Amafomu okukhiqiza izinto eziphilayo. Ithebula lezinhlobo zokukhiqiza

Ikhono lezidalwa eziphilayo zokuzikhiqiza zibizwa ngokuthi ukuphindaphinda. Kulokhu, izakhi zofuzo zidluliselwa enzalweni, futhi izimfanelo zomzali zizovela ngendlela ehlukile kwindodakazi entsha esanda kuvela.

Izinhlobo zokukhiqiza inzalo

Ososayensi bahlukanisa izinhlobo ezimbili eziyinhloko zokukhiqiza izinto eziphilayo. Kungaba ngokocansi noma isisulu. Esikhathini sokuqala, ukukhiqizwa kwenzalo kudinga abantu ababili, futhi okwesibili, kuyodwa okudingekayo.

Nge-reproduction asexual, isilwane esisha sitholakala kumaseli angama-somatic. Emvelweni, kunezindlela eziningana zokukhiqiza ngaphandle kokubamba iqhaza kwezitho zangasese. Lezi zihlanganisa ukukhiqizwa kwezitshalo, ukuhluma, ukuhlukaniswa, ukuhlunga, ukuhlukaniswa, ukukhonsa.

Ngesikhathi sokukhiqizwa ngokocansi, izilwane ezintsha zivela njengomphumela we-fusion yamaseli ekhethelo obulilili abizwa ngokuthi i-gametes, nokubunjwa okulandelayo kwe-zygote. Le ndlela iqhubeka kakhulu kune-asexual.

Ukuqhathaniswa kwezinzuzo

Kumele kuqashelwe ukuthi izindlela zombili zokukhiqiza inzalo zinemfanelo yazo. Ngokwesibonelo, izazi zezinto eziphilayo zihlukanisa izinzuzo ezilandelayo zokukhiqizwa kwe-asexual:

• Ikhono lokuzala inani elibalulekile labantu;
• Inzalo ifana nomzimba womzali yizo zonke izimpawu.

Le ndlela yokukhiqiza abantu abasha yenza kube lula ukuthola inzalo eningi. Lokhu kuzuzisa izinhlobo ezihlala ezimweni ezihlala njalo. Kuyinto yokukhiqiza okusheshayo, okuningi futhi okunembile kwamakhophi omzimba womama okusho ukukhiqizwa kwe-asexual. Le ndlela yokukhiqiza inzalo isetshenziswa yizo zombili izitshalo kanye nama-protozoans.

Kodwa ukukhiqizwa ngokobulili kuyisici sezinto eziningi eziphilayo. Iyakwazi ukuqinisekisa ukuhlukahluka kofuzo lwenzalo etholakalayo. Yilokho okubavumela ukuba bavumelane ngokushesha nezimo zokuphila eziguqukayo. Phela, ngesikhathi kwakhiwa isilwane esisha, inhlanganisela yezakhi zofuzo zabazali zenzeka.

Izinhlobo zokukhiqizwa kwe-asexual yenzalo

Kunezindlela eziningana zokuthola indodakazi ephilayo ngaphandle kokubandakanyeka kwamaseli wesondo. Zonke zifundiswa yi-biology. Ukukhiqizwa, izinhlobo zezinto eziphilayo ezinganeni ezingenalo ushintsho nhlobo, zingafezwa ngokuhlukanisa amaseli owodwa noma ngaphezulu.

Esikhathini sokuqala, amafomu alandelayo ayahluka:

• Ukuhlukaniswa kwamaseli angashadile noma amaningi (schizogony);
• Ukwakheka kwe-Spore;
• Ukubheka ama-unicellular.

Uma uhlukanisa iqembu lamaseli, ukuhlukaniswa kwenziwa kanje:

• Ukuhlukaniswa;
• Ukusetshenziswa kwemvelo eminingi (isb. I-hydra).

Ngayinye yalezi zinhlobo zokukhiqiza asexual inezici zayo.

Amafomu okukhiqiza

Inketho elula kakhulu ukuhlukaniswa. Kuyisici sezinto eziningi ezilula. Izibonelo zokukhiqizwa kwe-asexual nge-fission kanambambili: i-amoeba, i-infusoria-shoe, i- euglena eluhlaza.

Ukwakheka kwe-Spore kukholelwa kakhulu. Kuyisici cishe cishe zonke izitshalo, isikhunta, ezinye ze-protozoa nezinhlobo ze-prokaryotic (isibonelo, amabhaktheriya noma i-algae eluhlaza okwesibhakabhaka).

Ezinombalwa eziningana ze-unicellular and multicellular , uhlobo lokukhiqiza olufana nokuhluma kwenzeka. Lokhu kuyindlela elandelayo: isikhukhula sivela emzimbeni womama, okwandisa usayizi. Khona-ke kukhona ama-rudiments azo zonke izitho. Uma inqubo isuqedile, kuvele ukuvalwa. Le ndlela yokukhiqiza isebenzisa ama-coelenterates (i-hydra), i-unicellular (imvubelo, ezinye izinhlobo ze-infusoria).

