Zygote - wikipedia Zygote For other uses, see Zygote ( disambiguation ). `` Fertilized egg '' redirects here. For the food product, see Balut ( egg ). Zygote ( cell ) Details Days 0 Precursor Gametes Gives rise to Morula Identifiers Code TE E2. 0.1. 2.0. 0.9 Anatomical terminology ( edit on Wikidata ) A zygote ( from Greek ζυγωτός zygōtos `` joined '' or `` yoked '', from ζυγοῦν zygoun `` to join '' or `` to yoke '' ), is a eukaryotic cell formed by a fertilization event between two gametes. The zygote 's genome is a combination of the DNA in each gamete, and contains all of the genetic information necessary to form a new individual. In multicellular organisms, the zygote is the earliest developmental stage. In single - celled organisms, the zygote can divide asexually by mitosis to produce identical offspring. Oscar Hertwig and Richard Hertwig made some of the first discoveries on animal zygote formation. Contents 1 Fungi 2 Plants 3 Humans 4 In other species 5 In protozoa 6 See also 7 References Fungi In fungi, the sexual fusion of haploid cells is called karyogamy. The result of karyogamy is a diploid cell called a zygote or zygospore. This cell may then enter meiosis or mitosis depending on the life cycle of the species. Plants In plants, the zygote may be polyploid if fertilization occurs between meiotically unreduced gametes. In land plants, the zygote is formed within a chamber called the archegonium. In seedless plants, the archegonium is usually flask - shaped, with a long hollow neck through which the sperm cell enters. As the zygote divides and grows, it does so inside the archegonium. Humans In human fertilization, a release ovum ( a haploid secondary oocyte with replicate chromosome copies ) and a haploid sperm cell ( male gamete ) -- combine to form a single 2n diploid cell called the zygote. Once the single sperm enters the oocyte, it completes the division of the second meiosis forming a haploid daughter with only 23 chromosomes, almost all of the cytoplasm, and the sperm in its own pronucleus. The other product of meiosis is the second polar body with only chromosomes but no ability to replicate or survive. In the fertilized daughter, DNA is then replicated in the two separate pronuclei derived from the sperm and ovum, making the zygote 's chromosome number temporarily 4n diploid. After approximately 30 hours from the time of fertilization, fusion of the pronuclei and immediate mitotic division produce two 2n diploid daughter cells called blastomeres. Between the stages of fertilization and implantation, the developing human is a preimplantation conceptus. There is some dispute about whether this conceptus should no longer be referred to as an embryo, but should now be referred to as an proembryo, which is terminology that traditionally has been used to refer to plant life. Some ethicist and legal scholars make the argument that it is incorrect to call the conceptus an embryo, because it will later differentiate into both intraembryonic and extraembryonic tissues, and can even split to produce multiple embryos ( identical twins ), while others have pointed out that, as so - called extraembryonic tissues are really parts of the embryo 's body that are no longer utilized after birth, much as milk teeth fall out after childhood, and as the process of the embryo splitting to form identical twins leaves the original intact, while generating a new embryo, rendering it no different from the process of cloning an adult human. However, the National Institutes of Health has made the determination that the traditional classification of pre-implantation embryo is still correct. After fertilization, the conceptus travels down the oviduct towards the uterus while continuing to divide mitotically without actually increasing in size, in a process called cleavage. After four divisions, the conceptus consists of 16 blastomeres, and