Development kunye nesakhiwo gametes

Indlela emayenziwe ngayo into eyindoda, gametes ababhinqileyo ikhokelela ukuzaliseka umsebenzi wabo ibalulekileyo - yokuphumeza nokuzala okuzala. Kuyinto ayinikiwe kubameli bazo zombini izityalo kunye nezilwanyana. iimpawu noshowo iiseli lwegciwane eza kuxutyushwa kwinqaku lethu.

Gametes: ukuzalana lwesakhiwo kunye nokusebenza

iiseli ezizodwa yenzelwa inkqubo yokuzala okuvelisa zibizwa ngokuba gametes. iiseli indoda nenkazana sex - sperm kunye namaqanda - ke haploid, okt iqela elilodwa zofuzo ... Loo isakhiwo inika gametes kweejini kwento ephilayo, oluthi luqokelelane yi naziphi zabo. Yena a diploid, okanye kabini. Ngoko ke, isiqingatha ulwazi yemfuza ephilayo ufumana kunina, kwaye enye inxalenye - ukusuka kuyise.

Nangona ukufana, isakhiwo sex iiseli izityalo kunye nezilwanyana ngeendlela ezininzi ezahlukeneyo enye kwenye. Oku kusebenza ngokukodwa kwiindawo ezithile nokudaleka. Ngoko ke, kwisidoda angiosperms akhiwe anthers of stamens, ngelixa iqanda - in isizalo le pistil. izilwanyana Multicellular imizimba ezikhethekileyo - endlaleni, leyo ukuyilwa gametes: ova - in zamaqanda kunye neeseli amadlozi - kule amasende.

Inkqubo ye gametes ezenza

Ubume kunye nophuhliso kweeseli intsholongwane ixhomekeke ikhondo gametogenesis - inkqubo ukubunjwa kwabo, nto leyo ethatha kuqhubeka ngokwezigaba eziliqela. Ngethuba lesigaba ukuvelisa ezi gametes zaseprayimari lahlulwe izihlandlo eziliqela mitosis. Ngexesha ilondoloza iseti kabini zofuzo. Xa abantu ngokwesini, le nqanaba uye iiyantlukwano zalo. Ngoko ke, izilwanyana eyindoda, yena iqala lokufikisa kwaye sihlala kude ukwaluphala. Kwicandelo sabafazi iiseli lwegciwane ekwakuphila kwenzeka kuphela ngexesha Palsy yosana olungekazalwa. De lokufikisa, bahlala aleleyo.

Inqanaba lokukhula oku kulandelayo. Kweli xesha gametes zaseprayimari bekhula ngobukhulu, phindana kwenzeka (kabini) DNA. Inkqubo ebalulekileyo kwakhona ukugcinwa kwezondlo, kuba baya ezifunekayo iyantlukwano ezilandelayo.

Yinkalo yokugqibela gametogenesis kuthiwa kwisigaba lokukhula. Xa indlela yayo iiseli zesini zaseprayimari ndohlulahlule meiosis - meiotic. isiphumo salo ezine iiseli haploid zivela diploid lokuqala.

spermatogenesis

Ngenxa yoko, ukuyilwa gametes eyindoda, t. E. Spermatogenesis wambumba isakhiwo ezine ncam yaye ngokupheleleyo. Bona bayakwazi umgquba. Ubume bale iiseli inkunzi lokuzala, ngakumbi ngqo, osemqoka wayo imbonakalo apha naphaya ezithile. Nangakumbi, lo msila, leyo ukulawula intshukumo gametes eyindoda. Le nkqubo ithatha indawo kwisigaba sokugqibela i ukuyilwa ezongezelelweyo, nto leyo luphawu kuphela inkqubo spermatogenesis.

ovogenesis

Ulwakhiwo female iiseli intsholongwane, kwakunye inkqubo nokudaleka (oogenesis) kukho inani lemisebenzi esemqoka isici. Kunye ekukhuleni oocytes ngexesha elizayo kukho icytoplasm meiotic edyokhweni isasazwe phakathi iiseli. Kuphela enye kuzo ngenxa yokufumana iqanda ekwaziyo akhokhelele kubomi elizayo. Abanye abathathu eziguqulelwe kwi ithole yesikhokelo kunye isiphumo itshabalele. Intsingiselo begazi yale nkqubo kukunciphisa inani aqolileyo, nako umgquba gametes ababhinqileyo. Kuphela phantsi kwalo mqathango, kuphela iqanda uyakwazi ukufumana imali efunekayo kwezondlo kubaluleke kakhulu kuphuhliso lwexesha elizayo eziphilayo. Ngenxa yoko, ngelo xesha, xa umfazi ekwaziyo engenabantwana, ukukwazi ukwenza inani leeseli malunga 400 ngesondo. Ngoxa madoda nani eziliqela amakhulu ezigidi.

