Yintoni na le gametophyte (iintlobo, iimpawu, iimpawu)

Yonke into ephilayo uhamba ngendlela ethile Umjikelo wobomi: ukusuka ekuqaleni (bookmarks) ekufeni (ukufa), kwaye isityalo ayikho umnyinyiva. osemqoka lwabo lokwahlula yinkqubo yokuzala ukuba alternating sporophyte kunye gametophyte.

Kwaye yiloo nto le gametophyte - ukuhlalutya ngokweenkcukacha kweli nqaku. Kufuneka kuthiwe rhoqo gametophyte ayenziwanga zodwa, kwaye apho, kunye sporophytes okanye kuxhomekeke ngqo kuwo.

Yintoni gametophyte?

Igama elithi "gametophyte" livela kwigama lesiGrike elithetha "gamete", okt. E. cell Reproductive kunye phyton (ezityalo) kwaye bubonakala isizukulwana ngokwesini okanye omnye amanqanaba yophuhliso zezityalo. Eziphilayo, isizukulwana yintsholongwane haploid unalo unyulo ileta - «n».

iintlobo

Ukuze uqonde ukuba gametophyte kudingeka ukuba uqonde oko ibunjiwe loo nto ngayo. Gametophyte yi isici esasenza eziphawula izityalo akwi ukuba udidi ibihlungu ngaphezulu. Kuxhomekeka umahluko kwi gametophyte ukuze aphuhlise gametangia (amalungu okuzala of ukuzala) kweentlobo ezimbini: inkunzi nemazi.

Iimpawu yokuza-

yonke inkqubo ye ukuzala kwizityalo na ngohlobo conjugation (iiseli okt. E. ezimbini ezizimeleyo protoplast fusion kwezityalo). Ngamaxesha amaninzi omnye umntu inye ngaxeshanye ukuphuhlisa zombini gametes okanye sikuyo. Kodwa ke kukho iimeko xa iingxoxo abaphuhlisa uhlobo nje omnye, kunye gametes kuphela phezu kwezinye. Ngabanye, leyo iphuhlisa imbewu, ebizwa ngokuba sporophyte, nalowo apho kwakhiwa gametes - gametophyte.

Gametophyte kwizityalo

Gametophyte ke bunjalo, kunye zobufanasini. Xa nuclei sporophyte diploid banalo isethi chromosome, kodwa babe bona haploid gametophyte. Uninzi olukhulu ulwelwe kakhulu kwaye phantse zonke izityalo eziphezulu babe indlela eyodwa kuphuhliso nokungazinzi koqoqosho kunye alternation kwizizukulwana, ezithi olunokuveliswa asexually nangezifo.

Ngokwalo, inkqubo lokuzalanisa angamelwa ngolu hlobo lulandelayo: gametophyte → → imveliso gamete ngxubevange gametes elilodwa ukubunjwa → → → uphuhliso sporophyte diploid njalo njalo.

isakhiwo Gametophyte kakhulu ezahlukeneyo, yaye oku kuxhomekeke kuhlobo utshintsho kwezizukulwana abo okanye ezinye iintlobo zezityalo. Umzekelo, lona lisiza elifana neli alternation mdla kwizizukulwana (isomorphic), ngoko gametophyte zazimele iyunithi ozimeleyo, nto leyo eyahlukileyo kwaye ayahlukanga ukusuka sporophyte efanayo.

Kwaye apha lona lisiza laminaria, leyo ube umjikelo hlukile zophuhliso (heteromorphic), lo gametophyte yahluke ngokupheleleyo, yahlukile ukusuka sporophyte, isakhiwo ngohlobo phantsi-aphuhliswe yaye branched thalli filamentous. Phantse bonke abameli sporophytes, kuquka kwi omfisi, lo gametophyte ntoni ngokwaneleyo kwaye kukho ixesha elifutshane kakhulu.

Ngenxa yokuba kule khosi zazivelela izityalo yeeklasi aphezulu kwabakho ukwehla kakuhle gametophyte, baye balahlekelwa bangoobani ngesondo. Umzekelo, izityalo imbewu ezilahlekileyo ngokupheleleyo isizukulwana kwabasetyhini, kwaye zonke izigaba zophuhliso ukuba kwenzeka sporophyte.

gametophyte Female gymnosperms imelwe endosperm haploid multicellular okanye archegonia ngaphezulu njengoko pine okanye ezinye gymnosperms ngokulandelelanayo. Xa abameli ravnosporovyh prothallia izityalo omfisi kukho amadoda namabhinqa.

izityalo imbewu gametophyte inkunzi uhlobo umungu kwaye luphumba microspores eyenza gametes e zokuntshulisa umungu ityhubhu. Kodwa prothallia ravnosporovyh omfisi - ulala.

Ngoko ke, lo gametophyte ayikho ixhomekeke ixesha kwezityalo okanye izityalo yobomi, kwaye kuphela uhlobo yayo kunye neempawu yendaleko.

isiphelo

Ngoko ke, lo gametophyte, ekubeni isizukulwana ngokwesini kuphuhliso yezityalo kunye eziphawula alternation ezithile kwaye silandelelaniswe kakuhle kwizizukulwana ngohlobo lwayo, inemisebenzi eziliqela. Okokuqala, ukuba lithatyathwe ingxabano iseti haploid zofuzo kunye gametes kusoloko iintlobo akukhathaliseki nokuba loo nto ezizodwa esini okanye iiseli eziqhelekileyo kwezityalo.

Ngoku uyazi ukuba yintoni gametophyte yaye ziziphi iimpawu zayo.