it is known as the morula. Through the processes of compaction, cell division, and blastulation, the conceptus takes the form of the blastocyst by the fifth day of development, just as it approaches the site of implantation. When the blastocyst hatches from the zona pellucida, it can implant in the endometrial lining of the uterus and begin the embryonic stage of development. The human zygote has been genetically edited in experiments designed to cure inherited diseases. In other species A Chlamydomonas zygote that contains chloroplast DNA ( cpDNA ) from both parents, such cells generally are rare since normally cpDNA is inherited uniparental from the mt+ mating type parent. These rare biparental zygotes allowed mapping of chloroplast genes by recombination. In protozoa In the amoeba, reproduction occurs by cell division of the parent cell : first the nucleus of the parent divides into two and then the cell membrane also cleaves, becoming two `` daughter '' Amoebae. See also Proembryo References Jump up ^ `` English etymology of zygote ''. etymonline.com. Jump up ^ Blastomere Encyclopædia Britannica. Encyclopædia Britannica Online. Encyclopædia Britannica Inc., 2012. Web. 06 Feb. 2012. Jump up ^ Larsen 's Human Embryology. 4th Ed. Page 4. Jump up ^ Condic, Maureen L. ( 14 April 2014 ). `` Totipotency : What It Is And What It Is Not ''. Stem Cells and Development. Retrieved 15 January 2017. Jump up ^ ( 1 ) Jump up ^ O'Reilly, Deirdre. `` Fetal development ''. MedlinePlus Medical Encyclopedia ( 2007 - 10 - 19 ). Retrieved 2009 - 02 - 15. Jump up ^ Klossner, N. Jayne and Hatfield, Nancy. Introductory Maternity & Pediatric Nursing, p. 107 ( Lippincott Williams & Wilkins, 2006 ). Jump up ^ Neas, John F. `` Human Development '' Archived July 22, 2011, at the Wayback Machine... Embryology Atlas Jump up ^ Blackburn, Susan. Maternal, Fetal, & Neonatal Physiology, p. 80 ( Elsevier Health Sciences 2007 ). Jump up ^ Human zygote edited genetically Preceded by Oocyte + Sperm Stages of human development Zygote Succeeded by Embryo Human embryogenesis in the first three weeks Week 1 Fertilization Oocyte activation Zygote Cleavage Blastomere Morula Blastocoele Blastocyst Blastula Inner cell mass Trophoblast Week 2 ( Bilaminar ) Hypoblast Epiblast Week 3 ( Trilaminar ) Germ layers Archenteron / Primitive streak Primitive pit Primitive knot / Blastopore Primitive groove Gastrula Gastrulation Regional specification Embryonic disc Ectoderm Surface ectoderm Neuroectoderm Somatopleuric mesenchyme Neurulation Neural crest Endoderm Splanchnopleuric mesenchyme Mesoderm Axial mesoderm Paraxial Somite Somitomere Intermediate Lateral plate Intraembryonic coelom Splanchnopleuric mesenchyme Somatopleuric mesenchyme Retrieved from `` https://en.wikipedia.org/w/index.php?title=Zygote&oldid=800866967 '' Categories : Developmental biology Reproductive system Mammal female reproductive system Human female reproductive system Hidden categories : Webarchive template wayback links Medicine infobox template using GraySubject or GrayPage Talk Contents About Wikipedia Afrikaans Alemannisch Aragonés Azərbaycanca বাংলা Bân - lâm - gú Беларуская Беларуская ( тарашкевіца ) ‎ Български Bosanski Català Čeština Cymraeg Dansk Deutsch Eesti Ελληνικά Español Esperanto Euskara فارسی Gaeilge Galego 한국어 Հայերեն हिन्दी Hrvatski Ido Bahasa Indonesia Íslenska Italiano עברית ქართული Latina Latviešu Lietuvių Македонски മലയാളം Bahasa Melayu Nederlands 日本 語 Norsk Norsk nynorsk Occitan Oʻzbekcha / ўзбекча Polski Português Română Русский Scots Simple English Slovenčina Slovenščina Српски / srpski Srpskohrvatski / српскохрватски Suomi Svenska Tagalog தமிழ் ไทย Тоҷикӣ Türkçe Українська اردو 中文 Edit links This page was last edited on 16 September 2017, at 04 : 35. 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Question: when does the fertilized ovum divide after fusion
Answer: the zygote