Imfundiso Evela Ku-Prokaryotic Kuya Ku-Eukaryotic: Ukuguquka Kobunzima Beselula
I-Pendahuluan
Ukuvela kokuphila eMhlabeni kungenye yezimfihlakalo ezithakazelisa kakhulu eziye zaheha ososayensi amakhulu eminyaka. Amaqembu amabili amakhulu ezinto eziphilayo, ama-prokaryotes nama-eukaryotes, amelela esinye sezinyathelo ezibaluleke kakhulu zokuvela kwemvelo. Ama-prokaryotes, afaka phakathi amabhaktheriya nama-archaea, ayizinto eziphilayo ezilula, ezineseli elilodwa eziye zaba khona izigidigidi zeminyaka. Ngokuphambene nalokho, ama-eukaryotes—afaka phakathi ama-protists, isikhunta, izitshalo, nezilwane—anezingqamuzana eziyinkimbinkimbi ngokwesakhiwo. Kodwa-ke, indlela ukuguquka kusuka kumaseli alula e-prokaryotic kuya kumaseli ayinkimbinkimbi e-eukaryotic okwenzeka ngayo isalokhu kuyisihloko socwaningo olunzulu nempikiswano. Lesi sihloko sizohlola imibono eyinhloko echaza ukuvela kusuka kuma-prokaryotes kuya kuma-eukaryotes.
Umsuka Wokuphila Kwamaselula
Eminyakeni eyizigidigidi edlule, uMhlaba wawuyindawo ehluke kakhulu kunanamuhla. Umkhathi wawo wawuntula umoya-mpilo, futhi impilo yamangqamuzana yayingakatholakali. Ukuphila kokuqala kungenzeka ukuthi kwavela ngesimo samangqamuzana e-prokaryotic cishe eminyakeni eyizigidigidi ezingu-3,5 kuya kweziyi-4 edlule. Lawa ma-prokaryote okhokho bazo zonke izinto eziphilayo ezaziwayo namuhla. Achuma ezimweni zemvelo ezimbi kakhulu, ebonisa ukuguquguquka okumangalisayo. Kodwa-ke, ukuguquka kusuka ezintweni eziphilayo ze-prokaryotic ezilula, ezineseli elilodwa kuya ezintweni eziphilayo ze-eukaryotic eziyinkimbinkimbi kwakudinga izinguquko ezinkulu esakhiweni kanye nomsebenzi wamangqamuzana.
I-Endosymbiosis I-Hypothesis
Enye yezinkolelo-mbono ezamukelwa kabanzi mayelana nokuvela kwamaseli e-eukaryotic yi-endosymbiotic hypothesis, eyahlongozwa okokuqala ngusosayensi waseMelika uLynn Margulis ngo-1967. Ngokwalo mbono, ama-organelle abalulekile kumaseli e-eukaryotic, njenge-mitochondria nama-chloroplast, aqala njengebhaktheriya ye-prokaryotic ephilayo ekhululekile eyakha ubudlelwano be-symbiotic neseli elikhulu, lokuqala lomnikazi.
1. I-Mitochondria: Kukholelwa ukuthi okhokho bokuqala bamaseli e-eukaryotic babegcwele amabhaktheriya e-aerobic, ayekwazi ukusebenzisa umoya-mpilo ukukhiqiza amandla ngendlela ephumelelayo ngokuphefumula. Esikhundleni sokugaya lawa mabhaktheriya, iseli eliyibamba lasungula ubuhlobo obuzuzisayo. Amabhaktheriya e-aerobic ahlinzeka ngomthombo wamandla osebenza kahle, kuyilapho iseli eliyibamba lihlinzeka ngokuvikelwa kanye nezakhamzimba. Ngokuhamba kwesikhathi, lawa mabhaktheriya ahlanganisiwe aguqukela kuma-mitochondria anamuhla.
2. Ama-chloroplast: Inqubo efanayo iyenzeka kuma-chloroplast, atholakala kumaseli ezitshalo kanye nama-algal. Kukholelwa ukuthi amaseli e-eukaryotic asendulo ayegubha amabhaktheriya e-photosynthetic njenge-cyanobacteria. Lokhu kwanika umnikazi we-eukaryotic ithuba le-photosynthesis, okwawavumela ukuthi akhiqize ukudla ngokukhanya kwelanga, ekugcineni aguquke abe ama-chloroplast.
Ubufakazi balo mbono buhlanganisa ukufana phakathi kwe-mitochondria nama-chloroplast kanye namabhaktheriya, njengokuba khona kwe-DNA eyindilinga, ama-ribosome afana nama-ribosome amabhaktheriya, kanye nekhono lokuzihlukanisa ngokuzimela ngaphakathi kweseli.
