Txhua yam kab mob uas muaj sia nyob mus txog ib lub voj voog ntawm lub neej: los ntawm kev xav (ntev) mus rau kev tuag (kev tuag), thiab cov nroj tsuag tsis muaj kev zam. Lawv qhov txawv feature yog cov txheej txheem luam tawm, uas muaj nyob rau hauv kev hloov ntawm sporophyte thiab gametophyte.
Tab sis dab tsi yog gametophyte - peb yuav tshuaj xyuas kom meej ntxiv hauv kab lus no. Nws yuav tsum tau hais tias feem ntau gametophyte tsis cais, tab sis muaj nyob ua ke nrog cov sporophyte lossis ncaj qha nyob ntawm nws.
gametophyte yog dab tsi?
Lo lus "gametophyte" los ntawm Greek lo lus "gamete", piv txwv li cov qe menyuam yaus thiab phyton (cog) thiab hauv kev txhais lus txhais tau tias kev sib deev tiam lossis ib theem ntawm kev loj hlob ntawm cov nroj tsuag. Nyob rau hauv biology, lub haploid kev sib deev tiam muaj ib tsab ntawv xaiv - "n".
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Yuav kom nkag siab tias gametophyte yog dab tsi, koj yuav tsum nkag siab tias nws tsim thiab nws yog dab tsi. Lub gametophyte yog ib qho tshwj xeeb uas qhia txog cov khoom ntawm cov nroj tsuag mus rau cov chav kawm ntawm cov spores siab dua. Nyob ntawm qhov sib txawv ntawm gametophyte, gametangia (generative organskev yug me nyuam) ntawm ob hom: poj niam thiab txiv neej.
Txoj kev tsim tawm
Tag nrho cov txheej txheem ntawm kev sib deev hauv cov nroj tsuag tshwm sim nyob rau hauv daim ntawv ntawm conjugation (piv txwv li, fusion ntawm protoplasts ntawm ob lub hlwb vegetative ywj siab). Feem ntau, ob qho tib si gametes thiab spores tuaj yeem tsim ib txhij ntawm tib tus neeg. Tab sis kuj tseem muaj cov xwm txheej zoo li no thaum spores tsim tsuas yog ntawm ib hom, thiab gametes tshwj xeeb rau lwm tus. Ib tus neeg uas tsim cov spores hu ua sporophyte, thiab ib qho ntawm gametes tsim yog hu ua gametophyte.
Gametophyte hauv cov nroj tsuag
Gametophyte yog bisexual thiab unisexual. Hauv sporophyte, cov nuclei muaj diploid chromosome teeb, tab sis hauv gametophyte lawv yog haploid. Feem coob ntawm cov algae uas muaj kev sib koom siab heev thiab yuav luag txhua cov nroj tsuag siab dua muaj cov qauv pom tseeb hauv kev loj hlob thiab kev hloov ntawm ntau tiam neeg uas yug me nyuam asexually thiab kev sib deev.
Schematically, cov txheej txheem luam tawm tuaj yeem sawv cev raws li hauv qab no: gametophyte → gamete ntau lawm → gamete fusion → zygote tsim → diploid sporophyte kev loj hlob → thiab lwm yam.
Cov qauv ntawm gametophyte yog ntau haiv neeg thiab nws ncaj qha nyob ntawm hom kev hloov pauv hauv qee hom nroj tsuag. Yog li, piv txwv li, nyob rau hauv algae, ib tug niaj hnub hloov ntawm tiam (isomorphic) yog pom, yog li ntawd lawv gametophyte yog sawv cev los ntawm ib tug ywj siab unit uas muaj nyob rau hauv nyias thiab tsis txawv ntawm tib sporophyte.
Tab siskelp algae, uas muaj qhov txawv (heteromorphic) kev loj hlob voj voog, gametophyte muaj cov qauv sib txawv kiag li, txawv ntawm cov sporophyte, nyob rau hauv daim ntawv ntawm underdeveloped filamentous thiab branched thalli. Hauv yuav luag txhua tus neeg sawv cev ntawm sporophytes, suav nrog ferns, gametophyte yog qhov tsis tsim nyog thiab muaj nyob rau lub sijhawm luv luv.
Vim qhov tseeb tias nyob rau hauv cov chav kawm ntawm evolution nyob rau hauv cov nroj tsuag ntawm cov chav kawm siab dua ib tug du du ntawm gametophyte tau pom, lawv poob lawv poj niam txiv neej. Piv txwv li, cov noob nroj tsuag tau ploj tag nrho cov poj niam tiam, thiab txhua theem ntawm lawv txoj kev loj hlob tshwm sim ntawm sporophyte.
Tus poj niam gametophyte ntawm gymnosperms yog sawv cev los ntawm ntau lub cellular haploid endospermia lossis ob peb archegoniums, xws li hauv ntoo thuv lossis lwm yam gymnosperms, raws li. Hauv cov neeg sawv cev ntawm isosporous ntawm cov nroj tsuag zoo li fern, cov kev loj hlob muaj ob leeg.
Tus txiv neej gametophyte ntawm cov noob nroj tsuag muaj cov paj ntoos thiab pib los ntawm microspore uas tsim gametes, loj hlob mus rau hauv lub paj paj ntoos. Tab sis kev loj hlob ntawm isosporous ferns yog bisexual.
Yog li, gametophyte tsis nyob ntawm lub sijhawm ntawm lub caij loj hlob lossis lub neej ntawm cov nroj tsuag, tab sis tsuas yog nyob ntawm nws hom thiab cov yam ntxwv hloov pauv.
Zoo kawg
Yog li, gametophyte, ua kev sib deev tiam hauv kev loj hlob ntawm cov nroj tsuag thiab cov yam ntxwv los ntawm ib qho kev hloov pauv ntawm ntau tiam neeg hauv nws hom, muaj ntau yam nta. Ua ntej ntawm tag nrho cov, nws yog tsim los ntawm spores, muaj ib tug haploid txheej ntawm chromosomes thiab ib txwm tsim.gametes, tsis hais seb lawv puas yog cov kab mob sib deev tshwj xeeb lossis cov hlwb zoo tib yam.
Tam sim no koj paub tias gametophyte yog dab tsi thiab nws yog dab tsi.
