Science Biology: poyambira - ndiko kuchimake kwa thupi nyama

Kodi Nsombayo, dziko umodzi wa achule, ndi Python, nkhunda, dolphin ndi munthu? Koyamba, palibe kotero chidwi kusiyana zamoyo wina ndi mnzake, onse mu maonekedwe ndi zoona, chimene iwo amadya ndi kumene moyo. Kodi iwo kufotokoza umodzi wa sayansi zamoyo?

The poyambira - thupi inakhazikitsidwa m'zaka embryogenesis pa anthu onsewa Dziko Lapansi. Kumene izo zinachokera? Kodi ntchito ya poyambira ndi zimene nyama amakumana chiyani? Pa funsolo linali tsopano, tidzapeza mayankho mu nkhani imeneyi. Zitsanzo zoperekedwa pansipa, zikusonyeza zosiyanasiyana chordates ndi udindo wawo kutsogolera mu m'chilengedwe achilengedwe.

Zochita za nyama zimene zili ofananira thupi

mbali zonse za dongosolo ndi kufufuta chibadidwe mitundu 42 zikwi zamoyo za thupi mtundu chordal, kuphunzira zamoyo. The poyambira - ndicho anatomical muyezo umene umakhala zamoyo izi mu gulu limodzi mwadongosolo. Ndi chingwe zotanuka, chomwe maselo connective minofu, amene amatithandiza thupi lonse. The notochord ili m'mbali thupi ndipo amalimbikira pa moyo mu mitundu ina, lotchedwa poyambira m'munsi. Iwo oimira jawless superclass: lamprey ndi hagfish. Mu nsomba cartilaginous, Nsombayi ndi cheza, mafupa lonse wapangidwa ndi minofu connective ndipo ali kapangidwe chomwecho monga poyambira pa. Iye, nayenso amasungidwa zamoyo izi moyo.

Kodi n'chiyani chinachitika ku kuonekera kwa mafupa mkati

ndi tanthauzo la poyambira chiyani? Biology amaona maonekedwe ake mu Amphioxus, ndi nyama ndiye zina zofunika aromorphosis. Zawachititsa kuti chitukuko cha dongosolo thandizo ndi chipembedzo chimene anatuluka mu nyama woyamba dziko. Zimenezi zinathandiza kuti tipeze ntchito pazipita mu kugonjetsa dziko ndi kukana, makamaka zochita zoipa za mphamvu yokoka ndi zina chokhwima zachilengedwe.

Mu yaikulu gulu nyama, anati peresenti chichereŵechereŵe m'malo ofananira timafupa dongosolo, chomwe ndi zinthu osseous - vertebrae. Zikuphatikizapo oimira magulu ambiri a nyama monga achule, zokwawa, mbalame ndi nyama. Kukhala m'madzi, ndi nsana, monga magulu Bony nsomba: carps, Clupeiformes, Perciformes, etc ...

Mu zamoyo zonse za magulu pamwamba ya nyama wotanganidwa malo lalikulu mu zomera za padziko lapansi. Izi imayendetsedwa ndi kafukufuku yemwe akugwira sayansi ndi zamoyo. The poyambira - ndi thupi, ndi kulola nyama kupikisana ndi invertebrates pomenyera kukhalapo.

choyamba chordates

maphunziro ambiri, asayansi anafuna kupeza nyama, amene dongosolo zikhoza kuganiziridwa kukhala ulalo pakati invertebrates ndipo inakhala. Mu pakati pa XIX m'ma Russian embryologist Kovalevsky anafotokoza embryonic chitukuko unremarkable wokhala Nyanja Black - Amphioxus mwachizolowezi.

Translucent cholengedwa mpaka masentimita 8, ndipo ngati nsomba popanda poyambira mutu anapitiriza moyo wake wonse. Amphioxus anatsimikizira mawonekedwe Transitional, kuli zimene kwa nthawi yaitali anafuna zamoyo. Poyambira - dongosolo, maonekedwe a kutsimikizira bwino chikhalidwe cha njira chisinthiko. Features ya kapangidwe embryonic (pamaso pa zigawo nyongolosi atatu) ndi ontogenesis Amphioxus anatsimikizira kopanda kuti makolo a chordates ndi zamoyo zopanda mafupa m'mimba.

Bookmark mafupa ofananira

Mapangidwe ndi poyambira kwa zamoyo zosiyanasiyana za yomweyo, ngakhale nthawi imeneyi imene izi zimachitika zosiyanasiyana. Mwachitsanzo, anthu embryonic connective chingwe limapezeka nthawi kale chitukuko embryonic, ndipo tsamba wake uli wachangu kuposera ya nsomba kapena inakhala ena. Kumbuyo chitsulo chogwira matayala mtima anapanga pansi chubu ubongo. Gawo chachikulu matumbo otchedwa hordomezodermalnym mafuta akufotokozera inakhala poyambira.

Biology ndiponso mwatsatanetsatane Medicine izuchyut njira zikuchitika mu gawo la gastrulation timaona kuphwanya chitukuko yoopsa, zomwe mwina zikuphatikizapo kuchepa viability, maonekedwe a kuvutika ndi imfa ya khanda. Kulephera njira Bookmark ziwalo ofananira: chubu ubongo, notochord, intestine - ndi owopsa kotero njira yachibadwa mimba mu trimester ndi zofunika kwambiri pa moyo wa mwana wosabadwa.

The zosiyanasiyana kufunika kwa mtundu chordwise

The oimira gulu la zamoyo ndi bwino ndinazolowera zinthu zosiyanasiyana zachilengedwe imene zolengedwa zonse za padziko lapansi niches zachilengedwe. Mu hydrosphere, m'nyumba oposa 20 zikwi. Nsomba mitundu imene amaonedwa chordates amakezana, pamwamba ndi akuya lithosphere ali wodzazidwa ndi chiwerengero chachikulu cha mitundu ya achule, zokwawa zam'madzi ndi dziko ndi chilengedwe mpweya anthu oposa 8 zikwi. Birds. Ndi mtundu wa poyambira ndi ndi anthu anthu amene umoyo wachibadidwe anasintha nkhope ya dziko lathuli.