Axial masapo - samjun. Baeloji tsa mesebetsi ea eona le bohlokoa

Mesebetsi ya tšehetso 'mele le ho sireletsa litho tse ka hare ea liphoofolo e ka ho phethahatsoa ka litsela tse peli. Tabeng ea pele, e ntle masapo - shell. E entsoe ka chitin, bakeng sa matla a e khōloanyane ea ho tse tsetsoeng moriana k'halsiamo matsoai, phosphorus kapa ka silicon. Crustaceans, likho, mites, likokoanyana - ke liphoofolo tse nang le khetla 'me a bitsa invertebrates. sehlopha se seng sa liphoofolo nakong embryogenesis bopa e masapo hare, e leng etsa karolo samjun.

Baeloji e hlalosa ponahalo ea lona ka lebaka la ho tshebetso ya ho organogenesis - sebopeho sa e rarahaneng ea litho axial. Sena se akarelletsa ho tube neural, le e ntse likahare ka le samjun. Ketsahalo ea rekere connective khoele ho neurula sethaleng embryo eona ke pontšo ea batho le liphoofolo tse ho matleng a Mofuta o susumelletsang ho. A re hlahlobeng sena ka ho qaqileng ho feta, hammoho le ho hlakisa mosebetsi oa masapo axial ka vertebrates.

ke samjun ka baeloji eng?

Boikemisetso ba karolo ena ea embryo le e tjena: ho unsegmented notochord entsoeng ka rekere connective dinama tse nyenyane tse. Ke ea bohlokoa motsoako ka embryogenesis ea liphoofolo tse kang chordal. Bookmark samjun ho etsahala tlas'a tube neural ea kokoana-hloko chordomesoderm eo e nkiloeng ectoderm intestine mathomo. Nakong organogenesis, o ile a fetola tube mala, teng ka tlase samjun. Le thulaganyo boletsoeng ka holimo li rarahaneng, 'me ba ithuta ka tsela ea kakaretso ea baeloji sekolong se phahameng. Mokhoa oa ho hlalosa ho baithuti le monyenyane, liithuti tsa bophelo ba liphoofolo hore samjun ee? Baeloji (Kereiti ya 7) sebopeho thehoa ho hlahloba mohlala oa lesapo la mokokotlo a selekane Amphioxus. A re hlahlobeng taba ena ka ho qaqileng le ho feta.

Litšobotsi tsa subtype le bescherepnyh

sehlopha sena e hlophisitsoeng e na le sehlopha sa 'ngoe - Amphioxus. Liphoofolo phela ka tlase ho Leoatle le Letšo, ho qeta boholo ba bophelo ba hae a patoa lehlabatheng le pepesa holim'a qetellong ka pele ea 'mele, e lika-likelitsoe ke tentacles. Ka 'mele oa translucent e khantsitsoe ke tube, le letšo-letšo - samjun. Baeloji nahana e le karolo ea bohlokoa ea tsamaiso ea musculoskeletal la phoofolo. Notochord ka Amphioxus, joaloka chordates tse ling khale - lampreys le hagfish, e amanang le vertebrates jawless, joale ho pholletsa ontogeny O phetha karolo ea masapo axial. Ho phaella ho lintho tse bao e leng bescherepnyh le cyclostomes, notochord phehellang ho ba bang ba litlhapi. Nahana ka lintlha tsa sebopeho bona.

litlhapi cartilaginous

E Tloaelehileng stingray, leoatle phokojoe, sawfish, spiny dogfish - e le sehlooho ea baahi tebileng-leoatle: stingrays le lishaka. E le karolo ea tsamaiso ea bona tšehetso le mokhatlo oo e kenyeletsa masapo cartilaginous le mesifa. Pakeng tsa 'mele vertebral ka kanale lesapo la mokokotlo li likhechana barrel tsa embryonic lesapong la mokokotlo. Tsobotsi ena ke pontšo ea mohaho ka hare la litlhapi cartilaginous, ea ileng a esita le ka ho ba motho e moholo mokhoa o sa fellang bolokoa samjun. Baeloji o ile a hlalosa tjena: nakong embryogenesis notochord chelete equidistant constrictions ntle, eo ho eona tshebetso e qadile ke calcareous mobung dibopeho. Butle-butle ba arola samjun ka 'mele oa vertebrae lefufuru, connective dinama tse nyenyane tse' me likarolo tsa lona ba lule ka hare ho discs intervertebral.

Features ya sebōpeho sa tlhapi Sturgeon Series

Hammoho le lishaka le mahlaseli, eo ba na le lintho tse ngata tse tšoanang, baemeli ba sehlopha sena ho matleng a tlhapi ea boholo-holo. Bakeng sa Sturgeon, beluga, sebopeho stellate e tšoauoa ka makgetha a ho kang hare cartilaginous masapo le notochord. Baeloji e bolela hore baholo-holo ba Sturgeon hlaha ka nako Devonian tsa Paleozoic mehla. From ntlha ena ka kaheho ea bona e se e sa fetoha hakaalo. liforomo batho ba baholo ba le khoele lesapo la mokokotlo koahetsoeng ka khetla ea le letso-letso connective dinama tse nyenyane tse le ho tsoela pele bophelong. Ho khethehileng omisitsoeng samjun stellate Sturgeon, Sturgeon le Sturgeon tse ling Russia e telele 'nile ea sebelisoa ka lijo ka tlatselletsa bakeng diphae le phae, a bitsa e vyazigoy.