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| | spermatozoon |
 | | However, from the moral aspect, the fecundated egg, from the moment of the penetration of the spermatozoon, has to be respected and treated as a human person... | | | The fecundated egg, from the moment of the penetration of the spermatozoon, has to be respected and treated as a human person, Archbishop Joseph Mercieca, Gozo... | | | ...bishops said that from the moral aspect, the fecundated egg has to be respected and treated as a human person from the moment of penetration of the spermatozoon... |
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http://www.mongabay.com/igapo/biotech/spermatozoon.html
(181 words)
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| | Dissertation of Michael F. Guyer on Spermatogenesis in Pigeons |
| | This interpretation is, of course, as yet little more than a suggestion, and it is offered merely as an interesting possibility and as the only explanation the writer has been able to conceive of concerning the remarkable diminution in the number of the chromosomes from sixteen to four. | | | Numerous linin fibers radiate out from this core of chromatin to the periphery of the nucleus, and frequently bridges or twigs of chromatin may be observed extending out along them to connect with the inner surface of the deeply stained nuclear wall. | | | Nothing further could be determined concerning the centrosomes as they become lost to view at this point. |
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http://crystal.biochem.queensu.ca/forsdyke/guyer01.htm
(13143 words)
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| | [No title] |
| | The method of claim 1, wherein the step of fertilizing the reconstituted recipient oocyte comprises inserting a whole spermatozoon or a spermatozoon head or a demembranated spermatozoon head into the oocyte. | | | Fertilization of the oocytes may be achieved with live spermatozoa by in vitro methods known to those skilled in the art, wherein the live spermatozoa pass through the oocyte's vestments by themselves, then fuses with the | | | Embryonic development may then be facilitated to allow the resulting embryo to develop into a live offspring. |
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http://www.wipo.int/cgi-pct/guest/getbykey5?KEY=00/01806.000113&ELEMENT_SET=DECL
(8331 words)
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| | Developmental Biology Online: Anton von Leeuwenhoek and his perception of spermatozoa |
| | Indeed, wrote Leeuwenhoek in 1679, there may be as many parts in the sperm as in the human body itself (41). | | | Leeuwenhoek's own observations of early embryonic development had offered no less striking evidence against the animal's presence in the spermatozoon as a miniature replica; indeed, in extreme instances, those observations would have been perceived by observers with other predispositions as testifying conclusively that there was no persisting animal structure there at all. | | | Even the dissected body of a young free-swimming tadpole seemed to be composed of globules alone, with no intestines, nerves, or vessels. |
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http://www.devbio.com/printer.php?ch=7&id=65
(5596 words)
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| | The Importance of Sperm Morphology in the Evaluation of Male Infertility |
| | Kruger’s criteria) use the examination of spermatozoa that had penetrated cervical mucus for the definition of normal spermatozoon. | | | For example, the techniques for preparing morphology specimens have been expanded from three to five. | | | However, the definition of a normal spermatozoon as described by WHO in 1992 is different from that used by other authors (17,21,22,31). |
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http://www.gfmer.ch/Endo/PGC_network/Sperm_morphology.htm
(3765 words)
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| | Spermotzoa, spermatozoon, Acrosome, fertilisation, fertilization - 2 |
| | If you have ANY concerns about your health, please see your doctor immediately and do not rely solely on information found here or anywhere else on the internet. | | | The production of spermatozoa is continuous throughout a man's life, however each spermatozoon has a limited life-span. |
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http://www.paternityangel.com/Articles_zone/How_it_happens/How2.htm
(207 words)
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| | STAGES OF DEVELOPMENT from ovum/sperm to newborn baby |
| | Do not rely on this information for medical decisions. | | | STAGES OF DEVELOPMENT from ovum/sperm to newborn baby | | | Most people consider them to be a form of human life, because they appear alive and contain human DNA. |
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http://www.religioustolerance.org/abo_fetu.htm
(1846 words)
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| | Gametes - The Spermatozoon - Cambridge University Press |
| | provides an integrated and multidisciplinary view of the spermatozoon... | | | This volume, and its companion volume on the oocyte, provide an authoritative and wide-ranging account of the gametes, and their reproductive role and function in humans. | | | The volume starts with an evolutionary perspective before focusing on the molecular and cellular biology of the sperm cell, and its structure and function. |
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http://www.cambridge.org/uk/catalogue/catalogue.asp?isbn=0521479967
(500 words)
