AmaGamethi amangqamuzana okuzala abizwa ngokuthi isidoda emadodeni neqanda esifazane. Zitholakala kwizindlala zocansi, ezibizwa nangokuthi ama-gonads. Ama-gonads kwabesilisa angama-testes kanti kwabesifazane angama-ovari. Sikhuluma "ngegemethi", igama lowesilisa.

Igama elithi "gamete" laqanjwa ngamagama asendulo esiGriki, "γαμ? Της ”, ama-gamet kanye ne-“ γαμ? Τις ”, ama-gametes, abhekisa endodeni nakwinkosikazi ngokulandelana.

AmaGamethi angamaseli we-haploid, okungukuthi, aqukethe iqoqo eliphelele lama-chromosomes ethu, kwikhophi elilodwa ngalinye.

Kwabesifazane

Ama-gametes abesifazane, abizwa nge-ova, enziwa ngama-ovari. Sinezimbili, esisodwa kwesokunxele nesinye kwesokudla. Amaqanda enza iqanda elilodwa ngenyanga. Leli qanda line-nucleus ezungezwe yi-cytoplasm, eboshwe ulwelwesi. Ngakho-ke iqanda liyiseli.

Lawa maseli okuzala, anesilinganiso esingu-0,1 mm ububanzi, angama-haploid. Banekhophi eyodwa kuphela ye-chromosome ngayinye, ngakolunye uhlangothi kuseli le-diploid, eliqukethe ama-homolog amabili e-chromosome ngayinye. Ziqukethe ama-chromosomes angama-22 e-autosome + 1 chromosome sex). Ama-gametes abesifazane enziwa ngesikhathi se-oogenesis, umjikelezo wama-ovari, isikhathi esiphakathi kwezikhathi zokuya esikhathini.

Ngaphambi kokuthomba, owesifazane unalokho okubizwa ngokuthi ama-ovarian follicles. Kuyinhlanganisela yamaseli ayindilinga kuma-ovari, aqukethe lokho okubizwa nge-oocyte, (iqanda elingakahleleki) elikhishwa ngesikhathi sokukhulelwa kweqanda.

Kungokuthomba kuphela lapho ama-follicles enza ukuvuthwa kwawo kudingekile nge-ovulation, bese ekhula ngosayizi. Amaqanda abe esebenza njalo bese kuthi ngemuva kwalokho akhiqize iqanda.

Ngakho-ke, njalo ngenyanga, i-ovarian follicle iyakhula, ku-ovary eyodwa noma kwenye, ngaphambi kokukhipha iqanda layo: bese sikhuluma nge-ovulation. Lo mkhuba, ophindaphindwa njalo ngenyanga, lapho kungekho ukuvundiswa, ngakho-ke ujikeleza, njengokuya esikhathini.

Iqanda aligudluki futhi liwugemethi lomanyolo. Uma kungazange kube nokukhulelwa, iqanda elikhishwe yi-ovary liyamunzwa ngephini le-proboscis futhi liyadonswa. Idlula ngesibeletho bese isuswa ngumuntu wesitho sangasese.

Ngesikhathi sokuphila kwakhe, owesifazane ukhiqiza inani elilinganiselwe lamaqanda, azungeze ama-400. Ukukhiqizwa kwamaqanda, kanye nezikhathi ziyeka eminyakeni yobudala engama-50, lesi simo sibizwa ngokuthi ukunqamuka kokuya esikhathini.

Kubantu

Ama-gametes abesilisa ngamanye amagama i-spermatozoa amangqamuzana angomahamba nendlwana angaphezulu kwama-micrometer ayi-60 (0.06 mm) ubude, angama-micrometer ayi-5 kuphela ekhanda.

Lezi zidoda, ezimise okonwabu bexoxo, zakhiwe izingxenye ezintathu: ikhanda, ingxenye emaphakathi nomsila. Inhloko emise okusaqanda iqukethe i-nucleus yona uqobo ebamba ama-chromosomes. Angama-chromosomes angama-23 abizwa ngama-autosomes + 1 chromosome aqondene nokufakwa amakhodi kwezocansi, okusho ukuthi okunquma ubulili bomuntu, owesilisa noma besifazane.

