Zygote - iseli lokuqala ezintsha. Isiteji yentuthuko zygote

Iyunithi eziyisisekelo bonke ukuphila eMhlabeni kuseli. Kuyinto ukwakheka kwamaseli amasha evumela umzimba ukuze akhule ngendlela. Zokuziphilisa kanye nesakhiwo zalamaqembu.I kunzima kakhulu futhi kuncike imininingwane yalolu uya khona.

Ukuvela kwegama elithi "zygote"

Ukuvela "zygote" gama lihlanganisa inkulumo ukutuswa isazi-German Edward Strasburger, ngubani wanikezela ukuphila kwakhe ekutadisheni Cytology futhi chromosome imfundiso yokuziphendukela ufuzo. Nguye ngasekupheleni XIX leminyaka, kuqala wafinyelela esiphethweni ukuthi cell division ezikulesi simila, isilwane futhi umzimba womuntu owenziwe kahle cishe elilodwa futhi isikimu efanayo.

Zygote: yencazelo

Ubulili amaseli (gametes) enze imifanekiso, okungukuthi, ngenxa yobukhona babo emzimbeni ukukhiqizwa kabusha mhlawumbe ngokobulili. Female gamete - iqanda, amadoda - isidoda. gamete ngamunye haploid (owodwa) iqoqo chromosome.

Umqondo "ontogeny" kuhlanganisa wonke izigaba ukuthuthukiswa i umzimba kusukela uqala ukwenziwa kuze ukufa. Ekuqaleni kwalo - it is avundiswa, okungukuthi, Fusion isidoda neqanda, okuphumela ekwakhiweni of a zygote. Kuyinto ukwaziswa kwezakhi zofuzo kusuka bobabili abazali. Uyini zygote? Biology kunikeza incazelo eqondile leli qiniso. Sine ukubukeka eningiliziwe kweyesi-ke.

Ngakho, i-zygote - amaseli diploid, okuyinto akhiwa Fusion gametes. Diploidy okubangelwa ephelele (ezimbili) isethi wama-chromosomes, okulingana ethathwe gametes zoyise kwabakhulelwe. Ukuthuthukiswa kwe-zygote iqala ngokushesha ngemva inqubo kokukhulelwa, okuthiwa kokukhulelwa.

Cleavage we zygote

Lapho beqeda inqubo sokukhulelwa, iseli okuholela uthuthela kwesibeletho. Endleleni, isivele sekuqala ukwenzeka, kanye nokuthuthukiswa kwasani zygote. Lena inqubo eyinkimbinkimbi ehlanganisa izigaba eziningana.

Phakathi ngesikhathi sokukhulelwa kanye mitotic division lokuqala ubabonisa cishe 30 amahora. Lesi yisikhathi lapho isidumbu sowesifazane zonke izinqubo wokulungiselela, okuyizinto ezibalulekile ekuthuthukisweni ephilayo entsha. Vimbela ukwakhiwa obengeziwe umbungu kungenzeka ezahlukahlukene ezithinta isimo umzimba wesifazane. izici ezinjalo zihlanganisa chromosomal kuguquka, ngendlela engalungile ama kokuphila kukanina (utshwala, izidakamizwa, ukubhema), ukusetshenziswa kunemithi noma amaphilisi owaphuzayo, izifo ezinzima viral, njll

Kusukela zygote umbungu okhula. Isigaba sokuqala sale nqubo - kwasani. Leli akulona igama okungahleliwe. Ngemva phakathi ukwahlukana esiteji okungaxhunyiwe ku-intanethi weseli ukukhula, isb ngenxa ngamunye kubo ncamashi kumaseli isigamu wehlise ngosayizi futhi babe ezincane. Indodakazi amaseli ezakhiwe nokuqeda zygote, abizwa ngokuthi "blastomeres." Inqubo kwasani ihlala kuze kube ngomzuzu lapho ayakhekanga ombungu. Ngakho, singasho ukuthi umzimba womuntu ngenxa ngezigidigidi zamaRandi dollar Ukuhlukaniswa zygote.