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| | PROTEST AT THE VATICAN MISSION TO THE U.N. |
| | When confronted with scientific research showing that intact condoms are an effective barrier against sexually transmitted diseases, Lopez Trujillo said: "They are wrong about that; this is an easily recognizable fact," according to the BBC. | | | The spermatozoon can easily pass through the 'net' that is formed by the condom." That latex has holes or pores through which HIV (or sperm) can pass is a total canard. | | | A National Institutes of Health panel that included anti-condom advocates examined the effectiveness of condoms from just about every perspective, including strength and porosity; according to its report, released in July 2001, latex condoms are impermeable to even the smallest pathogen. |
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http://www.actupny.org/reports/vatican_nyc.html
(4030 words)
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| | Spermplaty: a bibliography on sperm of Platyhelminthes |
| | Ultrastructure of spermiogenesis and the spermatozoon of Mathevotaenia herpestis (Cestoda), intestinal parasite of Atelerix albiventrix in Senegal. | | | Ultrastructure of spermiogenesis and the spermatozoon of Anoplocephaloides dentata (Cestoda, Cyclophyllidea, Anoplocephalidae), intestinal parasite of Arvicolidae rodents. | | | Comparative ultrastructural study of spermiogenesis in Monogeneans (Flatworms). |
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http://www.mnhn.fr/mnhn/bpph/Data/Spermplaty
(6544 words)
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| | Dorlands Medical Dictionary |
| | a spermatozoon that cannot adhere to the ovum, such as when the acrosome is deficient. | | | Spermatozoa, formed in the seminiferous tubules, are derived from spermatogonia, which first develop into spermatocytes, which, in turn, undergo meiosis to produce spermatids; the spermatids then differentiate into spermatozoa. | | | (sper´mə-tid) a cell derived from a secondary spermatocyte by fission, and capable of undergoing spermiogenesis to develop into a spermatozoon; called also spermatoblast. |
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http://www.mercksource.com/pp/us/cns/cns_hl_dorlands.jspzQzpgzEzzSzppdocszSzuszSzcommonzSzdorlandszSzdorlandzSzdmd_s_17zPzhtm
(3340 words)
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| | STAZIONE ZOOLOGICA ANTON DOHRN - Activity Report 1991 |
| | The research conducted by Dr. De Santis’s group is aimed at determining the mechanisms that regulate the preliminary processes of sperm-egg interaction and the molecules involved in them, on both the egg and the spermatozoon. | | | As to the counterpart of the FP on the spermatozoon, a fucosidase has been isolated from spermatozoa, which appears to play a role in the early stages of the interaction with the VC. | | | In particular, Dr. Dale wishes to determine the nature of the factors in the spermatozoon responsible for egg activation and to establish the role of the phosphoinositide cycle of the sperm. |
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http://www.szn.it/actrep91/aqua_2.htm
(2561 words)
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| | [No title] |
| | Binding of the spermatozoon to these receptors is apparently required for breakdown of the acrosome within the spermatozoon and thus the release of enzymes that will disrupt the zona pellucida, allowing the spermatozoon to enter the oocyte. | | | Spermiation - This term describes the release of the spermatozoon from the seminal epithelium into the lumen of the seminiferous tubule. | | | Spermiogenesis - This is the process of cytoplasmic maturation that converts a spermatid to a spermatozoon. |
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http://cna.uc.edu/embryology/glossaries/CH1.doc
(3892 words)
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| | Search Results for Spermatozoon - Encyclopædia Britannica |
| | Despite the many early descriptions of spermatozoa, their essential role in fertilization was not proven until 1879, when Hermann Fol, a Swiss physician and zoologist, observed the penetration of a... | | | The acrosome reaction of spermatozoa is a prerequisite for the association between a spermatozoon and an egg, which occurs through fusion of their plasma membranes. | | | Maturation is the final step in the production of functional eggs (oogenesis) that can associate with a spermatozoon and develop a reaction that prevents the entry of more than one spermatozoon; in... |
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http://www.britannica.com/search?query=Spermatozoon
(281 words)
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| | Fertility Clinic - The various laboratory stages |
| | The latter is indicated in case of severe sperm impairment, in case of fertilisation problems during a previous attempt at in vitro fertilisation, and in cases where the sperm has been retrieved directly by surgical means in the testicle or canals (ductus deferens or epididymis). | | | Whenever fusion of the spermatozoon with the oocyte is difficult to achieve, fertilisation may be carried out by the direct microinjection of a spermatozoon inside the oocyte or I.C.S.I. (see following page). | | | This is done in culture medium, a liquid which provides the oocytes the proper conditions of temperature, atmosphere and humidity close to those found in the fallopian tube (the natural fertilisation site). |
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http://www.ulb.ac.be/erasme/edu/FIV/en/C4.htm
(987 words)
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| | anatomy and physiology of male reproductive system |
