Kimiyya Biology: tsirkiya - shi ne cibiyar da dabba jiki

Abin yi a shark, duniya toad, a Python, kurciya, dabbar dolfin kuma mutum? A duban farko, kome ne don haka daukan hankali bambanci kwayoyin daga juna, duka a bayyanar da a gaskiya, da abin da suka ci da kuma inda ya zauna. Yaya za su iya bayyana dayantakan kimiyya da ilmin halitta?

A tsirkiya - a jiki kafa a lokacin embryogenesis a duk wadannan mazaunan duniya. Daga wanda shi ya samo asali? Mene ne ayyuka na tsirkiya, kuma abin da dabbobi ta gana? A cikin tambaya ya yanzu, za mu sami amsoshin a cikin wannan labarin. A misalai bayar a kasa, ya nuna bambancin da chordates da su jagorancinsa halitta al'amarin.

Halaye na axial jiki vertabrate

Duk da siffofin da tsarin da aiki muhimmi zuwa 42 dubu jinsunan halittu masu rai na zuwa chordal type, karatu ilmin halitta. A tsirkiya - shi ne babban ilimin Halittar Jiki sharudda cewa haɗa kan bangaskiya wadannan kwayoyin a cikin wani aure na din-din-din naúrar. Yana da wani na roba igiyar, wadda ta ƙunshi connective nama Kwayoyin, wanda ya samar da tallafi a ko'ina cikin jiki. A notochord aka located tare da jiki da kuma ci gaba cikin rayuwa a cikin wasu jinsunan, kira ƙananan tsirkiya. Su ne wakilan da superclass jawless: lamprey da hagfish. A cartilaginous kifi, sharks da kuma haskoki, dukan kwarangwal aka hada da connective nama da kuma yana da guda tsarin a matsayin tsirkiya. Ta, bi da bi, da aka adana a cikin wadannan kwayoyin rayuwa.

Abin da sa a cikin zargin da ciki kwarangwal

Mene ne ma'anar tsirkiya? Biology gan ta bayyanar a Amphioxus, sa'an nan sauran dabbobi da muhimmanci aromorphosis. An kai ga ci gaban da goyon bayan tsarin da kuma motsi cewa ka fito a cikin ta farko ƙasar dabbobi. Wannan yarda su don samun matsakaicin amfani a ci ƙasar, kuma su yi tsayayya, musamman da korau tasiri sojojin na nauyi da kuma sauran m muhalli dalilai.

A m dabba kungiyar, da ya ce vertebrate guringuntsi maye gurbin axial tufka tsarin, wanda ya kunshi osseous abubuwa - vertebrae. Wadannan sun hada da wakilan mafi azuzuwan na ƙasar dabbobi, kamar halittar dabba mai kafafuwa, da abubuwa masu rarrafe, da tsuntsaye da kuma dabbobi masu shayarwa. Domin na cikin ruwa rayuwa, da ciwon kashin, sun hada da kungiyoyin fitar kasusuwan jikinsu kifi: carps, Clupeiformes, Perciformes, da dai sauransu ...

A ci gaba da duk na sama kungiyoyin dabbobi sun shagaltar da rinjaye matsayi a cikin fauna na duniya. Wannan ne da goyan bayan gudanar da bincike da cewa riko da kimiyya da kuma ilmin halitta. A tsirkiya - shi ne jiki, kyale dabbobi don gasa tare da kwaro a gwagwarmayar rayuwa.

Da farko chordates

Mutane da yawa Dabbobi, masana kimiyya so mu gane da dabba, wanda tsarin da za a iya gani a matsayin wata mahada tsakanin kwaro da vertabrate. A tsakiyar karni XIX Rasha embryologist Kovalevsky bayyana tayi ci gaba unremarkable mazauni na Black Sea - Amphioxus saba.

Translucent halitta sama zuwa 8 cm, da kuma kamar kifi ba tare da wani shugaban tsirkiya riƙe cikin ransa. Amphioxus tabbatar da tsaka-tsakin sifa, kasancewar wanda for haka dogon nemi ilmin halitta. Tsirkiya - wani tsarin, da bayyanar wanda ya tabbatar da yanayin juyin halitta hanya. Features tayi zai tsarin (gaban uku jam yadudduka) da kuma ontogenesis Amphioxus tabbatar da zato cewa magabatan chordates ne kwayoyin da ba su da ciki kwarangwal.

Bookmark da axial kwarangwal

Formation na tsirkiya daga daban-daban kwayoyin ne game da wannan, ko da yake lokacin da tazara a wanda wannan ya auku iya bambanta. Alal misali, mutum tayi connective igiyar bayyana a cikin wani a baya lokacin da tayi gaba, kuma ta shafin da sauri fiye da abin da na kifi ko wasu vertabrate. A baya aksali nuclei kafa a karkashin na tsarin jijiya tube. Na farko hanji rabo kira hordomezodermalnym appendage tasowa tsirkiya vertabrate.

Biology da Medicine, daki-daki izuchyut matakai abin da ke faruwa a cikin lokaci na gastrulation cewa ya bayyana take hakkin fetal ci gaba, wanda zai iya haifar wani karu a fahimcin muhimmancin, bayyanar munanan kuma mutuwa daga wani tayi. Rashin sunadaran alamar axial gabobin: da na tsarin jijiya tube, notochord, hanji - shi ne mai hatsari, don haka al'ada hanya na ciki a farko trimester da matukar muhimmanci ga kiwon lafiya na haifa ba.

A bambancin da muhimmancin da irin chordwise

A wakilan wannan babban rukuni na kwayoyin suna sosai saba da daban-daban muhalli abubuwan da shagaltar da dukkan halittu a qasa muhalli maharibai. A hydrosphere, gida zuwa fiye da dubu 20. Nau'in kifi cewa suna dauke da mafi tsoho chordates, da farfajiya da kuma zurfin da lithosphere suna cike da wani babbar dama siffofin halittar dabba mai kafafuwa, da abubuwa masu rarrafe da masu shayarwa, da kuma ƙasar da iska yanayi sanaki fiye da 8 da dubu. Birds. By irin tsirkiya shi ne kuma mutum alƙarya wadda rayuwar fundamentally canza fuskar duniya tamu.