Kumiswa, Isayensi
Ifa Sex-ezixhunyiwe (incazelo)
Iningi eziphilayo (ngaphandle ezingavamile), ikusasa kungokwalabo lokhu noma lokhuya ubulili begazi kunqunywa ngesikhathi sokukhulelwa kwenzeka, futhi kuncike onjani-chromosomes ubulili iwela zygote. Kulokhu, kukhona ezinye izici kungafani nakwabesilisa noma neyensikazi uhlobo oluthile. izimpawu ezinjalo sengathi kuhlangene komunye abesilisa nabesifazane, "exhumene" phansi. Uyini ifa ubulili-exhumene futhi kungani izifo ezithile ezithinta amadoda kuphela noma abesifazane kuphela? Sizozama ukuphendula lo mbuzo nzima.
Umfana noma intombazane?
Ngaphambi kokuthi uqale ukuba uphendule umbuzo othi, yini ifa ubulili-exhumene, kubalulekile ukuba baqonde indlela ngendlela efanayo kukhona kumiswa umzimba ukuthi ungowesifazane noma owesilisa. Njengoba abafundi lesi sihloko basonta Sapiens zinhlobo Homo, ngokuqinisekile kuyoba mnandi kakhulu ukuze ufunde kabanzi mayelana nendlela le nqubo wenziwa abantu. Idinga ukuqonda ukuthi yini le nofuzo kwabangaphezu ubulili: ifa zezici, ubulili-exhumene, wabe ku izindlela likubeka ngokucacile, kanye nesidingo ukuqonda imithetho eyisisekelo ukwakheka eziphilayo of abesilisa nabesifazane ezahlukene.
Ngakho, kuzo zonke ingqamuzana yomuntu inama-chromosome angu-46. Kulawa, abameleli ezihlukahlukene zezinto eziphilayo ubulili 22 ngazimbili ezifanayo. Lezi-chromosomes abizwa ngokuthi "autosomes." eyodwa pair kuphela - ucansi Ama-chromosomes e - ngabameli a sex eqinile futhi engenzeleli babe umehluko othize. Ngo abesifazane, ama-chromosome ubulili ayafana: banayo ababili X (X) - chromosome. In amadoda, chromosome ubulili akheke ezahlukene, enye yazo-X-exhumene, kanti eyesibili - V (y) - chromosome. Phela, i-Y-chromosome ithwala inombolo encane lokhu ngezakhi ezingamaqoqo. Sex-exhumene ifa iphethini incike zofuzo efakwe ku-chromosome ocansini.
Ngokufanayo, ifa nobulili awukhona zonke izinhlobo. Ezinye izinyoni ingasheshi iduna ufuzo Y yayo Ama-chromosomes e: la uhamba KOMAMA X chromosome kuphela. Kukhona futhi izinhlobo zawo lapho ukuthuthukiswa umzimba female kudinga Y-chromosome, iduna, kunalokho, kukhona abathwali X chromosome amabii.
Homogametic futhi heterogamety
Ngu lokho yezizathu eyodwa zygote "uthole" X chromosome amabii, kuyilapho abanye Y-chromosome? Lokhu kungenxa yokuthi phakathi nokuvuthwa of gametes, okusho meiosis, wonke amaqanda ukufika 22 "evamile" ubulili chromosome nokukodwa X chromosome. Okungukuthi, emzimbeni owesifazane kukhona gametes ezifanayo. Isidoda amaseli ziyafana, kunezinhlobo ezimbili: ncamashi kwesigamu kubo ithwala ngokobulili X chromosome, kuyilapho abanye "uthole" Y-chromosome.
Floor, ukwakha gamete efanayo-chromosomes ubulili, ubizwa ngokuthi "homogametic". Uma gamete ezahlukene - ke heterogametic. Abantu heterogamety amadoda, abesifazane futhi homogametic.
Yikuphi isidoda ngeke zalisa iqanda incike ithuba. Ngakho, nge Amathuba 50/50 zygote uthola ezimbili X-chromosomes e noma X Y chromosome. Ngokwemvelo, esimweni sokuqala, intombazane ozokhula lesibili - umfana. Yiqiniso, kungase kube okuthile okuhlukile ezimweni ezithile, Amantombazane e ufuzo ka-U-chromosome noma abathwali isethi akuphelele zezakhi zofuzo, okungukuthi, kangakanani ezitokisini zabo kukhona kuphela ubulili chromosome eyodwa. Nokho, lokhu - kungase kwenzeke into eyivelakancane kakhulu.