Kodwa kunezinye izibonelo zokukhiqizwa kwe-asexual yezinto eziphilayo. Ngakho-ke, ungakhohlwa ngokuhlukaniswa. Kule nqubo, umzali uhlukaniswe izingxenye eziningana. Kuzo zonke izilwane zakhiwa. Isibonelo, i-filamentous alga spirogyra ingadliwa noma yikuphi. Ezingxenyeni ezimbili esikhathini esizayo kuyoba yizilwane ezimbili ezintsha.

Izitshalo zibhekene nokukhiqizwa kwezitshalo. Ngokomgomo wezinqubo, awufani nokuhluma noma ukuhlukaniswa. Isitshalo singakha izakhiwo ezikhethekile ezidingekayo zokukhiqiza. Futhi, ukubonakala kwengane yengane kungenzeka ngenxenye yomzimba womama.

Ukukhiqiza ngokocansi

Izidalwa eziningi eziphilayo ziveza kabusha izinto ezifanayo ngokuxuba izinto eziphilayo zofuzo. Ngenxa yalokhu, ama-gametes amabili ahlangene, futhi ngenxa yalokho i-zygote ye-diploid isungulwa. Esikhathini sokuthuthukiswa, isidalwa esisha esiphelele sitholakala kuyo. Izinhlobo zobulili zokukhiqiza izidalwa ziyingqayizivele kwezinye izitshalo zezimbali, ezilwaneni eziningi futhi, nakanjani, kubantu.

AmaGametti azinhlobo ezimbili - owesilisa nowesifazane. Uma izinhlobo ze-dioecious, ke uhlobo ngalunye lweseli lukhiqizwa ngabesilisa nabesifazane, ngokulandelana. Ezinye izinto eziphilayo ziyakwazi ukukhiqiza kokubili izinhlobo ze-gametes ngokuzimela. Kulesi simo, kuthiwa yi-hermaphrodites.

Ukukhiqizwa kocansi okungafani lapho i-gametes engabambi iqhaza nayo ingenzeka. Lezi yizinhlobo ezinjalo njenge-conjugation, gametangiogamy, i-apogamy, i-nog.

Inqubo yokukhiqiza

Zonke izidalwa zakhiwa ngamaseli. Ukukhula kwabo, ukuthuthukiswa kungenzeka ngenxa yokuthi ziphindaphindiwe. Enkonzweni yokuphila, amanye amangqamuzana aguga futhi afe. Bashintshwa abanye. Indlela kuphela yokuthola amangqamuzana amasha ahlukanise izimbangi zabo. Lokhu kuyindlela ebalulekile kuzo zonke izinto eziphilayo. Ngokwesibonelo, emzimbeni womuntu, izigidi eziningana zalezi zakhiwo zakhiwe zihlukaniswe njalo ngomzuzwana.

Izazi ze-biologist ziye zachaza izindlela ezintathu zokwanda kwamaseli. Ukuhlukaniswa okuqondile kuthiwa i-amitosis, engaqondile - mitosis, ukunciphisa - i-meiosis. Kungakhathaliseki uhlobo lokukhiqizwa kwezinto eziphilayo, kuzo zonke lezi zinqubo zenzeka.

I-Amytosis ne-mitosis

Indlela encane engavamile futhi engafundiwe yokuhlukaniswa kweseli i-amitosis. Kule nqubo, umgogodla uhlukaniswa yi-constriction. Ngesikhathi esifanayo, akunakwenzeka ukuqinisekisa ukuthi ukusatshalaliswa kwezinto ezibonakalayo. Iseli, elihlukaniswe yi-amitosis, ezimweni eziningi ngeke liqhubeke nokufaka umjikelezo ovamile we-mitosis. Ngakho-ke, kubhekwe njengesijeziso sokushabalala.

Indlela yokukhiqiza yama-eukaryotic amangqamuzana jikelele yi-mitosis. Ezingqamuzaneni zesilwane sidlula, njengombuso, ihora. Ungakhathaleli ukubaluleka kwezinto eziphilayo zokukhiqiza, ngoba kubonga kuye ukuthi ukuthuthukiswa nokukhula kwazo zonke izilwane kuqinisekiswa.