Isigaba blastula futhi gastrulation

Blastomeres aqukethe izingqimba ezimbili. Kwangaphandle eseduze igobolondo esobala. Ibizwa ngokuthi trophoblast (izakhi leaf), kanye yangaphandle - embryoblast (embryonic leaf). Kancane kancane, ngesikhathi division okuphindaphindiwe phakathi izingqimba ezimbili kwakhiwa umgodi ngaphakathi okuyinto ekuqongeleleni uketshezi. Leli phuzu esigabeni blastula.

Lokuzaliswa embryoblast amaseli kuhambisana ukukhula odongeni ingaphakathi. Ngenxa yalokho, kukhona ukubukeka yesibili ungqimba embryoblast esiyingxenye isikhuphasha isitsha. Kanyekanye le nqubo, omningi walo embryoblast kwakhiwa lwegciwane fetus ziqoqwa kwenye izingongolo. Kuyinto kulesigaba umbungu ifinyelela kwesibeletho. Ngaphezu kwalokho kukhona ikhishwe kusukela ulwelwesi kanye yenzeka esobala.

Trophoblast kule nqubo linendima ebalulekile, ngoba amangqamuzana yayo, ukuba izakhiwo proteolytic, kwancibilika epithelium endaweni umbungu axube ulwelwesi kwesibeletho. Ngenxa yalokho, i-epithelium kuba mass lactescent.

isigaba zygote yentuthuko ngokushesha aphumelele nomunye. Blastula iguqulwe ukuze gastrula emele ibhaluni ezimbili ungqimba. Olwelwesini - kuyinto yi-ectoderm, ephansi - endoderm.

organogenesis

Zygote - iseli lokuqala ezintsha. Yonke iqoqo luyadingeka ukuze kube nokuphila zemizimba ekuqaleni kwakhiwa kusuka kubo. kakhulu Inqubo iziphathimandla zemfundo ngokuthi organogenesis. Ekuqaleni kwalo kuphawulwa ukwakheka ipuleti kwemizwa ukuthi kwenzeka yi-ectoderm ku amaphiko uhlangothi umbungu. kuphakama Eminye umklamo nezinye izitho futhi izinhlelo kwesikhumba futhi uqondiswe isimiso sezinzwa esiyinhloko (yi-ectoderm); wokugaya ukudla futhi umgudu wokuphefumula (kusukela endoderm); uhlelo zemisipha, kwegazi, izinhlelo excretory nekutala (kusukela mesoderm). Ngaphezu kwalokho, kuze kube ekuzalweni, lezi zinhlelo eyenziwa futhi ngcono.

ukuthuthukiswa kwe-embryonic

Le nkathi iqale kusukela ekuzalweni kuze kuqala nezingokomzwelo zokuthomba. Kuye ezingeni yenhlangano eziphilayo, kunezinhlobo ezimbili zama- yentuthuko sombungu.

1. ukuthuthukiswa okuqondile. Kulokhu, ingane izici zangaphakathi nezangaphandle efanayo nabazali babo. Umehluko e ubukhulu kanye nokungathuthuki kwezinye izitho. Kuyinto sici for izinyoni nezilwane ezincelisayo, kuhlanganise nabantu.
2. ukuthuthukiswa ongaqondile. Kulesi hlobo ukuthuthukiswa, ingane (isibungu) has umehluko eziningi nabazali babo. Akumangalisi amaxoxo kanye izinambuzane.

Zygote - yeseli amakhophi genotype abazali. Kodwa inqubo yentuthuko kwamaseli umbungu uqale kuhluke isakhiwo futhi wenze imisebenzi ehlukahlukene. Lokhu kungenxa yokuthi ezithile zofuzo ukusebenza kwamanye amaseli, kuyilapho abanye kwenye indawo. Ngakho, umzimba, kwakha isimiso esiyinkimbinkimbi kwesakhiwo, okuyinto esekelwe zygote.