Kungani uphawu kungenziwa "exhumene" nge phansi?
Manje ukuthi umfundi uyazi ukuthi zofuzo ubulili, ifa, esixhunyiwe ne phansi, uzobe kangcono indlela waqonda. Ngokuvamile ama-chromosome kukhona abezindaba esiyingqayizivele: umqondo umzimba womuntu ngamunye uba umnikazi "umtapo" imiqulu 46, okuyinto okhandlayo ukuchaza zonke izici nezici lomzimba wakhe. Inani ulwazi oluqukethwe zonke ingqamuzana yomuntu, angu-1.5 gigabytes! Ngaphezu kwalokho, chromosome ngayinye iqukethe ethize engxenyeni: umbala wamehlo nezinwele, umunwe dexterity, ivolumu inkumbulo yesikhashana, ukuthambekela akhuluphele ... Ngokuvamile ama-chromosome kukhona ezikhethekile kakhulu: ezinye banesibopho umzimba, kuyilapho abanye - I-umbala wamehlo, noma izinga izinqubo emsipheni .. . Nokho, ngenxa izakhi zofuzo ezinkulu ilwazi kulotshwe ku amaprotheni molecule - enzyme, enquma izici ukusebenza umzimba womuntu.
Ingxenye ukwaziswa kwezakhi zofuzo ikhodi eyisivikelo futhi Ama-chromosomes e ocansini. Ngakho-ke, izimpawu ukuthi 'zilotshwe' kuyi lezi Ama-chromosomes e, bungadluliswa kuphela kulabo abamele of a sex yemvelo: lena isakhi ifa ubulili-ezixhunyiwe. Ngakho, singathola isiphetho esibalulekile. Uma isakhi esithile sisebenza esisogwini omunye chromosome ubulili, le izazi zezinto eziphilayo ukhulume lo mkhuba ifa zezici, ubulili-ezixhunyiwe. Kulokhu, ifa salezi zici enezinto eziningi izici: zingabantu ngezindlela eziningi ngeke ukuzibonakalisa e ezahlukene abesilisa nabesifazane eziphilayo.
Izifundo zokuqala
Ufuzo kuqashelwe ukuthi ifa umbala iso e Drosophila facets kuyinto encike ngqo kwi ubulili ngabantu abanikazi alleles ezahlukene. Isakhi ukuthi inquma ukuthuthukiswa walokho okubomvu-Ilihlo evelele phezu zofuzo, "white uneso". Uma amehlo ebomvu yeduna, kuyilapho izinsikazi - mhlophe, khona inzalo isizukulwane sokuqala etholwe nenani elilinganako nabesifazane futhi abesilisa obomvu ngamehlo amhlophe. Uma sithola inzalo besilisa ngamehlo amhlophe kwaba owesilisa nowesifazane obomvu uneso, uthola nenani elilinganako iduna nensikazi obomvu okotshani. Ngakho, phenotype leduna trait esikhubazayo kuzibonakalisa kanengi ukudlula nabesifazane. Lokhu kwenza ukuba abantu esiphethweni sokuthi umbala isakhi sofuzo iso itholakala-X chromosome, okusho ukuthi ilifa wamehlo ku Drosophila - yilifa izici, kuhambisana phansi.
Ngokucacile exhumene ifa phansi
ifa Sex-exhumene onezici ezithile. Ukuthi yizinto ezihlobene yokuthi Y-chromosome ithwala abambalwa zezakhi zofuzo ngaphandle X chromosome. Ngakho-ke, izakhi zofuzo eziningi, okuyinto zitholakala-X chromosome, okuyinto eyenzeka emzimbeni wesilisa, akukho alleles ku-Y-chromosome. Ngakho-ke, iyiphi sakhi sofuzo esikhubazayo ejika-X chromosome akukwazi isakhi sofuzo allelic ku-Y-chromosome, okusho ukuthi ngempela izovela phenotype.
