neg: Priscomyzon their evolutionary history is obscure. In ancient seas jawless vertebrate fish led to jawed fish, and thence to all other vertebrates, including humans. Being the only extant jawless vertebrates and a virtual time capsule of embryology and DNA, lampreys and hagfish are of immense scientific interest. Knowing the period during which they became parasitic would shed light on how typical they are of ancient fish. Having no bone tissue, effectively being essentially boneless, their cartilaginous framework leaves almost no fossil record - a mere three fossil species had previously been described, and in none of these was a sucker disc

neg: Panama disease thus attempts at meiosis in the plant's ovules cannot produce a viable gamete. Only rarely does the first reduction division in meiosis in the plants' flowers tidily fail completely, resulting in a euploid triploid ovule, which can be fertilized by normal haploid pollen from a diploid banana variety; a whole stem of bananas would contain only a few seeds and sometimes none. As a result, the resulting new banana variety is tetraploid, and thus contains seeds; the market for bananas is not accustomed to bananas with seeds. Experience showed that where both meiosis steps failed, causing a heptaploid seedling, or

neg: Overexploitation and Flora, or CITES was set up in order to control and regulate the trade in endangered animals. It currently protects, to a varying degree, some 33,000 species of animals and plants. It is estimated that a quarter of the endangered vertebrates in the United States of America and half of the endangered mammals is attributed to overexploitation. All living organisms require resources to survive. Overexploitation of these resources for protracted periods can deplete natural stocks to the point where they are unable to recover within a short time frame. Humans have always harvested food and other resources they have

neg: Synapsin dependent protein kinase), releasing the synaptic vesicles and allowing them to move to the membrane and release their neurotransmitter. Gene knockout studies in mice (where the mouse is unable to produce synapsin) have had some surprising results. Mice lacking all three synapsins are prone to seizures, and experience learning defects. These results suggest that while synapsins are not essential for synaptic function, they do serve an important modulatory role. Humans and most other vertebrates possess three genes encoding three different synapsin proteins. Each gene in turn is alternatively spliced to produce at least two different protein isoforms for a total

neg: Polysomy -"somy" is used to name aneuploid karyotypes. This is not to be confused with the suffix -"ploidy", referring to the number of complete sets of chromosomes. Polysomy is usually caused by non-disjunction (the failure of a pair of homologous chromosomes to separate) during meiosis, but may also be due to a translocation mutation (a chromosome abnormality caused by rearrangement of parts between nonhomologous chromosomes). Polysomy is found in many diseases, including Down syndrome in humans where affected individuals possess three copies (trisomy) of chromosome 21. Polysomic inheritance occurs during meiosis when chiasmata form between more than two homologous partners, producing

neg: Animal virus organs and tissues of the body and the outcomes range from mild or no symptoms, to life-threatening diseases. Humans cannot be infected by plant or insect viruses, but they are susceptible to infections with viruses from other vertebrates. These are called viral zoonoses or zoonotic infections. Examples include, rabies, yellow fever and pappataci fever. The viruses that infect other vertebrates are related to those of humans and most families of viruses that cause human diseases are represented. They are important pathogens of livestock and cause diseases such as foot-and-mouth disease and bluetongue. Jersey and Guernsey breeds of cattle are particularly

neg: Meiosis of the chromosomes and the disassembly of the spindle. Nuclear envelopes reform and cleavage or cell plate formation eventually produces a total of four daughter cells, each with a haploid set of chromosomes. Meiosis is now complete and ends up with four new daughter cells. Meiosis occurs in eukaryotic life cycles involving sexual reproduction, consisting of the constant cyclical process of meiosis and fertilization. This takes place alongside normal mitotic cell division. In multicellular organisms, there is an intermediary step between the diploid and haploid transition where the organism grows. At certain stages of the life cycle, germ cells produce

