Morgan chromosomal theory: inkcazelo, izibonelelo ezisisiseko kunye neempawu

Kutheni abantwana zifana abazali babo? Kutheni ezinye iintsapho twa izifo ezithile ezifana nombala ubumfama, polydactyly, hypermobility edibeneyo, abanesigulo esinganyangekiyo? Kutheni na inani izifo ezichaphazela abasetyhini kuphela kunye nabanye - madoda kuphela? Namhlanje sonke siyazi ukuba iimpendulo zale mibuzo kufuneka kucelwa yofuzo, oko kukuthi zofuzo ukuba umntwana ufumana evela kumzali nganye. Kwaye nale ngolwazi, inzululwazi mihla unyanzelekile kuTomas Hunt Morgan - genetics America. Wachaza inkqubo lokudlulisela ulwazi yemfuza kwaye iye yaphuhliswa kunye noogxa chromosomal theory welifa (idla ngokuba chromosome theory of uMorgan), nto leyo eye yaba ziintsika imizila yemfuza mihla.

History of izovela

Bekuya kuba yinto ephosakeleyo ukuba athi uThomas Morgan waba ngowokuqala ukuba babe nomdla nomba transfer inkcazelo yemfuza. Abaphandi yokuqala abaye bazama ukuqonda indima zofuzo ilifa nga kuthathelwa ingqalelo umsebenzi Chistyakov, Beneden, Rabl kwi-imi- 70-80 kwinkulungwane XIX.

Kwakungekho iimikroskopu ukuze abe nako ukubona ubume chromosome. Kwaye igama elithi "chromosome" Emva koko, kakhulu, wayengekho. Kuye yaziswa sisazinzulu waseJamani uHeinrich Valdeyr ngo-1888.

sebhayoloji German Theodor Boveri ngenxa experimenti kwabonisa ukuba kuyimfuneko ukwenzela uphuhliso eqhelekileyo umzimba oqhelekileyo inombolo yayo iintlobo zofuzo kukuthi, nokunyoluka okanye ukunqongophala ikhokelela malformations kakhulu. Ekuhambeni kwexesha, inkolelo yakhe siqinisekiswe ngokunamathelene-. Sinokuthi ukuba imfundiso chromosome T. Morgan wavuka yokuqala yakhe indawo wabulela uphando Boveri.

Qala zophando

Yolungelelwaniso lolwazi ezikhoyo kwithiyori yofuzo, ukuba ukuncedisa nokuphuhlisa ukuba ilawulwa kuTomas Morgan. Njengoko into experimenti bakhe wakhetha fly iziqhamo, kungekhona ngengozi. Yaba into ogqibeleleyo izifundo ukudluliselwa kolwazi yemfuza - chromosome ezine kuphela, ukuchuma, ubude mfutshane yobomi. Morgan waqalisa ukwenza uphando, ukusebenzisa imigca acocekileyo Iimpukane. Kungekudala wafumanisa ukuba iiseli intsholongwane ye iseti enye zofuzo, oko kukuthi 2 endaweni 4. Morgan amagqabantshintshi indlela female sex chromosome X, inkunzi - njengoko Y.

ilifa enxulumene Sex-

theory chromosome Morgan iye yabonisa ukuba kukho iimpawu ezithile ze-sex ezinxulumene. Fly, awanyakazela ngayo sisazinzulu kwenziwa amalinge bakhe, nto leyo niba elibomvu-iliso, kodwa ngenxa yemfuza yale sofuzo labemi kwakukho abantu abamhlophe amehlo, kwaye phakathi kwabo baba baninzi eyindoda ngakumbi. Isakhi, nenoxanduva umbala iimpukane iliso yenzelwe kwi X chromosome, kwi-Y-chromosome ayikho. Oko kukuthi, ngabantu besifazane ukunqumla, omnye X chromosome ene-gene mutated, kwaye linokuba ferruginous eyindoda ebusweni usikhokele siyinzala uya onxulumene emgangathweni. Indlela elula yokubonisa oku ku mzobo:

• P: XX 'x X'Y;
• _F-1: XX ', XY, X'X' X'Y.

X - chromosome sex obhinqileyo okanye sofuzo ngaphandle iliso emhlophe eyindoda; X 'abamhlophe chromosome sofuzo kwamehlo.