Kumele kuchaze ngenhla. Allele kuwuhlobo isakhi esisodwa. Allele kungaba izinhlobo ezimbili eziyisisekelo: i-ephezulu kanye esikhubazayo. Kulokhu, lo allele ovelele kule genotype ngempela kubonakala phenotypically futhi esikhubazayo - kuphela uma linikezwa isimo homozygous. Ukuze sicacise leli phuzu, ungakwazi kubangele ilifa wamehlo kubantu. Umbala incike lemali melanin ku sombala iris. Uma amehlo kancane melanin uzokhanya, uma eziningi - amnyama. Kulokhu, ngoba ebumnyameni iso umbala allele evelele unesibopho uma anakho ufuzo, umntwana kuyoba brown okotshani. Akunandaba ukuthi kokubili izakhi zofuzo ungomunye evelele enginayo noma esikhubazayo, okungukuthi, noma ngabe ingane ngesizathu homo- noma heterozygous. Kodwa blue eyes - kuqhathaniswa "abasha" kuguquka, okuyinto kulawulwa allele esikhubazayo. Bonke abantu blue uneso kukhona abathwali alleles ezimbili esikhubazayo, okusho ukuthi kukhona homozygous ngoba ngesisekelo wamehlo. isakhi sofuzo evelele, njengoba kusobala igama layo, obusa esikhubazayo uma omunye umntwana e ufuzo ka isakhi olulawula umbala iris, evelele, allele esikhubazayo ayikwazi bazikhulumele phenotypically.
Nokho, ubulili-chromosomes e Kulokhu zihlukile. Zabesilisa Y-chromosome lihlukile X chromosome ngobukhulu nangamandla umumo: kubukeka ngempela akulona cross, njengoba kunjalo nangazo zonke le-chromosome, kanye Y. incwadi Ngakho-ke, ezinye izakhi zofuzo, okuyinto zitholakala uzoboniswa ngisho uma kuyoba esikhubazayo eyodwa kuphela ukopishe: lokhu nokuxhumanisa ubulili ihlukile kwezinye izinhlobo ifa.
X-exhumene isifo esikhubazayo
Ubulili nokuxhumanisa, kubaluleke kakhulu ngoba zofuzo yezokwelapha, ngoba okwamanje kukhona kunamasonto angaba amakhulu amathathu izakhi zofuzo esikhubazayo ukuthi yenziwe yaba yasendaweni-X chromosome futhi abangele izifo zofuzo. Izifo ezihlala zihlanganisa hemophilia, myopathy, sokuwohloka kwemisipha, ichthyosis, ethambile X chromosome syndrome, iphimbo, kanye nezinye izifo eziningi.
Sex-exhumene ifa abantu wenziwa kanje. Uma isakhi esithile sisebenza normal itholakala kwelinye X chromosome yazalwa ngowesifazana, namadodakazi akhe uthole ngamzali kwamadodana. Kulokhu, intombazane, ogama ufuzo kwaba chromosome onesici, babe abathwala lesi sifo: ku phenotype ka isakhi sofuzo asabekayo alithintwa njengoba indodakazi ithola X chromosome evamile kuyise. Kodwa umfana uhlushwa isifo, okuyinto ukuba '' ngokumnikeza ifa kunina ngenxa allele evelele isakhi sofuzo ku-Y-chromosome akusho. Lokhu isici esibalulekile okufanele sicatshangelwe lapho enza isinqumo ngokuphathelene imisebenzi ifa ubulili-ezixhunyiwe.
Ifa X-exhumene isifo esikhubazayo wumumo kunalokho xaka. Ngokwesibonelo, isifo esifanayo, ngokuvamile phakathi kwezihlobo esiguli, itholakala umalume komama nomzala bakhe, azalelwe kusukela nodade kamama.
Dominatnye X-exhumene izifo
Lezi zifo kungavuka zabo bobubili ubulili. Omunye kungaba usho nezibonelo zawo ifa elinjalo, ubulili-exhumene njengoba yamathambo hypophosphatemic futhi amnyama izinyo koqweqwe lwawo.
Abaphethwe X-exhumene disorder evelele abesifazane njalo kabili kunabantu. owesifazane egula Amathuba 50% azo zonke ezithwala izifo izingane zabo, kanye Ogulayo - amadodakazi wodwa.
Ngezinye izikhathi, ifa ubulili-exhumene It kungabonakala nasemkhakheni izifo ayeyivelakancane ukuthi zinobuthi ukuze fetus owesilisa ngakho abesifazane kwandisa amathuba isisu nokuguqulwa.