neg: Tail tail, even when such an appendage is located where the tail would be expected. Humans have a "tail bone" (the coccyx) attached to the pelvis, formed of fused vertebrae, usually four, at the bottom of the vertebral column. It does not protrude externally. Tail The tail is the section at the rear end of an animal's body; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammals, reptiles, and birds. While tails are primarily a feature of vertebrates, some invertebrates

neg: Albinism in humans all vertebrates, including humans. It is due to absence or defect of tyrosinase, a copper-containing enzyme involved in the production of melanin. It is the opposite of melanism. Unlike humans, other animals have multiple pigments and for these, albinism is considered to be a hereditary condition characterised by the absence of melanin in particular, in the eyes, skin, hair, scales, feathers or cuticle. While an organism with complete absence of melanin is called an albino, an organism with only a diminished amount of melanin is described as leucistic or albinoid. The term is from the Latin "albus", "white". There are

neg: Kinetochore Kinetochore A kinetochore (, ) is a disc-shaped protein structure associated with duplicated chromatids in eukaryotic cells where the spindle fibers attach during cell division to pull sister chromatids apart. The kinetochore assembles on the centromere and links the chromosome to microtubule polymers from the mitotic spindle during mitosis and meiosis. Its proteins also help to hold the sister chromatids together and play a role in chromosome editing. "Monocentric" organisms, including vertebrates, fungi, and most plants, have a single centromeric region on each chromosome which assembles a single, localized kinetochore. "Holocentric" organisms, such as nematodes and some plants, assemble a

neg: Animal virus Animal virus Animal viruses are viruses that infect animals. Viruses infect all cellular life and although viruses infect every animal, plant and protist species, each has its own specific range of viruses that often infect only that species. The viruses of vertebrates are informally distinguished between those that primarily cause infections of humans and those that infect other animals. The two fields of study are called medical (or clinical) virology and veterinary virology respectively. Although not the first viruses to be discovered and characterised, those that cause infections of humans are the most studied. Different viruses can infect all the

neg: Motor learning after a practice period where it was present or not, does not cause performance to deteriorate. Alternating motor learning and physical practice can ultimately lead to a great, if not better performance as opposed to just physical practice. The cerebellum and basal ganglia are critical for motor learning. As a result of the universal need for properly calibrated movement, it is not surprising that the cerebellum and basal ganglia are widely conserved across vertebrates from fish to humans. Through motor learning the human is capable of achieving very skilled behavior, and through repetitive training a degree of automaticity can be

neg: 1q21.1 duplication syndrome up till now are: <br> It is not clear whether the list of symptoms is complete. Very little information is known about the syndrome. The symptomology may be different among individuals, even in the same family. Meiosis is the process of dividing cells in humans. In meiosis, the chromosome pairs splits and a representative of each pair goes to one daughter cell. In this way the number of chromosomes will be halved in each cell, while all the parts on the chromosome (genes) remain, after being randomized. Which information of the parent cell ends up in the daughter cell is

neg: Chromosome be thousands of copies per cell. Asexually reproducing species have one set of chromosomes that are the same in all body cells. However, asexual species can be either haploid or diploid. Sexually reproducing species have somatic cells (body cells), which are diploid [2n] having two sets of chromosomes (23 pairs in humans with one set of 23 chromosomes from each parent), one set from the mother and one from the father. Gametes, reproductive cells, are haploid [n]: They have one set of chromosomes. Gametes are produced by meiosis of a diploid germ line cell. During meiosis, the matching chromosomes of

neg: Synapsis the purging of the detrimental. Following synapsis, a type of recombination referred to as synthesis dependent strand annealing (SDSA) occurs frequently. SDSA recombination involves information exchange between paired non-sister homologous chromatids, but not physical exchange. SDSA recombination does not cause crossing-over. Both the non-crossover and crossover types of recombination function as processes for repairing DNA damage, particularly double-strand breaks (see Genetic recombination). The central function of synapsis is therefore the identification of homologues by pairing, an essential step for a successful meiosis. The processes of DNA repair and chiasma formation that take place following synapsis have consequences at many levels,

