Axial pob txha - chord. Biology ntawm nws functions thiab tseem ceeb

Lub zog ntawm lub cev kev pab txhawb nqa thiab tiv thaiv cov hauv nruab nrog cev ntawm cov tsiaj tej zaum yuav nqa tawm nyob rau hauv ob txoj kev. Nyob rau hauv thawj cov ntaub ntawv, ib tug txheej cev pob txha - plhaub. Nws yog tsim los ntawm cov chitin, rau ntau dua lub zog ntawm lub impregnated calcium ntsev, phosphorus los yog pob zeb ntais. Crustaceans, kab laug sab, mites, kab - yog cov tsiaj uas muaj plhaub thiab hu ua invertebrates. Lwm pab pawg neeg ntawm fauna thaum lub sij hawm embryogenesis ntaub ntawv ib tug nrog cev pob txha, uas ua lub luag hauj lwm chord.

Biology piav nws cov tsos raws li ib tug tshwm sim ntawm tus txheej txheem ntawm organogenesis - lub tsim ntawm ib tug complex ntawm axial kabmob. Qhov no muaj xws li cov neural raj, lub plab thiab lub chord. Tshwm sim ntawm elastic connective qaum rau neurula theem embryo yog ib txwm tibneeg thiab tsiaj txhu mus rau lub hom tsiv. Cia peb kawm tus txheej txheem no nyob rau hauv ntau yam, raws li tau zoo raws li hais lub luag hauj lwm ntawm lub axial pob txha nyob rau hauv vertebrates.

Yuav ua li cas yog ib tug chord hauv ib?

Kev Txiav Txim ntawm no ib feem ntawm lub embryo yog raws li nram no: nws yog unsegmented notochord muaj elastic connective cov ntaub so ntswg. Nws yog ib qho tseem ceeb nyob rau hauv lub embryogenesis ntawm cov tsiaj xws li chordal. Bookmark chord tshwm sim nyob rau hauv lub neural raj ntawm kab chordomesoderm uas yog derived ectoderm thawj hnyuv. Thaum lub sij hawm organogenesis, nws hloov lub plab hnyuv raj, nyob rau hauv qab chord. Cov dab piav saum toj no yog complex thiab kawm nyob rau hauv lub chav kawm ntawm lub general high school biology. Yuav ua li cas los mus piav qhia rau yau cov tub ntxhais kawm, cov tub ntxhais kawm ntawm kev kawm txog tsiaj txhu hais tias qhov no chord? Biology (Qib 7) qauv tsim xaiv cov piv txwv ntawm cov leeg nrob axis Amphioxus. Cia peb kawm no qhov teeb meem nyob rau hauv ntau dua kom meej.

Cov yam ntxwv ntawm cov subtype bescherepnyh

Qhov no systematic pab pawg neeg muaj ib tug hauv chav kawm ntawv - Amphioxus. Tsiaj txhu nyob rau hauv qab ntawm cov dub hiav txwv, siv feem ntau ntawm nws lub neej faus nyob rau hauv cov xuab zeb thiab raug nyob rau hauv qhov chaw ntawm lub hauv pem hauv ntej thaum xaus ntawm lub cev, surrounded los ntawm tentacles. Los ntawm lub translucent lub cev yog illuminated los ntawm ib tug tuab raj - chord. Biology txiav txim siab nws raws li ib feem ntawm lub licas ntawm cov tsiaj. Notochord nyob rau hauv Amphioxus, zoo li lwm yam txheej thaum ub chordates - lampreys thiab hagfish, hais txog lub jawless vertebrates, tam sim no thoob plaws ontogeny Nws plays lub luag hauj lwm ntawm lub axial pob txha. Nyob rau hauv tas li ntawd mus cov kab mob teej tug mus rau bescherepnyh thiab cyclostomes, notochord tsawv nyob rau hauv ib co ntses. Xav txog cov yam ntxwv ntawm lawv cov qauv.

cartilaginous fishes

Common stingray, hiav txwv hma liab, sawfish, spiny dogfish - ib tug title ntawm sib sib zog nqus hiav txwv inhabitants: stingrays thiab sharks. Raws li ib feem ntawm cov nyiaj them yug system thiab lub zog muaj xws li ib tug cartilaginous cev pob txha thiab cov nqaij. Ntawm vertebral lub cev nyob rau hauv cov leeg nrob kwj dej yog residual tawg tsam ntawm embryonic hlwb txha nqaj qaum. Qhov no feature yog ib txwm hauv cov qauv ntawm cartilaginous fishes, uas txawm nyob rau hauv adulthood cov fwm chord. Biology piav raws li nram no: thaum lub sij hawm embryogenesis notochord generates equidistant apart constrictions, nyob rau hauv uas tus txheej txheem yog pib los ntawm calcareous deposits lug. Lawv maj mam faib cov chord rau hauv lub cev ntawm lub pob txha caj qaum pob txha mos, connective cov ntaub so ntswg thiab nws qhov chaw nyob twj ywm hauv lub intervertebral discs.

Nta ntawm cov qauv ntawm cov ntses Sturgeon Series

Ua ke nrog cov sharks thiab rays, uas lawv muaj npaum li cas nyob rau hauv ntau, cov neeg sawv cev ntawm no pab pawg neeg mus rau lub ancient ntses. Rau sturgeon, Beluga, stellate qauv yog yus muaj los ntawm tej nta li puab cartilaginous cev pob txha thiab notochord. Biology hais tias tus pog koob yawg koob ntawm sturgeon nyob rau hauv lub Devonian lub sij hawm ntawm lub Paleozoic era. Los ntawm no taw tes rau lawv lub cev tsis tau hloov ntau npaum li cas. Adult ntaub ntawv muaj txha caj qaum them nrog ib tug plhaub ntawm tuab connective cov ntaub so ntswg thiab ntxiv lub neej. Tshwj xeeb qhuav chord stellate sturgeon, sturgeon thiab lwm yam sturgeon nyob rau hauv Russia tau ntev tau siv nyob rau hauv khoom noj khoom haus raws li ib tug filling rau pies thiab ncuav qab zib, hu rau nws vyazigoy.