Qav muaj hom cleavage dab tsi?
Qav muaj hom cleavage dab tsi?

Video: Qav muaj hom cleavage dab tsi?

Video: Qav muaj hom cleavage dab tsi?
Video: Maiv pov tus niam hluag tuaj pab nws ntxhua pam lev. 2024, Kaum ib hlis
Anonim

Cleavage nyob rau hauv feem ntau Qav thiab salamander embryos yog radially symmetrical thiab holoblastic , ib yam li echinoderm cleavage. Lub qe amphibian, txawm li cas los xij, muaj ntau ntau yolk. Qhov no yolk, uas yog concentrated nyob rau hauv cov zaub hemisphere, yog ib tug impediment rau cleavage.

Cov lus nug tseem yog, dab tsi yog hom cleavage?

Plaub loj holoblastic hom cleavage tuaj yeem pom dav dav: radial, kauv, ob sab, thiab rotational. Cov qe qe uas muaj ntau dua ntawm yolk undergo meroblastic cleavage tom qab fertilization, nyob rau hauv uas tsuas yog ib feem ntawm lub zygote undergoes cleavage.

Ib sab saum toj no, Discoidal cleavage yog dab tsi? Kev txhais ntawm disoidal cleavage .: meroblastic kev tawg nyob rau hauv uas ib tug disk ntawm hlwb yog tsim nyob rau hauv tus tsiaj ncej ntawm lub zygote (raws li nyob rau hauv noog qe)

Kuj nug, hom cleavage twg yog qhia nyob rau hauv cov tsiaj?

Cov tsiaj txhu tso saib rotational cleavage , thiab ib qho isolecithal tis ntawm yolk (sparsely thiab evenly faib).

Dab tsi ntawm cleavage neeg muaj?

Cleavage tej zaum yuav tag nrho (holoblastic) los yog ib nrab ( meroblastic ). Nyob rau hauv cov qe uas tsis muaj yolk los yog tsuas yog ib tug nruab nrab ntawm yolk, cytokinesis kiag li faib lub cell thiab cleavage yog holoblastic. Ntawm no, cleavage furrows yog tsim tag nrho txoj kev los ntawm lub zygote ua . Daim ntawv no ntawm cleavage tshwm sim nyob rau hauv cov tsiaj xws li tib neeg.

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