neg: Cell (biology) the S phase of the cell cycle. In meiosis, the DNA is replicated only once, while the cell divides twice. DNA replication only occurs before meiosis I. DNA replication does not occur when the cells divide the second time, in meiosis II. Replication, like all cellular activities, requires specialized proteins for carrying out the job. Between successive cell divisions, cells grow through the functioning of cellular metabolism. Cell metabolism is the process by which individual cells process nutrient molecules. Metabolism has two distinct divisions: catabolism, in which the cell breaks down complex molecules to produce energy and reducing power, and

neg: Meiosis by the location of the organism phase(s). In the "diplontic life cycle" (with pre-gametic meiosis), of which humans are a part, the organism is diploid, grown from a diploid cell called the zygote. The organism's diploid germ-line stem cells undergo meiosis to create haploid gametes (the spermatozoa for males and ova for females), which fertilize to form the zygote. The diploid zygote undergoes repeated cellular division by mitosis to grow into the organism. In the "haplontic life cycle" (with post-zygotic meiosis), the organism is haploid instead, spawned by the proliferation and differentiation of a single haploid cell called the gamete.

neg: FAM203B ends at the same location for all homologs, while the DUF384 domain starts and ends at roughly the same location in all homologs. There is high homology in the DUF384 domain (292..349) and in the DUF383 domain (154..288), and several amino acids are completely conserved in vertebrates, invertebrates, plants, and fungi, which include Arg190, Gly219, Asn226, Lys273, and Lys338. Other highly conserved amino acids include Asn87, Lys88, Arg216, and Phe229. FAM203B Family with Sequence Similarity 203, Member B (FAM203B) is a protein encoded by the "FAM203B" gene (8q24.3) in humans. While FAM203B is only found in humans and possibly non-human

neg: Gametocyte Gametocyte A gametocyte is a eukaryotic germ cell that divides by mitosis into other gametocytes or by meiosis into gametids during gametogenesis. Male gametocytes are called "spermatocytes", and female gametocytes are called "oocytes". The development of gametogonia to primary gametocytes is called "gametocytogenesis". The further development of primary gametocytes to secondary gametocytes is a part of gametidogenesis. Gametogenesis is the formation or production of gametes (taking place during meiosis). The development and maturation of sex cells also takes place during meiosis. Gametogenesis is also the process of formation in male and female gametes that occur in the gonads (ovary and

neg: Tc1/mariner Tc1/mariner Tc1/mariner is a class of interspersed repeats DNA transposons. The elements of this class are found in all animals, including humans. They can also be found in protists. The class is named after its two best-studied members, the Tc1 transposon of "Caenorhabditis elegans" and the mariner transposon of "Drosophila". Tc1 is a transposon active in "Caenorhabditis elegans". There are also Tc1-like transposons in humans, all inactive. Tc1-like elements are present in other lower vertebrates, including several fish species and amphibians. In "C. elegans", it is a 1610 base-pair long sequence. Experiments show that this element "jumps" in human cells,

neg: RAD51 of meiosis-specific DMC1, are essential for development in mammals. Rad51 is a member of the RecA-like NTPases. In humans, RAD51 is a 339-amino acid protein that plays a major role in homologous recombination of DNA during double strand break repair. In this process, an ATP dependent DNA strand exchange takes place in which a template strand invades base-paired strands of homologous DNA molecules. RAD51 is involved in the search for homology and strand pairing stages of the process. Unlike other proteins involved in DNA metabolism, the RecA/Rad51 family forms a helical nucleoprotein filament on DNA. This protein can interact with

neg: MHC class I most recent common ancestor of all jawed vertebrates, and have been found in all living jawed vertebrates that have been studied thus far. Since their emergence in jawed vertebrates, this gene family has been subjected to many divergent evolutionary paths as speciation events have taken place. There are, however, documented cases of trans-species polymorphisms in MHC class I genes, where a particular allele in an evolutionary related MHC class I gene remains in two species, likely due to strong pathogen-mediated balancing selection by pathogens that can infect both species. Birth-and-death evolution is one of the mechanistic explanations for the size