Ucezu oluphakathi luqukethe i-mitochondria nezakhi zomzimba ezivumela isidoda ukuba sihambehamba. Ekugcineni, isidoda sinomsila omude, obizwa nge-flagellum, ozosivumela ukuthi sizithundezele ngendlela ende yesibeletho sowesifazane ukuze sifinyelele esibelethweni bese sisifaka umquba.

Emadodeni, ukukhiqizwa kwesidoda, okwaziwa nge-spermatogenesis, kuqala ngesikhathi sokuthomba, ngesikhathi sobusha futhi kuyaqhubeka kuze kube sekufeni kwabo. Umjikelezo we-spermatogenesis uhlala ngokwesilinganiso sezinsuku ezingama-64, ngakho-ke kuthatha cishe izinyanga ezimbili nohhafu ukuthi amasende enze isidoda. Futhi amasende akwenze ngokuqhubekayo. Yize umkhiqizo ungaphansi kokuhlukahluka, umkhiqizo ojwayelekile uthathwa njengesidoda esiyizigidi eziyi-100 ngosuku.

Amasende akhiqiza isidoda, kodwa futhi noketshezi lomsoco olukhiqizwa ama-vesicles wesilisa kanye ne-prostate. Le ngxube yakha isidoda. Yenziwe ngo-90% uketshezi olunomsoco kanye no-10% wesidoda.

AmaGamethi amangqamuzana akhethekile umsebenzi wawo ukuqinisekisa ukukhiqizwa kabusha kocansi. Ukuze ukukhulelwa kwenzeke, isidoda ngakho-ke kufanele sihlangane neqanda futhi sihlangane naso. Isidoda esisodwa sivame ukwamukelwa iqanda, esivala ngokuzenzakalela ngokushesha nje lapho selingene endleleni yezinye.

Ngesikhathi sobudlelwano bezocansi, bangahlangana nabadlali bamageyimu wobulili obuhlukile bese umuntu ekhuluma-ke ngokukhulelwa, okungahle kukhiqize umuntu omusha.

Kunamacala amaningi lapho womabili owesilisa nowesifazane ama-gametes angabonisa ukungajwayelekile. Kuphakathi kokukhiqizwa kwabo, ukungabikho noma ukunganele kwe-spermatozoa, noma i-ova yokukhulelwa. Isidoda asiqinile ngokwanele ukufinyelela eqandeni, sibeka iqanda endaweni engafanele.

Kukhona nokungajwayelekile kwezakhi zofuzo, okubandakanya ukungalungi ngokuzayo noma isifo sofuzo lombungu, lokhu kwenzeka ngeTrisomy 21. Imvamisa umbungu awuthwalwa ngumzimba wowesifazane othola ukungajwayelekile.

Ukuhlolwa kwenziwa ngezigaba ezihlukene zokukhulelwa ukuvikela ubungozi bokungajwayelekile kofuzo.

Umnikelo kaGamete uthinta imibhangqwana yobudala bokubeletha okufanele ifune ukuzala okusizwa ngokwelashwa, kungaba ngenxa yokuthi omunye wabashadikazi uphethwe yinyumba etholakala ngokwelashwa, noma ngoba kunengozi yokudlulisela isifo esibi kakhulu enganeni noma komunye wabashadikazi.

Njengayo yonke eminye iminikelo yezakhi nemikhiqizo yomzimba womuntu, ukunikela kwama-gametes kuyisenzo sobumbano, esibuswa izimiso eziyinhloko zomthetho we-bioethics: ukungaziwa, ukukhululeka kanye nemvume.

Isibalo semibhangqwana elinde umnikelo wamageyimu nokuntuleka kweminikelo singokoqobo impela. Inani lemibhangqwana ebhaliswe ohlwini lokulinda lwezikhungo ezigunyaziwe liyanda minyaka yonke. Uhlelo lokusebenza lwangqongqoshe lwango-2017-2021 lokuzala lubeka phambili ekuthuthukisweni komnikelo we-gamete ukuze kuthuthukiswe ukuzimela kukazwelonke.