Mene ne gametophyte (iri, halaye, da halaye)

Kowane mai rai kwayoyin ke ta wani rai sake zagayowar: daga ganewa (alamomin) zuwa mutuwa (mutuwa), da kuma shuka ba wani togiya. Su bayãnin hukuncin alama ne haifuwa aiwatar da cewa an alternating sporophyte da gametophyte.

Kuma abinda ke cikin gametophyte - bincika a more daki-daki a cikin wannan labarin. Ya kamata a ce cewa sau da yawa sosai da gametophyte ba ware, kuma akwai, tare da sporophytes ko kai tsaye dogara a kan shi.

Mene ne gametophyte?

Kalmar "gametophyte" da aka samu daga kalmar Helenanci for "gamete", watau. E. Haihuwa cell da phyton (shuka) da kuma fassara a matsayin jima'i tsara ko daya daga cikin matakai na shuka ci gaba. A ilmin halitta, da haploid jam tsara yana da wata wasika nadi - «n».

iri

Don gane cewa gametophyte wajibi ne a fahimci yadda shi ne kafa da kuma cewa shi ne. Gametophyte ne a rarrabe characterizing da tsire-tsire na ga aji na mafi girma spore. Dangane da bambantawa a gametophyte iya ci gaba gametangia (generative gabobin da jima'i haifuwa) na iri biyu: namiji da mace.

kiwo Features

A dukan tsari na jima'i haifuwa a tsire-tsire ne a cikin nau'i na Tasrifu (watau. E. biyu m protoplast Fusion vegetative Kwayoyin). Sau da yawa wanda kuma wannan mutum zai iya lokaci guda samar da duka biyu gametes ko spores. Amma akwai lokuta lokacin da muhawara ne masu tasowa kawai daya type, kuma gametes kawai a kan sauran. Mutane daya-daya, wanda tasowa spores, da ake kira sporophyte, da kuma daya a kan wadda gametes aka kafa - gametophyte.

Gametophyte a tsire-tsire

Gametophyte ne bisexual da kishili. A sporophyte diploid nuclei suna da wani chromosome sa, amma da suka haploid gametophyte. Mafi yawan wa sosai algae kuma kusan duk mafi girma shuke-shuke da jinsin juna a cikin cyclical ci gaba da kuma canzawar ƙarnõni, wanda aka sake bugawa asexually da kuma jima'i.

Schematically, kiwo tsari za a iya wakilta kamar haka: gametophyte → → samar da gamete Fusion na gametes zygote samuwar → → → ci gaban mai diploid sporophyte da sauransu.

Gametophyte tsari ne quite bambancin, da kuma wannan ya dogara da irin ta yin canji wadanda ko sauran nau'o'in shuke-shuke. Alal misali, algae an kiyaye monotonous canzawar al'ummomi (isomorphic), don haka gametophyte suka wakilta wani m naúrar, wanda shi ne raba da ba ya bambanta daga wannan sporophyte.

Kuma a nan a laminaria algae, wanda da rarrabe (heteromorphic) ci gaban sake zagayowar, da gametophyte ne gaba daya daban-daban, daban-daban daga sporophyte, a tsarin a cikin nau'i na karkashin-raya da kuma branched filamentous thalli. Kusan dukkan wakilan sporophytes, ciki har da a fern, da gametophyte bai tasowa da kuma a can ne mai matukar gajeren lokaci.

Saboda gaskiya cewa a cikin shakka daga juyin halitta a cikin shuke-shuke daga cikin manya azuzuwan akwai mai santsi rage daga cikin gametophyte, sun yi hasãrar jima'i ainihi. Alal misali, iri shuke-shuke gaba daya rasa ƙarni na mata, da kuma duk matakai na raya kasa da suka faru a kan sporophyte.

Mace gametophyte gymnosperms wakilta kwayar haploid endosperm ko fiye archegonia kamar yadda Pine ko wasu gymnosperms bi da bi. A ravnosporovyh wakilan prothallia fern tsire-tsire ne na biyu mata da maza.

Male gametophyte iri shuke-shuke yana da nau'i na pollen kuma fãra daga microspores wanda Forms gametes a germinating pollen tube. Amma prothallia ravnosporovyh fern - bisexual.

Saboda haka, gametophyte ba a dogara a kan lokaci ciyayi ko shuka rayuwa, da kuma kawai ta irin da juyin fasali.

ƙarshe

Saboda haka, gametophyte, kasancewa jima'i tsara a shuka ci gaba da kuma characterizing takamaiman kuma bi da bi canzawar ƙarnõni a cikin irin, yana da fasali. Da farko, shi ne kafa daga wata muhawara yana da wani haploid sa na chromosomes da gametes ko da yaushe siffofin ko da kuwa ko shi ne mai na musamman jima'i gabobin ko al'ada vegetative Kwayoyin.

Yanzu ka san abin da a gametophyte da kuma abin da suke da fasali.