neg: Schistosomatidae features. "Sinobilharzia" is a genus that is no longer considered valid. Schistosomatidae Schistosomatidae is a family of digenetic trematodes with complex parasitic life cycles. Immature developmental stages of schistosomes are found in molluscs and adults occur in vertebrates. The best studied group, the blood flukes of the genus "Schistosoma", infect and cause disease in humans. Other genera which are infective to non-human vertebrates can cause mild rashes in humans. Schistosomatids are dioecious (individuals are of separate sexes) which is exceptional with regards to their phylum, Platyhelminthes, in which most species are hermaphrodidic (individuals possess both male and female reproductive systems).

neg: Schistosomatidae Schistosomatidae Schistosomatidae is a family of digenetic trematodes with complex parasitic life cycles. Immature developmental stages of schistosomes are found in molluscs and adults occur in vertebrates. The best studied group, the blood flukes of the genus "Schistosoma", infect and cause disease in humans. Other genera which are infective to non-human vertebrates can cause mild rashes in humans. Schistosomatids are dioecious (individuals are of separate sexes) which is exceptional with regards to their phylum, Platyhelminthes, in which most species are hermaphrodidic (individuals possess both male and female reproductive systems). The eggs of these parasites were first seen by Theodor Bilharz,

neg: Cerebellum Cerebellum The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebellum plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language as well as in regulating fear and pleasure responses, but its movement-related functions are the most solidly established. The human cerebellum does not initiate movement, but contributes to coordination, precision, and accurate timing: it receives

neg: Shorthead redhorse are eaten by northern pike and muskellunge. The shorthead redhorse does not actively compete for food. Because of their wide range of prey and eating the most vertebrates of all the suckers, they do not have a competitor. Humans impact shorthead redhorse habitat. The construction of dams blocked free flowing rivers like the Mississippi in which they live, disrupting their spawning migration routes. Shorthead redhorse are killed easily by pollutants in the water. “The upstream migratory range of shorthead redhorse in a Maryland river decreased due to an increase in chlorinated sewage outfalls”. Factory pollutants are dumped into streams or

neg: PTPRT paxillin that is incapable of being tyrosine phosphorylated, the paxillin Y88F mutant, these cells exhibit reduced tumorigenicity. This suggests that PTPrho may function as a tumor suppressor protein by regulating paxillin phosphorylation. PTPrho has been shown to interact with: PTPRT Receptor-type tyrosine-protein phosphatase T is an enzyme that in humans is encoded by the "PTPRT" gene. PTPRT is also known as PTPrho, PTPρ and human accelerated region 9. The human accelerated regions are 49 regions of the human genome that are conserved among vertebrates, but in humans show significant distinction from other vertebrates. This region may, therefore, have played a

neg: Flavivirus require mosquito vectors, but are well-enough adapted to humans as to not necessarily depend upon animal hosts (although they continue to have important animal transmission routes, as well). Other virus transmission routes for arboviruses include handling infected animal carcasses, blood transfusion, child birth and consumption of unpasteurised milk products. Transmission from nonhuman vertebrates to humans without an intermediate vector arthropod is thought to be unlikely. For example, early tests with yellow fever showed that the disease is not contagious. The known non-arboviruses of the flavivirus family reproduce in either arthropods or vertebrates, but not both, with one odd member of

neg: Collared peccary subtropical grasslands, savannas, and shrublands, flooded grasslands and savannas, tropical and subtropical dry broadleaf forests, and several other habitats, as well. In addition, it is well adapted to habitats shared by humans, merely requiring sufficient cover; they can be found in cities and agricultural land throughout their range, where they consume garden plants. Notable populations are known to exist in the suburbs of Phoenix and Tucson, Arizona. Collared peccaries normally feed on cactus, mesquite beans, fruits, roots, tubers, palm nuts, grasses, invertebrates, and small vertebrates. In areas inhabited by humans, they will also consume cultivated crops and ornamental plants, such

