Ukukhiqiza ngokocansi phakathi kwabameleli abaphezulu nabaphansi bezitshalo

Ukukhiqizwa yisici sezinto eziphilayo. Lekhono lokuzala lihlinzeka ukuqhubeka nokuqhubeka kokuphila. Eziphilayo ezinesimo sesakhiwo seselula, ukuhlukaniswa kuyisisekelo sokukhiqiza.

Ososayensi abahlukahlukene baye bahlongoza ukuhlukaniswa okuhlukene kwezinhlobo zokukhiqiza. Izinhlobo ezintathu zokukhiqiza zibhekwa njengeziyisisekelo : izitshalo ezomzimba, ubulili kanye nama-asexual.

Esikhathini esilandelayo, ukuthuthukiswa kwezinto eziphilayo kuvela esitokisini, hhayi ukuhlukaniswa ngokocansi. Ukukhiqiza izitshalo kuwuphawu lokuthuthukiswa kwemvelo evela emibungu eminingi, ngezinye izikhathi kunzima ukuhlukanisa.

Ukukhiqizwa kwezitshalo kwezocansi kuqala ngokubunjwa kwama- sex cells (gametes). Ukukhiqiza ngokwayo kuphelela ekuhlanganiseni kwe-gametes ibe yi-zygote. Le nqubo ibizwa ngokuthi ukukhulelwa futhi iqinisekisa ukudluliswa kwedatha yezofuzo kubazali kuya enzalweni.

Ama-Gametes akhiwa ezithombeni zobulili - i-gametangia. Abamele izitshalo, ezibhekene nokukhulelwa, babe ne-meiosis emjikelezweni wabo wokuthuthukiswa.

Ukukhiqiza ngokocansi akuyona into ejwayelekile ye- blue-green algae, amabhaktheriya. Le ndlela yokukhiqiza ayitholakali eziningana zefungi.

Izinhlobo zokukhiqiza ngokocansi kwabamele abancane bezitshalo zihlukile. Ngakho-ke, kwezinye izitshalo eziluhlaza, inqubo yokukhiqiza ingenzeka ngaphandle kokwakhiwa kwe-gametes. Kulesi simo, izinhlobo ezimbili ze-unicellular zihlanganisa.

Ukuhlanganiswa kwama-gametes ane-flagella kubizwa ngokuthi i-isogamy. Ukukhiqizwa ngokocansi okunjalo kuyisici samaningi amaningi.

Ama-unicellular algae (amanye ama-chlamydomonads, isibonelo) ngezinga elithile ngokwabo aphendukela ezithombeni zobulili, enza ama-gametes. Abameli abaningi be-gametangiae baba ngamaseli ahlukile, ahluke kwabanye, noma ama-gametangia akhiwa, anemibono ye-morphological (isibonelo, ectocarpus).

Kuzo zonke izilwane eziphilayo ezingenalutho zibhekene ne-heterothallism (ukwehlukana ngokocansi nokuphila ngokobulili). Kulesi simo, kwenzeka i-fusion ye-gametes ehlukahlukene yemvelo.

Kwamanye ama-algae, ukuhlanganiswa kuyisici: "ukugeleza" kwe-protoplast kusuka kwesinye iseli kuya kwesinye kwenzeka.

Ukuhlanganiswa kwama-gametes abe ne-flagella ehlukene kubizwa ngokuthi i-heterogamy. Ukuxhumeka kwe-gamete ye-female engavunyelwe (amaqanda) futhi ukuba ne-flagella (ngokuvamile kaningi) wesilisa omncane (insizwa) kuthiwa i-oogamy. Ukukhiqizwa ngokocansi okunjalo kuyisici sezinqwaba eziningi ezibomvu, ezibomvu, ezithinta izidakamizwa, izitshalo eziluhlaza, kanye nenamba encane yomkhuhlane.

Ukufaka umanyolo kule hologram, i-heterogamous, isogamous kanye ne-ooham emele abamele imifino yenziwa emanzini. Ezinhlobonhlobo zezitshalo ezinama-oogamous, inqubo ye-fusion kwenzeka ku-oogonia (i-gametangia yabesifazane). Bakhuthaza ngenkuthalo isidoda, bakhululwa emanzini. Umsebenzi, ngokusobala, ungenxa ye-chemotaxis. Kulesi simo, insimu yesibhakabhaka ebomvu (i-algae ebomvu) idluliselwa ngamanzi wamanje - ngokungahleliwe.

Izitshalo eziphakeme zinezici eziningi. Nokho, ukukhulelwa kwabo kwenzeka ngezindlela ezahlukene. Ukuze izitshalo eziphakeme, i- gametangia yama-multicellular ejwayelekile - i-archegonia (owesifazane) ne-antheridia (owesilisa). Ezingxenyeni zangaphandle zezitho zangasese, amangqamuzana ayinyumba. Esikhathini i-archegonium, amaqanda amaqanda akhiwa ngamunye, ku-antheridia, i-spermatozoa ivame ukubunjwa ngamanani amakhulu.

Ukukhiqizwa ngokocansi kwe-fern-like ne-bryophyte kwenzeka emanzini. I-Spermatozoa ishiya i-antheridia futhi ihambele e-archegonium. Kanti, ukulungele-ukucwilisa i-archegonia kudonsela i-spermatozoa nge-mucus exreted kusuka phezulu evelele. Ukuqhubekela phambili ngaphakathi kwe-mucus, i-spermatozoa isondela emaqanda, kodwa ihlangana nayo yodwa.