Izigaba ze-mitosis

Ukulandelana kwazo zonke izinqubo ezenzeka phakathi nokwakhiwa kwamaseli amasha kuthiwa umjikelezo weseli. Iqukethe izigaba ezintathu: i-interphase, i-mitosis, i-cytokinesis. Ubude bomjikelezo buxhomeke kuzo zombili izinhlobo zamaseli nezici zangaphandle. Ukushisa, ukutholakala kwezakhi, izithonya ze-oxygen. Isibonelo, ku-epithelium yamathumbu kwakhiwa kwamangqamuzana amasha njalo ngemizuzu engu-8-10, kuma-bacteria - njalo ngemizuzu engu-20.

Inqubo iqala nge-interphase. Ngalesi sikhathi, kunezinqubo zokukhula okujulile. Izinto ezikhuthaza ukukhula kweseli nokugcwaliseka kwayo yonke imisebenzi yayo zithuthukiswa. Phakathi ne-interphase, ukuphindaphinda kwe-DNA kwenzeka.

Ngokuqondile ngesikhathi se-mitosis , i-nucleus ihlukanisa. I-Chromatides phakathi nale nqubo ihlukaniswe nomunye futhi isatshaniswa kabusha phakathi kwamaseli amantombazane akhiwe ngendlela yama-chromosomes.

Inqubo, lapho ihlukanisa phakathi kwezinhlaka ezintsha ze-cytoplasmic, ibizwa nge-cytokinesis.

Phakathi nama-mitosis, amangqamuzana akhiwa lapho ulwazi oluzuzwa khona lufana ngokuphelele nomzimba womama. Phakathi nale nqubo, inani lama-chromosomes kabili.

I-Meiosis

Ngalendlela yokuhlukaniswa kweseli, inani lama-chromosomes liyingxenye eyodwa. Ngakho, ukukhiqizwa kwezilwane kanye ne-sporogenesis ezitshalweni kuqinisekiswa. Ngesikhathi se-meiosis, kuhlukaniswa izigaba ezimbili ezilandelanayo, futhi zilandelwa ukuphindaphinda okukodwa kwe-DNA.

Zonke izinto ezidingekayo kulezi zinqubo zigcinwa ngesikhathi sesigaba sokuqala - i-interphase. Isigaba ngasinye sokuhlukaniswa sinezikhathi ezine: i-prophase, metaphase, i-anaphase ne-telophase. Izigaba ezifanayo nazo zenzeka nge-mitosis, kodwa zonke izinqubo zinezici zayo ezikhethekile.

I-meiosis yokuqala yi-division cell, lapho inani lama-chromosomes linciphisa ngesici se-2. Ukusuka kokukodwa kwe-diploid ukwakheka kwama-haploid amabili. Ngalesi sikhathi, izinqubo zokuvuthwa kwe-DNA zenzeke, kuhlanganiswa ukuhlukana kokuhlukaniswa. Ngaphezu kwalokho, i-prophase ihlanganisa i-chromosomes ene-homologous. Ama-pair aphelile adala i-bivalent. Kwezinye izindawo, ama-chromatids awela. Le nqubo ibizwa ngokuthi ukuwela.

Isigaba sokugcina yilokho okuthiwa i-meiosis yesibili. Lesi sigaba, lapho amaseli aneqoqo lama-haproid lama-chromosomes ahlanganiswa ne-chromatid eyodwa. Ngenxa yezinqubo ezichazwe, amangqamuzana angu-4 avela ekutholeni kwe-diploid eyodwa (i-oogonia noma i-spermatogonia).

Incazelo yezinto eziphilayo ze-meiosis yilapho ukwakhiwa kwamangqamuzana okuqinisekisa ukukhiqizwa ngokocansi kwezilwane noma i-sporulation ezilwaneni eziphakeme. Yile ndlela yokukhiqiza okuqinisekisa ukugcinwa kokugcina kwezakhi zofuzo.

Izici zokukhiqiza ngokocansi nokusekelwa kwezinto eziphilayo

Kuye ngokuthi amangqamuzana ahlukaniswe kanjani inzalo, izinhlobo ezahlukene zale nqubo ziyahlukahluka. Ngokwehlukana, kufanele kuqashelwe ukuthi ukusinda kwezinhlobo eziningi eziphilayo endaweni eguqukayo kubangelwa ukuthi bangakwazi ukuhlanganisa izindlela ezahlukene zokukhiqiza.

Yiqiniso, ukukhiqizwa ngokocansi nokusekelwa ngokobulili kwalezi zinhlobo ezihlukile kakhulu. Itafula lezinhlobo zokukhiqiza kuzosiza ukuthi uqonde ukuthi yimiphi umehluko omkhulu.

Kusobala ukuthi izinhlobo zobulili zokukhiqiza izinto eziphilayo ziphelele kakhulu. Kodwa indlela yokuziphatha ngokungenasici iqinisekisa ukukhiqizwa okusheshayo kwenani elikhulu lenzalo. Ekukhiqizeni ngokocansi inamba yendodakazi yezinto eziphilayo ayikhuli kakhulu.