neg: 1q21.1 copy number variations mental retardation and various physical anomalies. Meiosis is the process of dividing cells in humans. In meiosis, the chromosome pairs splits and a representative of each pair goes to one daughter cell. In this way the number of chromosomes will be halved in each cell, while all the parts on the chromosome (genes) remain, after being randomized. Which information of the parent cell ends up in the daughter cell is purely decided by chance. Besides this random process, there is a second random process. In this second random process the DNA will be scrambled in a way that pieces are

neg: Homologous chromosome the same in mitosis as they do in meiosis. Prior to every single mitotic division a cell undergoes, the chromosomes in the parent cell replicate themselves. The homologous chromosomes within the cell will ordinarily not pair up and undergo genetic recombination with each other. Instead, the replicants, or sister chromatids, will line up along the metaphase plate and then separate in the same way as meiosis II - by being pulled apart at their centromeres by nuclear mitotic spindles. If any crossing over does occur between sister chromatids during mitosis, it does not produce any new recombinant genotypes. Homologous pairing

neg: 1q21.1 deletion syndrome Very little information is known about the syndrome. The syndrome can have completely different effects on members of the same family. A common deletion is between 1.0–1.9Mb. Mefford states that the standard for a deletion is 1.35Mb. The largest deletion seen on a living human is over 5 Mb. Meiosis is the process of dividing cells in humans. In meiosis, the chromosome pairs split and a representative of each pair goes to one daughter cell. In this way the number of chromosomes will be halved in each cell, while all the parts on the chromosome (genes) remain, after being randomized.

neg: RMI1 of aberrant recombination intermediates. In particular, the TOP3-RMI1–SGS1 complex promotes early formation of non-crossover recombinants during meiosis. RMI1 RecQ-mediated genome instability protein 1 is a protein that in humans is encoded by the "RMI1" gene. During meiosis in budding yeast "Saccharomyces cerevisiae", TOP3 (a type I topoisomerase) and its accessory factor RMI1 form a heterodimer that functions to allow passage of one DNA single strand through another. The TOP3-RMI1 heterodimer associates with Sgs1 (Bloom helicase ortholog) to form a complex that catalyzes dissolution of double Holliday junctions. Furthermore, the TOP3-RMI1 heterodimer participates in all meiotic recombination functions associated with Sgs1,

neg: Tetrahymena Rad 51 protein levels. These findings suggest that ciliates such as "T. thermophila" utilize a Rad51-dependent recombinational pathway to repair damaged DNA. The Rad51 recombinase of "T. thermophila" is a homolog of the "Escherichia coli" RecA recombinase. In "T. thermophila", Rad51 participates in homologous recombination during mitosis, meiosis and in the repair of double-strand breaks. During conjugation, Rad51 is necessary for completion of meiosis. Meiosis in "T. thermophila" appears to employ a Mus81-dependent pathway that does not use a synaptonemal complex and is considered secondary in most other model eukaryotes. This pathway includes the Mus81 resolvase and the Sgs1 helicase.

neg: Chiasma (genetics) good predictor of the number of crossovers. Yet, in humans and possibly other species, evidence shows that the number of crossovers is regulated at the level of an entire chromosome and not an arm. The grasshopper "Melanoplus femurrubrum" was exposed to an acute dose of X-rays during each individual stage of meiosis, and chiasma frequency was measured. Irradiation during the leptotene-zygotene stages of meiosis, that is, prior to the pachytene period in which crossover recombination occurs, was found to increase subsequent chiasma frequency. Similarly, in the grasshopper "Chorthippus brunneus", exposure to X-irradiation during the zygotene-early pachytene stages caused a significant

