Isayensi Biology: kuzithinta - uphakathi nendawo ngomzimba isilwane

What do ushaka, umhlaba iselesele, a Python, ijuba, ihlengethwa futhi indoda? Uma uthi nhlá, ayikho into ngakho yesiteleka umehluko izinto eziphilayo ukusuka kwesinye omunye, kokubili ababukeka eqinisweni, lokho akudlayo nalapho ukuphila. Bangakwenza kanjani ukuchaza ubunye isayensi biology?

Kuzithinta - umzimba imiswe phakathi embryogenesis kuzo zonke lezi zakhamuzi zasendulo Earth. Kusukela lapho-ke umsuka? Yiziphi imisebenzi kuzithinta nalokho izilwane ahlangana? On umbuzo kwaba manje, siyothola izimpendulo kulesi sihloko. Izibonelo enikezwa ngezansi, ukufanekisa ukuhlukahluka chordates kanye nendima yabo okuholela zemvelo.

Izici Zabantu Axial umzimba ezilwaneni ezinomgogodla ezinamehlo

Zonke izici isakhiwo nekusebenta umuntu azalwa nalo lokuhlaziya ayizinkulungwane 42 zezintaka eziphilayo nezidalwa okuqondene chordal uhlobo, ukutadisha biology. Kuzithinta - main nenqubo yokwakheka esihlanganisa la magciwane ukuze zibe yisikhungo esisodwa ehlelekile. Kuyinto intambo nokunwebeka, esakhiwa zezinzwa izicubu amaseli, esihlinzeka ukwesekwa wonke umzimba. I notochord itholakala kanye umzimba futhi iqhubeka kukho konke ukuphila kwezinye uhlobo, olubizwa ngokuthi kuzithinta aphansi. Ziyakwazi abameleli jawless superclass: lamprey futhi hagfish. Ngo izinhlanzi cartilaginous, oshaka imisebe, amathambo awo wonke umzimba yakhiwa sezicubu zezinzwa futhi ine isakhiwo efanayo kuzithinta. Yena, lilondolozwe la magciwane ukuphila.

Waba yini umphumela ukuvela lwamathambo yangaphakathi

Lisho ukuthini igama elithi ka kuzithinta? Biology uyazicabangela ukubukeka yakhe Amphioxus, bese nezinye izilwane aromorphosis ebalulekile. Uye waholela ukuthuthukiswa uhlelo lokweseka futhi ukunyakaza ukuthi kwavela izilwane eziphila ezweni kuqala. Lokhu kwavumela ukuba uthole inzuzo esiphezulu ekunqotshweni ezweni futhi sikwazi ukumelana, ikakhulukazi ithonya elibi amabutho gravity kanye nezinye izici zendawo ezimbi.

Ngo olubanzi iqembu isilwane, wathi yezilwane ezinomgogodla uqwanga indawo Axial Strand isakhiwo, okuyinto inezigaba osseous - amathambo. Lezi zihlanganisa abameleli amakilasi iningi izilwane zasezweni, ezifana eziphila emanzini nasezweni, ezihuquzelayo, izinyoni nezilwane ezincelisayo. Ukuze impilo yasemanzini, nokuba umgogodla, zihlanganisa amaqembu bony izinhlanzi: carps, Clupeiformes, Perciformes, njll ...

Ngo ukuvela zonke amaqembu ngenhla kwezilwane ukuba zazixake isikhundla ovelele kule nezilwane nazo kulo mhlaba. Lokhu kufakazelwa ucwaningo ebamba isayensi biology. Kuzithinta - iyona umzimba, avumele lezi zilwane ancintisane ezingenamgogodla emzabalazweni khona.

chordates Okokuqala

Izazi eziningi, ososayensi bafuna ukuthola isilwane, ogama isakhiwo ingathiwa njengoba isixhumanisi phakathi ezingenamgogodla futhi ezilwaneni ezinomgogodla. Ngo phakathi sesayensi yemibungu nokukhula kwayo Russian XIX leminyaka Kovalevsky wachaza embryonic ukuthuthukiswa owakhileyo zingezona ezibonakalayo we Black Sea - Amphioxus evamile.

Ayevumela isidalwa-8 cm, nanjengensimu engenamanzi izinhlanzi ngaphandle kuzithinta ikhanda agcinwayo kukho konke ukuphila kwakhe. Amphioxus ebonakaliswe ifomu zesikhashana, ukuba khona lapho i-biology ngakho eside wafuna. Chord - isakhiwo, ukubukeka okufakazela kahle ubunjalo indlela ukuziphendukela kwemvelo. Izici isakhiwo embryonic (khona izingqimba ezintathu igciwane) kanye ontogenesis Amphioxus waqinisekisa kucatshangwa ukuthi okhokho chordates kukhona eziphilayo abangenathuba skeleton yangaphakathi.

Bookmark lwamathambo Axial

Kumiswa kuzithinta kusuka eziphilayo ezahlukene imayelana abafanayo, nakuba ayengafani isikhawu lapho lokhu kwenzeka ziyahlukahluka. Ngokwesibonelo, abantu-embryonic intambo zezinzwa livela esikhathini ngaphambili yentuthuko embryonic, futhi ithebhu yawo ngokushesha ukwedlula ukuthi zezinhlanzi noma ezinye ezilwaneni ezinomgogodla. Umhlane oluvala amasondo nuclei esakhiwa ngaphansi neural tube. Of eyinhloko ingxenye emathunjini ngokuthi hordomezodermalnym neseleko eba ezilwaneni ezinomgogodla ezinamehlo kuzithinta.

Biology and Medicine ngokuningiliziwe izuchyut izinqubo ezenzeka esigabeni ka gastrulation owembula ukwephulwa wokukhula kwengane esiswini, okungase kuhilelani ukwehla ukusebenza, ukubukeka kahle kwezinso nokufa ombungu. Ukwehluleka izindlela ibhukumaka izitho Axial: neural tube, notochord, amathumbu - iyona ayingozi kakhulu, ngakho inkambo evamile yokukhulelwa e senyanga yokuqala ibaluleke kakhulu impilo umntwana ongakazalwa.

Ukuhlukahlukana futhi ukubaluleka uhlobo chordwise

Abameleli leli qembu elikhulu eziphilayo kahle ngakho ingashintshwa ukuze izici ezahlukene kwemvelo esasisentshonalanga zonke izidalwa niches emhlabeni semvelo. Esikhathini hydrosphere, abantu abangaphezu kuka-20 eziyinkulungwane. Fish izinhlobo zibhekwa chordates zasendulo impela, incwadi surface kanye we lithosphere ukujula zigcwele lenqwaba izinhlobo eziphila emanzini nasezweni, ezihuquzelayo nezilwane ezincelisayo, naphakathi umhlaba futhi emoyeni imvelo uhlalwe angaphezulu kwangu-8 ayizinkulungwane. Birds. Ngu uhlobo kuzithinta kuba kanye nabantu womuntu kabani zokuziphilisa ngokuyinhloko kwashintsha umlando we-iplanethi yethu.