Le chromosomal theory kwimfuza

Amathemba noloyiko, ngubani na oya kuba kufana lo mntwana engekazalwa, nakweyiphi na abazali ilifa ingqondo yaye yintoni ngeempawu uya ingachazwa kusoloko kunye oomama, abazali noomawokhulu lonke lokukhulelwa kwabo ngexesha ebuntwaneni. Kodwa kuxhomekeke abazali kakhulu - apha izenzo chromosomal theory kwimfuza, zofuzo ... icala.

Yinto eyaziwayo ukuba zofuzo labantu zofuzo zahlulwe iintlobo ezimbini - autosomes kunye zofuzo ngesondo. Ezinye iimpawu genetic ezinxulumene ngesondo kwabantu, ngoxa inxalenye eseleyo autosomes eziqulathe ulwazi yemfuza. A isakhi icandelo DNA equlathe iqela nucleotides kunye nolandelelwano nto leyo ulwazi yemfuza, nto leyo ekhokelela kuseko iimpawu ezithile eziphilayo. Bona kweentlobo ezimbini - lisalawula kunye sofuzo. Indlela ukurekhodwa ulwazi yemfuza ezilawula imfuza ababandakanya ulandelelwano nucleotide, kwaye sibizwa ikhowudi yezofuzo.

Kwaye ke iqanda kunye amadlozi ekukhulelweni bazise ngababini 23 eziyimfuneko ukuze kugqitywe ikhowudi foetal yemfuza. Nalapho ke wabeka iliso umbala umntwana, isakhiwo yaso emzimbeni, le utyekelo ezikhethekileyo kunye notyekelo. Eli linani magic 23 kuthetha ukuba umama kunye notata wegqitha nesiqingatha kuphela ikomkhulu labo yemfuza - ukuba akunakwenzeka ukuchaza. Oko kukuthi, uphawu ngamnye umntwana lowo ngenxa yokuwela izinto ezimbini umzali. 22 autosomes zibaliwe ngobukhulu. nezinye zofuzo ababini, X kunye Y, zezona zofuzo ngesondo. Le ndlela zofuzo yabantu ezicwangciswe ngokwezibini kwaye kuthiwa karyotype.

Yofuzo, okubamba kwinkqubo lokuba zikhe indima ebalulekileyo, i impahla esisiseko lwezinto eziphilayo kunye neempawu zabo - morphological, ukusebenza komzimba, kwemichiza okanye ngokwasengqondweni. Imithetho esisiseko kwimfuza zaye mawuqulunqwe 1866, Mendel, ekuthiwa ngunozala nenzululwazi ngayo imizila yemfuza. ukuba Iipropati ngamnye ezixhomekeke izinto ezithile yemfuza (genes kamva wafumana igama), kukwenziwa gametes share kwaye inxaxheba kwezichumiso wabo wathi. Ngenxa yoko, abantu bazalwa kunye imidibaniso ezahlukeneyo yemfuza zooyise yomama.

umsebenzi Mendel waqhubeka, lo isazinzulu American Thomas H. Morgan. chromosomal lakhe theory kwimfuza esekelwe kwiziphumo zophando iimpukane-drozdofil. Wagqiba ukuba izakhi kwi zofuzo ezahlukeneyo ilifa ngokuzimeleyo. Ukudityaniswa zofuzo ngexesha neqanda ibaluleke kakhulu ekudluliseni neempawu zamafa. isibini ngasinye iqulethe zemfuza ezifanayo kunye uhlobo elula ilifa esinxulunyaniswa enye iperi yemfuza.

Ukongeza, ithiyori chromosome amabango ilifa kanye zofuzo kunokwenzeka debonding. Ukwehluleka inani eqhelekileyo zofuzo iiseli kwaye ngunobangela ophambili zezifo yemfuza womntu. Abanye ukungaqheleki chromosome ungabi sisizekabani sifo carrier, nangona kusenokwenzeka ukuba kungakhokelela ukuzalwa komntwana ezinenani okungaqhelekanga zofuzo (chromosome syndrome). Le ngezifo ingavezwa kubekho inani eliphunguliweyo zofuzo, ubukho leekopi, ulwalathiso umva okanye uthimbo inxenye chromosome kwenye chromosome. Uninzi zofuzo yokuba ngokwaneleyo, kwaye akukho negalelo kuphuhliso loluntu. Ngaphandle ke aberrations chromosomal ukuba Ndiyijike isakhiwo zofuzo.

Uphando Morgan bakaThixo akulambathanga. chromosomal theory kwakhe kwimfuza siqinisekiswe yaye, okona kubaluleke kakhulu, uphuhliso ngakumbi ekufundeni yohlobo sofuzo.