Kodi gametophyte (mitundu, maonekedwe, makhalidwe)

Chamoyo chilichonse moyo udzadutsa wina mayendedwe amoyo: kwa lingaliro (bookmarks) imfa (imfa), ndipo mbewu si zosiyana. Mbali awo zimasiyanitsa ndi njira kubalana kuti alternating sporophyte ndi gametophyte.

Ndipo ndicho chimene gametophyte - yosanthula mwatsatanetsatane m'nkhani ino. Iwo ayenera kuti nthawi ya gametophyte si n'kopanda anthu, ndipo kumeneko, pamodzi ndi sporophytes kapena mwachindunji ukudalira pa izo.

Kodi gametophyte?

Mawu akuti "gametophyte" anachokera ku mawu achigiriki otanthauza "gamete", mwachitsanzo. E. ubeleki selo ndi phyton (mbewu) ndi anamasuliridwa ngati m'badwo kugonana kapena mmodzi wa magawo chitukuko zomera. Mu zamoyo, ndi haploid nyongolosi m'badwo ali ndi kalata lakuti - «N».

mitundu

Kuti timvetse kuti gametophyte m'pofunika kudziŵa mmene likakhazikitsidwa komanso kuti ali. Gametophyte ndi ofala amakhala zomera a kalasi ya spore apamwamba. Malinga zosiyanasiyana mu gametophyte ya khateyo gametangia (ziwalo zobereka ya kubereka) mitundu iwiri: Mwamuna ndi mkazi.

kuswana Features

Dongosolo lonse la kubereka mu zomera mu mawonekedwe a conjugation (ie. E. awiri palokha protoplast maphatikizidwe vegetative maselo). Nthawi zambiri munthu ndi mmodzi akhoza imodzi kukhala gametes onse kapena spores. Koma pali milandu pamene kutsutsana ndi osauka mtundu umodzi basi, ndipo gametes chokhazikika pa ena. Munthu, amene akufotokozera spores, wotchedwa sporophyte, ndipo amene gametes anapanga - gametophyte.

Gametophyte zomera

Gametophyte ndi bisexual ndi amuna kapena akazi okhaokha. Mu mtima sporophyte diploid ali khromozomu anapereka, koma iwo haploid gametophyte. Yosatheka ambiri kwambiri algae ndipo pafupifupi onse zomera apamwamba ndi chitsanzo osiyana mu chitukuko cyclical ndi kusinthana kwa mibadwo, amene chinaonekeranso asexually ndi kugonana.

Schematically, ndondomeko kuswana akhoza ankaimira motere: gametophyte → → yopanga gamete maphatikizidwe wa gametes zygote mapangidwe → → → pakhale sporophyte diploid ndi zina zotero.

Gametophyte kapangidwe ndi osiyanasiyana ndithu, ndipo izi zimatengera mtundu wa kusintha M'BADWO anthu kapena mitundu ina ya zomera. Mwachitsanzo, algae zimawonedwa wonyong'onya kusinthana kwa mibadwo (isomorphic), kotero gametophyte iwo ankaimira ankapoperamo ufulu umene uli wosiyana ndi sasiyana ku sporophyte chomwecho.

Ndipo pano pa laminaria algae, omwe chosiyana (heteromorphic) chitukuko adzizungulira, ndi gametophyte ndi chosiyana, wosiyana sporophyte, ndi kapangidwe mu mawonekedwe a pansi anayamba ndi nthambi filamentous thalli. Pafupifupi onse oimira sporophytes, kuphatikizapo pa fern ndi, gametophyte saganiza underdeveloped ndipo pali nthawi yochepa.

Chifukwa chakuti m'kupita kwa kusanduka zomera magulu chapamwamba panali kuchepetsa yosalala gametophyte, iwo analili kugonana. Mwachitsanzo, zomera mbewu anataya kwathunthu m'badwo wa akazi, ndi magawo onse a chitukuko zidzachitika pa sporophyte lapansi.

Female gametophyte gymnosperms ankaimira multicellular haploid endosperm kapena archegonia zambiri monga paini kapena gymnosperms ena motero. Mu oimira ravnosporovyh prothallia zomera fern ndi a amuna ndi akazi.

Male zomera gametophyte mbewu ali mawonekedwe mungu ndi limachokera ku microspores imene imagwiritsidwa gametes mu germinating mungu chubu. Koma prothallia ravnosporovyh fern - bisexual.

Choncho, gametophyte sadalira pa nthawi ya zomera kapena zomera, ndi chokhacho cha mtundu wake ndi mbali chisinthiko.

Pomaliza

Choncho, gametophyte, kukhala m'badwo chigololo chitukuko zomera ndi amakhala yeniyeni ndi yotsatana kusinthana kwa mibadwo mu mtundu wake, ndi zinthu zingapo. Choyamba, iwo anapanga kuchokera mkangano ali haploid ya DNA ndi gametes zonse mitundu kaya ndi apadera kugonana ziwalo kapena maselo vegetative.

Tsopano inu mukudziwa chimene gametophyte nanga paradaiso.