neg: The Julekalender key to wind up the music box is. He gives them "The Big Book" to take with them, an ancient tome that contains the answer to any and all questions, warning them to take great care that it does not fall into the hands of a Nå-såer. If this were to happen, all would be lost. They are also warned to take care, as the Nå-såere nowadays have taken the appearance of normal humans, but when they consume alcohol, they regain their original appearance, with fangs, and thick-rimmed glasses. The three merrily set off, and this is where the first

neg: Anatomical terms of location the posterior row. In some species the curve is so gross that the eyes apparently are arranged into two anteroposterior parallel rows of eyes. Categories: Anatomical terms of location Standard anatomical terms of location deal unambiguously with the anatomy of animals, including humans. All vertebrates (including humans) have the same basic body plan they are strictly bilaterally symmetrical in early embryonic stages and largely bilaterally symmetrical in adulthood. That is, they have mirror-image left and right halves if divided down the middle. For these reasons, the basic directional terms can be considered to be those used in vertebrates. By extension,

neg: Jan Klein many phylogenies of so-called adaptive radiations will remain unresolved. One such case is the radiation that gave rise to the tetrapods in the evolution of jawed vertebrates. In this case, Klein's group has demonstrated that increasing the number of genes in the input database does not improve the resolution power of the output phylogenetic trees. Three critical assumptions underlie the study of "Mhc" evolution: First, the "Mhc" is absent in all non-vertebrates. Second, jawless vertebrates (Agnatha) are monophyletic and are a sister group of jawed vertebrates (Gnathostoma). And third, jawless vertebrates lack the "Mhc", which is present in all the

neg: Retinal regeneration Retinal regeneration Retinal regeneration refers to the restoration of vision in vertebrates that have suffered retinal lesions or retinal degeneration. The two most well-studied mechanisms of retinal regeneration are cell-mediated regeneration and cellular transplantation. Regenerative processes may have applications in humans for treating degenerative retinal diseases, such as retinitis pigmentosa. While mammals, such as humans and mice, lack the innate ability to regenerate the retina, lower vertebrates, such as teleost fish and salamanders, are capable of regenerating lost retinal tissue in the event of damage. Zebrafish, like other teleost fish, possess the innate ability to regenerate retinal damage. This ability

neg: Fungus are a basal group divergent from the other fungal phyla, consisting of four major clades with suggestive evidence for paraphyly or possibly polyphyly. The Blastocladiomycota were previously considered a taxonomic clade within the Chytridiomycota. Recent molecular data and ultrastructural characteristics, however, place the Blastocladiomycota as a sister clade to the Zygomycota, Glomeromycota, and Dikarya (Ascomycota and Basidiomycota). The blastocladiomycetes are saprotrophs, feeding on decomposing organic matter, and they are parasites of all eukaryotic groups. Unlike their close relatives, the chytrids, most of which exhibit zygotic meiosis, the blastocladiomycetes undergo sporic meiosis. The Neocallimastigomycota were earlier placed in the phylum Chytridomycota.

neg: Homologous chromosome their allelic forms since one was inherited from the mother and one from the father. So humans have two homologous chromosome sets in each cell, meaning humans are diploid organisms. Homologous chromosomes are important in the processes of meiosis and mitosis. They allow for the recombination and random segregation of genetic material from the mother and father into new cells. Meiosis is a round of two cell divisions that results in four haploid daughter cells that each contain half the number of chromosomes as the parent cell. It reduces the chromosome number in a germ cell by half by first

neg: Microsporidia percent of the species are parasites of vertebrates—including humans, in which they can cause microsporidiosis. After infection they influence their hosts in various ways and all organs and tissues are invaded, though generally by different species of microsporidia. Some species are lethal, and a few are used in biological control of insect pests. Parasitic castration, gigantism, or change of host sex are all potential effects of microsporidian parasitism (in insects). In the most advanced cases of parasitism the microsporidium rules the host cell completely and controls its metabolism and reproduction, forming a xenoma. Replication takes place within the host's cells,