Ukuwuqonda iziphumo nokuwela:

• XX '- ebomvu-amehlo female gene yenethiwekhi elidlulileyo esweni. Ngenxa ubukho yesibini X-chromosome zezilimo mutated "esilala 'uphilile, kwaye ibonisa akukho phawu phenotype.
• X'Y - wesilisa-amehlo, ngubani evela X sikanina chromosome kunye sofuzo njengesi. Ngokuba enye kuphela X-chromosome phawu njengesi nto ukuvala, yaye oko kuvela phenotype.
• X'X '- chromosome ezimhlophe-eyed obhinqileyo ilifa sofuzo mutated ukusuka kumama notata. Imazi kuphela ukuba zombini X-zofuzo athwale abelungu gene yamehlo, kuya kuvela kwi phenotype.

Imfundiso chromosomal kwimfuza Thomas Morgan wachaza indlela ilifa izifo ezininzi yemfuza. Ngenxa zofuzo X chromosome ngaphezulu kakhulu kunokuba Y chromosome, kuyaqondakala ukuba unoxanduva ezininzi iimpawu ephilayo. I X chromosome ukusuka kumama ezosulela oonyana neentombi, kunye zofuzo unoxanduva neempawu zomzimba, iimpawu zangaphandle zesi sifo. Ekunye X-edityaniswe kukho ilifa Y-ezinxulumene. Kodwa Y-chromosome kuphela amadoda, kuba ukuba kwenzeka nayiphi na ukuguquka, oko kudluliswe kuphela inzala eyindoda.

Imfundiso chromosomal kwimfuza Morgan wanceda ukuqonda iipateni yokosuleleka kwezifo yemfuza, Noko ke, iingxaki ezinxulumene nonyango lwabo, ayivumelekanga kude kube ngoku.

crossover

Ngexesha sifundo, umfundi uThomas Morgan Alfred Sturtevant wafumanisa isenzeko kokuwela-over. Njengoko amalinge ezilandelayo, imidibaniso ezintsha iiseli zenzeka ngenxa ukuwela. Yaba nguye ongawuthobeliyo edityaniswe inkqubo ilifa.

Ngaloo theory chromosome T. Morgan wafumana kwenye indawo ebalulekileyo - phakathi zofuzo homologous lwenzeka yokuwela-over, kwaye rhoqo yayo umiselwa umgama phakathi imizila yemfuza.

imithetho

Nokumisa iziphumo experimenti ye sisazinzulu, iya kunika indawo olusisiseko theory chromosomal uMorgan:

1. Iimpawu zixhomekeka zofuzo eziphilayo ezihlanganiswe zofuzo.
2. Zofuzo chromosome omnye zidluliselwa kwinzala iklatshi. Le Amandla adhesion mkhulu, i ncinane umgama phakathi imizila yemfuza.
3. Le zofuzo homologous waphawula ngumkhuba kokuwela-over.
4. Ukwazi nezihlandlo yokuwela ngaphezu chromosome ethile, sinako ukubala umgama phakathi imizila yemfuza.

Imeko yesibini theory chromosomal ka Morgan kunye Morgan ngokuba umthetho.

ukuqaphela

Iziphumo zophando ezibonwe ngokunamathelene-. theory chromosome Morgan yaba impumelelo biology zenkulungwane yamashumi amabini. Ngowe-1933, ngenxa kokufunyanwa indima zofuzo yofuzo Nobel Prize yanikezelwa sisazinzulu.

Kwiminyaka embalwa kamva, Thomas Morgan wafumana Molteno Copley ukuze uphumelele kufuneka ebaleni yemfuza.

Ngoku chromosome theory Morgan ngayo kwimfuza ifundwa ezikolweni. Yena bazinikela amanqaku neencwadi ezininzi.

Imizekelo makazibandakanye ilifa floor

theory chromosome Morgan uye lubonise ukuba neempawu zomzimba zigqitywa yemfuza ebekwe phantsi kulo. iziphumo eyinqobo abe uThomas Morgan, wanika impendulo yombuzo of transfer kwezifo ezifana kubazali bakhe, Khadijah syndrome, ubumfama, isifo Bruttona.

Kuye kwafunyaniswa ukuba yemfuza yazo zonke ezi zifo zifumaneka kwi X chromosome nabafazi, ezi zifo kwenzeka alufane, njengoko chromosome esempilweni lingaliqhuba ngaphezulu eli chromosome kunye sofuzo sifo. Abasetyhini abangayaziyo loo nto, kunokuba abathwali izifo yemfuza, ezithi ke ngoko kubonakaliswa ebantwaneni.

Ngabantu, X-ezinxulumene izifo, okanye kuvela iimpawu phenotypic, ngokuba akukho sempilweni X chromosome.

Imfundiso chromosomal kwimfuza T. Morgan isetyenziswe ekuhlalutyeni imbali yosapho izifo yemfuza.