| | Acrosome reacted spermatozoon may pass through zona pellucida into the perivitelline space (this process may take about 1 hour). | | | Actual molecular signalling mechanism for the sperm acrosome reaction is very poorly understood. | | | Type B spermatogonia is converted into primary spermatocyte which divides to secondary spermatocyte and divide again to form round spermatids.3. |
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http://www.uhmc.sunysb.edu/urology/male_infertility/anatomy_and_physiology_of_male_reproductive_system.html
(772 words)
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| | [No title] |
| | The second part is induction of the acrosome reaction within a spermatozoon. | | | and produces the acrosome reaction after less than 30 minutes of exposure to the spermatozoon. | | | The two parts can be detected by a number of procedures that are known to the skilled artisan. |
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http://www.wipo.int/cgi-pct/guest/getbykey5?KEY=99/42581.990826&ELEMENT_SET=DECL
(8618 words)
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| | ARS Publication request: FERTILIZATION |
| | Binding of sperm to the ZP initiates the acrosome reaction and exocytosis of its content, which enables the spermatozoon to penetrate the ZP. | | | Technical Abstract: Fertilization is a complex process by which mammalian male (spermatozoon) and female (oocyte or ovum) haploid gametes unite to produce a totipotent diploid zygote that develops into a genetically distinct individual. | | | Ovulated oocytes/ova are surrounded by the ZP, a viscoelastic, spherical, extracellular matrix composed of three glycoproteins (ZP1, ZP2, and ZP3), which provide both structural form and species-specific receptor-ligand binding between the egg extracellular matrix and sperm. |
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http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=162833
(303 words)
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| | Volume 47/Number 2/Abstract 04 |
| | Aissatou Ba (1), Cheikh Tidiane Ba (1)*, Marchand Bernard (2) - Ultrastructural study of the spermatozoon of Echinocotyle dolosa (Cestoda, Cyclophyllidea, Hymenolepididae). | | | This type of polylobulation has never been described in a cestode. | | | Similarly, an apical disc of electron-dense material has never been observed in a cestode spermatozoon; nor has a nucleus of roughly 0.3-0.7 |
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http://www.actaparasitologica.pan.pl/archive/47/toc47204.html
(258 words)
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| | Microtubular System during Spermiogenesis and in the Spermatozoon of Convoluta saliens (Platyhelminthes, Acoela): ... |
| | Microtubular System during Spermiogenesis and in the Spermatozoon of Convoluta saliens (Platyhelminthes, Acoela): Tubulin Immun | | | It is established that the nucleus, after a stage of elongation, does not migrate up to the distal extremity of the spermatid, and that the centriolar derivatives are located at the distal extremity of the shaft. | | | Spermiogenesis and the spermatozoon were studied in Convoluta saliens, an acoel platyhelminth, by transmission electron microscopy, labelling of nuclei and immunocytochemistry of tubulin with various antibodies. |
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http://www.mnhn.fr/mnhn/bpph/Equipes/Justine/Jpublications/Jabst141.html
(236 words)
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| | The Sponges of BC |
| | The microstrongyles may be absent or may be microxeas or centrotylote. | | | Koltun 1966 reports microstrongyles 15--45µ and for Suberites domuncula spermatozoon 13--52µ by 1--4µ. |
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http://www.interchg.ubc.ca/csmecher/suberite.s/domuncul.htm
(387 words)
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| | fertilization - urchin |
| | Adhesion of the spermatozoon to the surface of the ovum. | | | Spermatozoon penetrating by the acrosome through the mucous membrane of the egg. |
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http://www.ulb.ac.be/sciences/biodic/EImFecon.html
(52 words)
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| | [Frontiers in Bioscience 3, e39-48, April 30, 1998] |
| | One of the crucial steps in the fertilization process is the attachment of the spermatozoon to the ZP of the ovum, which requires specific recognition and interaction between the complementary molecules (19,20). | | | Although whole spermatozoon can produce an antibody response that is capable of inducing infertility in humans, they cannot per se be employed for the development of a vaccine (8,9). | | | These data indicate that the spermatozoon has both auto- as well as isoantigenic potentials, and when sufficient antibody titers are present, it can cause infertility in humans. |
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http://www.bioscience.org/1998/V3/e/naz/e39-48.htm
(3934 words)
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| | Volume 48/Number 4/Abstract 03 |
| | To discuss the phylogenetic relationships, comparison is made with Opecoeloides furcatus, the only other opecoeloid for which the reproduction characters were described. | | | Despite these features, there are some other peculiarities that distinguish the spermatozoon of H. | | | A centriolar derivative and a lateral expansion were observed in the anterior region. |
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http://www.actaparasitologica.pan.pl/archive/48/toc48142.html
(188 words)