neg: Disgaea multiple endings. However, each time, the player's party, with all characters, items, and abilities, are carried over. This New Game Plus allows the player to develop extremely powerful characters, approaching the maximum character level of 9999 and 186,000 combined levels in reincarnation through repeated playthroughs. The series exists for the moment only in Japanese, English and French languages. All "Disgaea" games take place mostly in the "Netherworld", a parallel universe inhabited by demons where moral values are reversed from those of humans. Multiple Netherworlds exist, each with their own Overlord. Other areas include the human world, shown to possess a

neg: Scientific terminology the name applied to muscles. During the last two centuries there has been an increasing tendency to modernise the terminology, though how beneficial that might be is subject to discussion. In other descriptive anatomical terms, whether in vertebrates or invertebrates, a "frenum" (a structure for keeping something in place) is simply the Latin for a bridle; and a "foramen" (a passage or perforation) also is the actual Latin word. All such words are so much terminology. It does not much matter whether modern users know that they are classical or not. Some distinct term is necessary for any meaningful concept,

neg: Maternal Behaviour in Vertebrates unable to thermoregulate. This is achieved through the utilization of pouches in marsupial species, and the construction of nests in rodents and other altricial species. Because the young are not capable of locomotion, many other maternal behaviours take place at the nest as well, including feeding, nursing and grooming (licking). Members of this species are unable to recognize their own young and therefore will care for all the young in the nest equally, regardless of whether or not it is their own offspring. Once the young reach a point in their sensory, and motor development and no longer require the

neg: Holliday junction respectively, can promote Holliday junction resolution in vivo, absence of all three nucleases has only a modest impact on formation of crossover products. Double mutants deleted for both MLH3 (major pathway) and MMS4 (minor pathway) showed dramatically reduced crossing over compared to wild-type (6- to 17-fold); however spore viability was reasonably high (62%) and chromosomal disjunction appeared mostly functional. Although MUS81 is a component of a minor crossover pathway in the meiosis of budding yeast, plants and vertebrates, in the protozoan "Tetrahymena thermophila", MUS81 appears to be part of an essential, if not the predominant crossover pathway. The MUS81 pathway

neg: DMC1 (gene) meiotic genes. The Dmc1 protein is one of two homologs of RecA found in eukaryotic cells, the other being Rad51. In budding yeast, Rad51 serves as a strand exchange protein in mitosis where it is critical for the repair of DNA breaks. Rad51 is converted to an accessory factor for Dmc1 during meiosis by inhibition of its strand exchange activity. Homologs of DMC1 have been identified in many organisms including divergent fungi, plants and mammals including humans. The DMC1 gene and protein were discovered in the budding yeast S. cerevisiae by Douglas Bishop when he was a postdoctoral fellow in

neg: Origin and function of meiosis Meanwhile, two of the other novel features appear to be simply modified, and extensive recombination could have evolved later. If meiosis arose from prokaryotic transformation, during the early evolution of eukaryotes, mitosis and meiosis could have evolved in parallel, with both processes using common molecular components, where mitosis evolved from the molecular machinery used by prokaryotes for DNA replication and segregation, and meiosis evolved from the prokaryotic sexual process of transformation, but meiosis also made use of the evolving molecular machinery for DNA replication and segregation. Abundant evidence indicates that facultative sexual eukaryotes tend to undergo sexual reproduction under stressful

neg: Excretion Excretion Excretion is a process by which metabolic waste is eliminated from an organism. In vertebrates this is primarily carried out by the lungs, kidneys and skin. This is in contrast with secretion, where the substance may have specific tasks after leaving the cell. Excretion is an essential process in all forms of life. For example, in mammals urine is expelled through the urethra, which is part of the excretory system. In unicellular organisms, waste products are discharged directly through the surface of the cell. During life activities such as cellular respiration, several chemical reactions take place in the body.