Ubume bale iiseli lwegciwane oyindoda

amadlozi ziiseli ezincinane kakhulu. ubukhulu yabo akuyona micrometers ezimbalwa. Uhlobo zobukhulu ezinjalo, Kakade ke, uyahlawulwa inani labo. Ubume iiseli zesini samadoda umzimba uneempawu zawo.

Ngqamanisa ਸੀਲ iqulathe intloko, intamo kunye nomsila. Nganye kwezi ndawo yenza imisebenzi ethile. Intloko uba organelle esisigxina cellular of eukaryotes - i kernel. Yeyona yenethiwekhi lolwazi yemfuza eziqulathwe iimolekyuli DNA. Inika undoqo yokudluliswa nokugcinwa kwezinto zamafa. Ilungu yesibini intloko isidoda lo acrosome. Le nesakhiwo elungisiweyo Golgi ezintsonkothileyo yabela enzayim ezithile ekwaziyo ukuchitha iqokobhe eqandeni. Ngaphandle kwalo, inkqubo ifakwe akunakwenzeka. Ezi organelles yentamo mitochondria, nezinika intshukumo komsila. Kule nxalenye sperm kwaye centrioles. Ezi organelles zidlala indima edibanise ebalulekileyo ukubunjwa ngexesha cleavage ukuba iqanda. Umsila yenzala kwakheka microtubules ukuba usebenzisa mitochondria amandla zinika intshukumo ye gametes eyindoda.

Ubume beqanda

Iiseli lwegciwane Female makhulu kakhulu ngamadlozi. ububanzi yabo ezanyisayo kukuba ukuya ku 0.2 mm. Kodwa inani elifanayo Crossopterygii yi-10 cm, ngoxa porbeagle -. Ukuze 23 cm nshita iiseli sex iqanda eyindoda ayinakutshintshwa. Zinelungelo imilo ngeenxa zonke. Xa kukho icytoplasm ezi seli iqulathe isixa esikhulu loovimba elondolozwe izondlo ngohlobo egg sac. Ukongeza DNA ezingundoqo ithwele ulwazi yemfuza, kukho enye nucleic acid - RNA. Iqulethe ulwazi malunga isakhiwo iiproteni ezinkulu kumzimba elizayo. Le sac beqanda abanokufakwa kolwabelo olungalinganiyo. Umzekelo, i-Amphioxus nguye embindini, neentlanzi ithatha up phantse yonke umphezulu, ihlaba ngumongo kwaye kukho icytoplasm ukuya kwenye nezibonda esiseleni. Ngaphandle kweqokobhe iqanda lukhuselwe: sac, kunye elubala engaphandle. Ukuba wavala acrosome yentloko isidoda ukuphumeza inkqubo ifakwe.

iintlobo kokukhulelwa

Ubume kunye umsebenzi kweeseli lwegciwane banoxanduva lokuphunyezwa kwenkqubo neqanda - ukudityaniswa gametes. Kule nkqubo, izinto yemfuza gametes kukhatshwa ukuya engundoqo enye, kwaye kwasekwa elilodwa. She is seli yokuqala ephilayo entsha.

Kuxhomekeka kwindawo yokwaluka yenkqubo ahluka langaphandle (lwangaphandle) kunye lwangaphakathi isichumiso. Uhlobo lokuqala lwenziwa komzimba iimpuku ababhinqileyo. Oku kudla ngokwenzeka kokusingqongileyo emanzini. Imizekelo eziphilayo apho kukho kwezichumiso yangaphandle, abangamalungu iklasi yeentlanzi. namankazana abo amaqanda emanzini apho inkunzi yayo zasela fluid ZakwaLizwi Zehlabathi. Inani amaqanda izilwanyana ezifana ukuya ku amawaka, apho iphila kwaye ukhula na abantu kangaka. Inkoliso yabo zidliwa izilwanyana zasemanzini. Kodwa zonke ezanyisayo luphawulwa kwezichumiso lwangaphakathi, olwenzeka ngaphakathi emzimbeni ababhinqileyo kunye ngoncedo amalungu ezizodwa copulative eyindoda. Inani amaqanda ilungele ukuchumisa, incinci.

Ubume bale inkunzi nemazi okuzala kwinkqubo okuzala izityalo yahluke kakhulu ukusuka kuloo zezilwanyana. Ngoko ke gametes lokuhlanganisa inkqubo eyahlukileyo. iiseli zesini samadoda izityalo abanayo nomsila kwaye akanako ukuhamba. Ngoko ke, ukufaka isichumiso owandulelayo uvuvuzelo. Le nkqubo yokunikezela umungu ukusuka anther ukuya stamens ibala. Le kwenziwa ngumoya, izinambuzane okanye abantu. Iimvelaphi ngendlela phezu ibala enjalo, bewuhlisele amadlozi intsholongwane ityhubhu inxalenye yayo eyandisiweyo asezantsi --maqanda. Kukho iqanda. Xa gametes ekudibaneni kuyilwa umbungu imbewu.