Ukuguqulwa Kwesakhiwo Nokusebenza
Ukuguquka kusuka kuma-prokaryotes kuya kuma-eukaryotes kwakungekona nje ukutholwa kwama-mitochondria nama-chloroplast. Kwakuhlanganisa nezinye izinguquko eziningi zesakhiwo nokusebenza, okuhlanganisa:
– Ukwakheka Kolwelwesi Lwenuzi: Esinye sezibonakaliso zamaseli e-eukaryotic ukuba khona kwe-nucleus ehlanganisa i-DNA yawo ngaphakathi kolwelwesi lwenuzi. Inkolelo-mbono evame kakhulu isikisela ukuthi ulwelwesi lwenuzi lwavela ngokungena kolwelwesi lwenuzi kuma-prokaryotes okuqala, ukuvikela izinto zofuzo nokulawula ukubonakaliswa kwezakhi zofuzo.
– Imishini Yezakhi Zofuzo Eyinkimbinkimbi Kakhulu: Ama-Eukaryote abonisa i-DNA ende futhi eyinkimbinkimbi kakhulu kune-prokaryotes, ahlelwe ngama-chromosome aqondile. Izici zokubhalwa kanye ne-RNA eyinkimbinkimbi kakhulu yokulawulwa kwezakhi zofuzo nazo zathuthuka.
– Uhlelo Lwe-Cytoskeletal: Ama-Eukaryote athuthukisa izakhiwo ze-cytoskeleton eziyinkimbinkimbi, okuvumela amaseli ukuthi alondoloze isimo sawo, ashukumise izinto ngaphakathi kweseli, futhi asebenzise ngisho ne-flagella kanye ne-cilia ukuze anyakaze.
– Ukwengezwa Kwamanye Ama-Organelle: Amanye ama-organelle ahlukahlukene, njenge-endoplasmic reticulum, i-Golgi apparatus, kanye ne-lysosomes, athuthukiswe ukuphatha ukucubungula amaprotheni kanye nokuthuthwa kanye neminye i-metabolism yamaseli ethuthukisiwe.
Indima Yokubambisana Ekuziphendukeleni Kwemvelo
I-Symbiosis, ubudlelwano bemvelo phakathi kwezinhlobo ezimbili ezihlala eduze, idlale indima ebalulekile ekuguqukeni kobunzima bamaseli. Ngaphakathi kohlaka lokuvela kusukela kuma-prokaryotes kuya kuma-eukaryotes, i-symbiosis ayihlinzekanga nje kuphela ngezinzuzo zokuzivumelanisa nezimo kodwa futhi yavula indlela yokusungula izinto ezintsha kanye nokuhlukahluka okubanzi kokuziphendukela kwemvelo. Ubambiswano lwe-Symbiosis alupheli ezingeni le-organelle; lungenza kube lula ukuvela kwemiphakathi emikhulu, luqhube ukuhlukahluka kokuphila okubonakala ezindaweni zemvelo zanamuhla.
Izinselele kanye nemibuzo evulekile
Nakuba i-endosymbiosis hypothesis yamukelwa kabanzi, kusenezinselele eziningi kanye nemibuzo engaphenduliwe, njenge:
– Izindlela Eziqondile: Ukuthi inqubo yokugwinya ephumelelayo kanye nokuzinza kwesikhathi eside kwe-symbiosis kwenzeka kanjani akukaqondakali ngokugcwele.
– Umsuka Wezinye I-Organelles: Nakuba i-mitochondria nama-chloroplast kucatshangelwa ukuthi avela kubhaktheriya wasendulo, umsuka wezinye i-organelles kumaseli e-eukaryotic usalokhu ungakacaci ngokuphelele.
– Ubufakazi Bezinto Eziphilayo: Izinto eziphilayo azibonisi imininingwane yokuguquka kwesinyathelo ngesinyathelo kusuka kumaseli e-prokaryotic kuya kumaseli e-eukaryotic, ngakho-ke ukuhlaziywa kwezakhi zofuzo kanye nezinto eziphilayo kuhlala kuwubufakazi obuyinhloko.
I-Penutup
Ukuguquka kusuka kumaseli e-prokaryotic kuya kumaseli e-eukaryotic kwakungenye yezinyathelo ezibaluleke kakhulu emlandweni wokuphila eMhlabeni. Ngenkathi ubunzima bokuziphendukela kwamangqamuzana busadinga ucwaningo olunzulu, imibono efana ne-endosymbiosis inikeza ukuqonda okubalulekile mayelana nokuguquguquka kwamangqamuzana okwenza impilo yathuthuka kakhulu. Ngokuthuthuka kwe-biology yama-molecule kanye nezakhi zofuzo, nsuku zonke sisondela ekuqondeni okujulile ukuthi le mpilo eyinkimbinkimbi yavela kanjani. Ukuphenya ngalolu shintsho akugcini nje ngokujulisa ukuqonda kwethu nge-biology eyisisekelo kodwa futhi nendlela impilo ngokwayo evumelana ngayo futhi ichuma ngayo lapho ibhekene nezinselele zemvelo ezishintsha njalo.
