Thayipha Chordates: izici isakhiwo zangaphakathi nezangaphandle

Uhlobo kuzithinta has ezingaphezu kuka-40 eziyinkulungwane. Ukuhlala zilwane. Lokhu kuhlanganisa bescherepnyh (tunicates futhi Amphioxus) kanye cranial (cyclostomes (lamprey), izinhlanzi, izilwane eziphila emanzini nasezweni, ezihuquzelayo, izinyoni nezilwane ezincelisayo). Abamele lolu hlobo zitholakala kuwo wonke umhlaba futhi kuzo zonke izindawo. Iningi chordates abakhuthele, yokuphila yeselula, kodwa kukhona izinhlobo anamekwe substrate - tunicates. Ubukhulu nesisindo Ziyashiyana uhlobo futhi lokhu kuncike uhlobo imvelo nezilwane eziphila kuyona.

Naphezu kweqiniso lokuthi izilwane ehlangana uhlobo kuzithinta, ezahlukene esibukekayo, izici yangaphakathi isakhiwo, indlela yokuphila kanye imvelo, bona babe ezinye izici ezivamile. Ukuze ubone ukuthi ukufana kusiza isici jikelele chordates.

Zonke chordates babe:

• Axial skeleton, okumelelwe kuzithinta at bescherepnyh nomgogodla e cranial. Uhlaka lwamathambo has ukuma Strand eyenza umsebenzi ukusekela futhi ukunika kuyaqina umzimba.

• Gill izimbotshana emphinjeni. Ngo protostomes eziphilayo ezihlala sonke isikhathi emanzini futhi ungashiyi ke, gill izimbotshana ahlale kukho konke ukuphila. Futhi deuterostome owashiya izindawo zasemanzini, bese enye ngemuva kwenye (amahlengethwa, imikhomo, izingwenya), nezilwane zasezweni Gill izimbotshana khona kuphela izigaba ezithile yentuthuko embryonic, bese iyanyamalala. Esikhundleni salokho, tisebenta emaphashini - ukuphefumula nemizimba yasemhlabeni.

• Sezinzwa uhlelo (CNS), okuyinto tube elise ohlangothini ngemuva. Ngo chordates bakudala kuyinto tube ozwakala uhlala kukho konke ukuphila, futhi izilwane ephakeme luhlukaniswe asebuchosheni nomgogodla. A kwalapho, okuyinto ukudlulisa kusukela ohlelweni sezinzwa, neuropathy sezinzwa ifomu uhlelo.

• Sokujikeleza irherho le-closed. Inhliziyo, efana neural tube luluhlangothi ventral zomzimba.

Chordates banezimfanelo ehlukile ohlotsheni oluthile lwento ephilayo, ngenxa indlela yabo yokuphila futhi kwendawo kanye uzivumelanise nalo. Ngaphezu izibonakaliso umehluko kusuka nezinye izinto eziphilayo e chordates futhi zifana nezinye izilwane. Lezi ezifana ngazo nalo:

• wesimethri Bilateral okungukuthi esingokwemvelo izimpethu flat, izinambuzane kanye nezinye izinto eziphilayo.

• Kukonke (kungenjalo yesibili umzimba ingaphakathi), lapho izitho zangaphakathi zitholakala. ingaphakathi yesibili livela annelids.

• Have umlomo yesibili kwakhiwa okuyinto ngesikhathi gastrula esiteji by odongeni ukuphumelela.

• Metameric ilungiselelo zemizimba (segmental), ngokucacile esigabeni embryonic ne-e chordates bakudala, ezilwaneni omdala kungabonakala isakhiwo kwemisipha futhi eksisi emgogodleni. Ngenxa lolu hlobo kuzithinta enezimpawu zifana annelids nezinambuzane.

• Ukuba khona isitho izinhlelo - kwegazi, zokuphefumula, abakaze, wokugaya ukudla, excretory, zokuzala.

Ngakho, uhlobo kuzithinta ihlanganisa izilwane, izimpawu wesimethri zamazwe amabili, futhi ngokuvamile, khona gill izimbotshana kusaqalwa yentuthuko kanye ukuvela lwamathambo yangaphakathi - Amanothi, phezu esemgwaqweni neural tube. Ngaphansi kuzithinta kuyinto tube wokugaya ukudla.