Ingcamango parthenogenesis

Ubume bale iiseli lwegciwane, amabhinqa ingakumbi, yenza kunokwenzeka enye iintlobo ezininzi engaqhelekanga yokuzalana okuzala. Libizwa ngokuba parthenogenesis. kubume bayo lomzimba ilele kuphuhliso abadala kweqanda unfertilized. Le nkqubo iqatshelwe umjikelo wobomi intlanzi Daphnia apho isizukulwana ngokwesondo kunye parthenogenetic enye. Iseli Female lokuzala iqulethe izondlo ngokwaneleyo ukuze kubekho ubomi obutsha. Noko ke, kukho xa kungekho parthenogenesis zizifundo ezintsha zolwazi yemfuza, yaye ngoko, imbonakalo weempawu ezintsha kangangoko kunokwenzeka. Nangona kunjalo parthenogenesis sibaluleke yebhayoloji ngokuba lenza inkqubo ukuzala kunokwenzeka ngaphandle phambi abantu besini esahlukileyo.

Isigaba ukuba sexesheni

Xa iiseli yintsholongwane imazi ayisoloko alungele ukuchumisa, kodwa kuphela xa ezithile izigaba zomjikelo sexesheni. Ngethuba lale nkqubo komzimba emzimbeni kwenzeka utshintsho cyclically rhoqo imisebenzi uhlelo zokuzala. Le nkqubo kulawulwa yinkqubo humoral. Ubude bexesha lo mjikelo ziintsuku 21-36 ezinomyinge 28. Ixesha angohlulwa ngezigaba ezithathu. Ngenyanga yokuqala (sexesheni) elisuke malunga iintsuku zokuqala-5, le endometrium yaliwe. Oku kulandelwa komsipha kwemithambo yegazi. 6-14 mini aba phantsi kwempembelelo yebhinqa follicle limi apho iqanda ukuvuthwa. Ingaphakathi isibeleko ngeli thuba iqalisa kwakhona. Esi sisigaba essence poslemenstrualnoy. Ukususela th 15 ukuya 28 th ka ukuyilwa inyama okunamafutha nokuqina - le luteum corpus. Sisebenza indlala ezidalwe yethutyana ukuba ikhupha iincindi zamadlala zinqanda ekukhuleni zoboya. Kweli xesha ukusuka 17 th ukuya 21 ngosuku wasekwayo amathuba ifakwe lelona liphezulu. Ukuba oku akwenzeki, iseli sex ibhuqiwe kwaye inwebu yangaphakathi ithe atyabukile umva.

Yintoni ovulation

Ngosuku 14 sexesheni isakhiwo iiseli ababhinqileyo lokuzala utshintsha kancinci. Iqokobhe iqanda waphula follicular kwaye kukhululwa isizalo ukuya tube Imibhobho. Kwaba khona ukuba ligqibe ekukhuleni kwayo. Le nkqubo ibizwa ngokuba ovulation. Le ixesha ebaluleke kakhulu, ngexesha apho isibeleko ofumana ukukwazi ukuba amkele iqanda.

Chromosome iseti gametes

Amaqanda kunye amadlozi babe iseti enye inkcazelo yemfuza. Ngokomzekelo, iiseli zesini zabantu eziqulathe 23 zofuzo, kwaye elilodwa - 46. Xa intlanganisela gametes isiqingatha zofuzo ephilayo ufumana kunina, yaye inxalenye yesibini - ukusuka kuyise. Oku kusebenza phantsi. Phakathi zofuzo autosomes eziBekekileyo kunye isibini ngesini. Bona otyunjwe Latin. Xa abantu, iiseli ababhinqileyo ziqulathe zofuzo ezimbini ngesondo ezifanayo, ngoxa abantu - ezahlukeneyo. iiseli intsholongwane ibe omnye wabo. Ngoko ke, isini umntwana uxhomekeke ngokupheleleyo emzimbeni inkunzi uhlobo zofuzo ukuba ithwale ukuchuma kwakho.

Umsebenzi kweeseli lwegciwane

Ubume bale iiseli abangamabhinqa lokuzala, kwakunye namadoda, ukuba ezihlangene nemisebenzi eziyenzayo. Njengenxalenye yenkqubo zokuzala, enze umsebenzi ukuzala okuzala. Ngokungafaniyo maqanda, eliphethe ukuthembeka kolwazi yemfuza kwento ephilayo, ukuzala kuvumela nokudalwa izinto ezintsha. Oku ngumqathango oyimfuneko ukwenzela iziganeko adaptation, ngoko ke yonke ubukho eziphilayo.