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| | spermatozoon - OneLook Dictionary Search |
| | Phrases that include spermatozoon: a of spermatozoon, fibrous s. | | | spermatozoon : The On-line Medical Dictionary [home, info] | | | Words similar to spermatozoon: sperm, spermatozoa, spermatozoal, sperm cell, more... |
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http://www.onelook.com/?w=spermatozoon&ls=a
(203 words)
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| | [No title] |
| | The union of a spermatozoon and ovum marks the beginning of a new life. | | | The nuclear membrane of the spermatozoon dissipates and its chromatin is released into the ooplasm; this material becomes surrounded with a new membrane to form the male pronucleus. | | | Initial contact and fusion of a spermatozoon with the secondary oocyte occurs near the equatorial border of the head of the sperm cell (Figure 5-16). |
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http://www.uwyo.edu/wjm/repro/fert.htm
(954 words)
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| | Frontiers in Bioscience 1, d146-160, August 1, 1996 |
| | Following stimulation by ZP3, the spermatozoon undergoes the AR. | | | In response to an oocyte-derived signal or signals, at the time of fertilization of the oocyte, the spermatozoon undergoes acrosomal exocytosis (37). | | | The generally accepted view is that the fertilizing spermatozoon traverses the cumulus oophorus using the hyaluronidase activity present in the protein PH20, located on the plasma membrane of the posterior head (107). |
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http://www.bioscience.org/1996/v1/d/morales1/htmls/9.htm
(924 words)
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| | Life of Riley: Mr spermatozoon finds a home |
| | With such chronically high unemployment among the fruits of many a gentlemen's loins, we should be pleased that she can find him work to do. | | | Devoid of culture and unfamiliar with the gracious niceties of the many other forms of social intercourse, all he wants out of life is to swim north and spawn. | | | So if any woman wants to give Mr Spermatozoon a home, let's not begrudge her generosity. |
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http://www.greenleft.org.au/back/1997/262/262p20b.htm
(553 words)
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| | PAU 2003 |
| | The anterior extremity of the spermatozoon bears a helicoidal crested body approximately 100 nm thick. | | | The mature spermatozoon of P. torulosus differs from that of other Proteocephalus species in the presence of a single crested body and in the morphology of its posterior end. | | | Anotace: The fine structure of the mature spermatozoon of the proteocephalidean tapeworm Proteocephalus torulosus was studied by transmission electron microscopy for the first time. |
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http://www.iach.cz/knav/PAU03.HTM
(9226 words)
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| | ABC Online Forum |
| | You thought they were smaller than 56 micron? | | | Why, for example, do human males typically ejaculate over 200 million tiny gametes to fertilize just one egg? | | | During our recent trip to Las Cruces we discovered a huge spermatozoa which measured 13mm in length which is one of the longest sperm known, certainly for Lepidoptera. |
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http://www2b.abc.net.au/science/scribblygum/newposts/35/topic35802.shtm
(382 words)
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| | Clipart of Human egg seconds after fertilization by a spermatozoon. Male pronucleus not yet formed. - Search Clip Art ... |
| | This image / clip is not available for individual purchase. | | | Clipart of Human egg seconds after fertilization by a spermatozoon. | | | after, conceive, egg, fallopian, fertilization, formed, human, immediately, implantation, male, migration, not, ova, oviduct, ovum, pronucleus, seconds, sperm, spermatid, spermatozoa, spermatozoon, tube, uterine, yet, zygote, illustration, illustrations, clip art, clipart, picture, pictures, graphic, graphics, drawing, drawings, artwork, royalty free |
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http://www.fotosearch.com/LIF126/3d605001
(240 words)
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| | Research On Testis Function |
| | The objective of our research is to identify and characterize novel membrane and cytoskeletal proteins of plasma membrane specializations. | | | Cesario MM, Bartles JR 1994 Compartmentalization, processing and redistribution of the plasma membrane protein CE9 on rodent spermatozoa: relationship of the annulus to domain boundaries in the plasma membrane of the tail. | | | We are particularly interested in enzymes and proteins that appear during mammalian spermatogenesis and are unique to the spermatozoon. |
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http://www.northwestern.edu/center-for-reproductive-science/research/testisfunctuion.htm
(1040 words)
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| | Sperm Transmission Electron Micrograph |
| | At the right is the pseudopod, which the cell uses to crawl (see the video of a crawling spermatozoon). | | | his is a cross section through a mature sperm cell, or spermatozoon, from C. | | | To examine the surface features of a sperm, you can look at a scanning electron micrograph. |
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http://www.mcb.arizona.edu/wardlab/spermtem.html
(121 words)
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