Kungabangela ngokungenamkhawulo izibonelo ifa, ubulili-ezixhunyiwe. Ake isifo esinjengo sombala urinary melanoblastoz Bloch-Sultsberga. sombala urinary atholakala kuphela abesifazane: isakhi sibulala umbungu besilisa. Umzimba amantombazane abaphethwe yilesi sifo, kukhona ukuqubuka ngesimo Bubbles. Ngemva ukuqubuka hamba, ibala lesikhumba ayisibonelo ngesimo spray eddies. 80% eziguli, kunezinye ukwephulwa: kombungu kobuchopho futhi izibilini, amehlo kanye nohlaka lwamathambo.
hemophilia
Kunezindlela eziningana izifo ngofuzo, zitholakala kuphela ubulili eyodwa. Njengoba isibonelo salokho a nokuxhumanisa ubulili, hemophilia cishe zonke ebhukwinitifundvo. Hemophilia iyisifo lapho igazi akusho coagulate. imisebenzi eminingi labatinikele hemophilia ubulili ifa ukuxhunywa: Ungasho ukuthi lena cishe uyisibonelo yephuzu. Naphezu kweqiniso lokuthi hemophilia iyindlala, khona layo cishe wonke umuntu ezaziwayo. Lokhu akusona isimanga: it is kakhulu ezanquma inkambo yomlando Russian. Wahlupheka indlalifa yenkosi uNicholas II Tsesarevich Aleksey.
Ngisho ukuncishiselwa encane ngesikhathi esifanayo ingabangela ukopha. Nokho, ingozi hhayi kuphela ukopha ehambisana ne-kahle isikhumba ubuqotho. A usongo olukhulu ezimpilweni iziguli intraenteric, ukopha intracranial, nomphimbo, kanye ukopha emalungeni. Kulokhu, haemophilia abunakuphulukiswa iziguli zibekelwe isikhathi esithile ukwamukela esikhundleni izidakamizwa, ezingalotshwanga libhekene ukusebenza kahle eliphezulu.
Ingabe abesifazane baphathwa haemophilia?
Abantu abaningi ngephutha sikholelwe ukuthi abesifazane musa uhlushwa hemophilia. Nokho, akunjalo: wobulili fair, kakhulu, uhlushwa yilesi sifo esesabekayo. Nokho, kwenzeka kakhulu kuyaqabukela. Okuningi ngokuvamile, abesifazane abathwali isakhi predetermines sifo.
Owesifazane-thwali omunye chromosome ubulili sakhi sofuzo esikhubazayo kokuqagela incoagulability igazi. Uma kukhona genotype ka allele evelele yilesi sakhi, lesi sifo akusho ukuzibonakalisa. Nokho, uma owesifazane enezinwele umfana, okuyinto ingena sakhi sofuzo esikhubazayo, yena babonakalise hemophilia. Kodwa ukuze hemophilia ezenzeka esikhathini amantombazane kudingeka abathwali lensikazi isakhi sofuzo wayeshade nendoda nge hemophilia (kodwa ngisho ngaphansi kwezimo ezinjalo, ematfuba ukuzalwa intombazane kuyoba ulingana 25%). Ezimweni ezinjalo neze waphawula: okokuqala, isakhi sofuzo hemophilia kuyinto ngempela ezingavamile, futhi okwesibili, abantu abaphethwe yilesi sifo esiyingozi kuyaqabukela ukusinda yobudala zokuzala.
Meaning izingxenye cwaningo ubulili nokuxhumanisa
Ukuphenywa kanjani uya ifa zezici ubulili-exhumene kubaluleke kakhulu kunazo zonke esintwini. Lokhu kungenxa ngokuyinhloko yokuthi ubulili-exhumene ngofuzo izifo eziningi, kuhlanganise yingozi ukuphila komuntu. Mhlawumbe esikhathini esizayo ke uyokwazi ukwakha izindlela ezintsha nokwelapha izifo ezifana, esekelwe imiphumela ngqo okusha ngezakhi zofuzo zomuntu, okuyinto othwala i allele sokugembula. Ngaphezu kwalokho, ucwaningo olunjalo ineqhaza elikhulu ekuthuthukisweni kwe-nezinqubo uphethwe okusheshayo izifo ubulili-ezixhunyiwe. Lokhu kubalulekile ikakhulukazi izifo ezihlobene iziyaluyalu umzimba: I usheshe uqale ukwelashwa, uyophumelela bazokwazi ukufeza.
Ufuzo zisendaweni ebalulekile ekuphileni kobuntu. Phela, lokhu isayensi bangachazela kanjani umsebenzi izakhi zofuzo, kuhlanganise nalezo ezingasebenzisi izimpawu sokugembula. Kukhona iqembu izimpawu kubangelwa ifa okuyinto ubulili chromosome. Uyini ifa ubulili-exhumene? Inchazelo sithi ukudluliselwa izimpawu, okuyiwona izakhi zofuzo ezibangela, okuyinto zitholakala ku-chromosomes ocansini.
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