Kodi pali kusiyana kotani pakati pa dzira ndi umuna?

Monga momwe tikudziwira, maselo a kugonana, mosiyana ndi a somatic, omwe ali mbali ya ziwalo zosiyanasiyana ndi machitidwe, amasiyana, choyamba, mwachinsinsi chawo, chomwe chimaphatikizapo kuberekana kwa mibadwo yotsatira. Ndicho chifukwa chake majini awo amawoneka ndi ma chromosomes, i.e. theka (23 chromosomes). Pa nthawi yomweyi mwana wamwamuna wam'tsogolo amapeza zosiyana ndi amayi ndi abambo. Tiyeneranso kukumbukira kuti kuchokera pa chiwerengero cha chromosomes chiwerengero cha chromosome imodzi yokha chimayambitsa kugonana kwa mwanayo, chifukwa 22 ndi autosomes. Tiyeni tiwone bwinobwino maselo ogonana, ndikuuzeni za kusiyana pakati pa selo lachiwerewere, dzira, kuchokera ku umuna wa umuna.

Kodi ndi makhalidwe ati a maselo a amuna?

Choncho, spermatozoa, poona kuti ayenera kukhala ndi maulendo apamwamba chifukwa cha umuna, ndi maselo ang'onoang'ono, omwe thupi lawo limapangidwira. Umuna, mosiyana ndi ovum, ulibe cytoplasm yambiri. Limakhala ndi gawo lokhala ndi mtima lomwe limatchedwa mutu, ndi flagellum (mchira), yomwe ndi mbali yake yoyendayenda. Kuchokera ku zomwe zimatchedwa subcellular mu spermatozoon, pali mitochondria yomwe imapereka mphamvu zofunikira kuti kayendetsedwe, acrosomal vacuole (yomwe ili ndi michere yotaya ma envulopu ya dzira lopsa), yomwe imakhala yochepa kwambiri. Nthenda yonse ya spermatozoon ili pafupifupi 60 μm, yomwe mchira uli 55 μm.

Pamene mutasiya kugonana kwa mwamuna, nyamayi, umuna ndi wamng'ono, mwachitsanzo, Iwo alibe maulendo, koma amapangidwa mokwanira. Choncho, alibe mphamvu zothira manyowa. Kugwiritsa ntchito maselo amtundu wamwamuna kumachitika m'dongosolo la vas deferens.

Ndi mbali ziti za kapangidwe kawo zomwe zimayimira kachirombo ka kachirombo kaakazi?

Selo la majeremusi ya atsikana, dzira, mosiyana ndi spermatozoon, ndilokulukulu ndipo silikuyenda. Miyeso yake imadza ma microns 100-200 mwa anthu. Izi ndizo chifukwa chakuti ndi dzira lomwe liri yosungiramo trophic connections, zomwe zimangokhala zofunikira kuti chitukuko cha mimba chiyambike. Komanso, nyumba zambiri zopangidwa ndi cytoplasmic zimapangidwira popanga mibadwo yoyamba ya maselo ammabonioni - blastomeres.

Dzira la dzira, mosiyana ndi spermatozoon, limadziwika ndi nkhono yaikulu, yomwe euchromatin (nucleoprotein kumalo oyandikana ndi pakatikati mwa pathupi, yowonongeka, yomwe imayambitsa kusinthidwa kwa chibadwa) imakhala yaikulu komanso imakhala ndi cytoplasm yambiri. Pa nthawi yomweyi mitochondria imakhala yochepa kwambiri, yomwe imayambitsidwa ndi maselo achiwerewere. Ndiyeneranso kuzindikira kuti maselo amtundu waumunthu sangakhalepo okhaokha. Kupatulapo kungakhale, mwinamwake, gawo loyambirira la mapangidwe awo, pa siteji ya ogony. Kawirikawiri, ma ovules ali pafupi kwambiri ndi maselo amtunduwu, omwe kwenikweni amachititsa kulumikizana ndi kachilombo kozungulira pa selo lililonse lachikazi. Kuvuta kumeneku kunkatchedwa mtundu wa ovarian follicle. Mapangidwe ake ndi ovuta pochita oogenesis .

Kusiyanasiyana konse kwa dzira kuchokera kwa umuna sizingatheke patebulo limodzi, kotero awa ndi maselo awiri osiyana.

Kodi kusiyana kwakukulu pakati pa majeremusi ndi chiyani?

Atanena za mazira omwe ali osiyana ndi spermatozoa ndi chifukwa chake, kufotokozera mmwamba, ndikufuna kulemba kusiyana kwawo kwakukulu. Zina mwa izo pali:

• kukhazikitsa chromosome (mu spermatozoa - X chromosome, mu oocyte - U);
• kusiyana kwa nyukiliya-cytoplasmic chiŵerengero (mkulu mu spermatozoon, otsika mu dzira);
• kukula ndi mawonekedwe (aakulu ndi okonzedwa motsutsana ndi aang'ono ndi ochepa);
• umuna uli ndi chiwalo choyendetsa.

Choncho, zikhoza kunenedwa kuti kusiyana kwakukulu kwa spermatozoon kuchokera ku dzira kuli mu kapangidwe ka zinthu, chifukwa cha kufunika kwake kwa chilengedwe.