Nasaba gādo

Irin wannan abu a matsayin gado na halaye, yadu karatu a itatuwa aure. Wannan shi ne bayanin kama da zũriyarmu, kuma iyaye. Yana da ban sha'awa cewa wasu daga cikin manifestations ãyõyi ake gaji tare. Wannan sabon abu ne da aka bayyana a cikin daki-daki, a karon farko da wani masanin kimiyya T. Morgan, shi zama da aka sani "nasaba gādonsa." Za mu yi magana game da shi.

Kamar yadda aka sani, kowane jiki yana da wani yawan kwayoyin halittu. Chromosomes kamar yadda a cikin wannan hali - kamar yadda mai tsananin iyaka yawan. Don kwatanta, da lafiya jikin mutum yana da 46 chromosomes. Gene kamar yadda shi ne dubu sau more. Alkalin da kanka: kowane gene ne alhakin wani musamman hali, bayyana a cikin bayyanar wani mutum. Babu shakka, da yawa daga cikinsu. Saboda haka, za mu fara magana a game da gaskiyar cewa da dama genes ake sarrafa to guda chromosome. Wadannan kwayoyin halittu da ake kira hadin kungiyoyin da kuma ayyana nasaba gādo. Irin wannan ka'idar ne da muhimmanci ga kimiyya al'umma na dogon lokaci, amma kawai T. Morgan ya ba ta definition.

Ba kamar gādon genes cewa ana sarrafa a cikin daban-daban nau'i-nau'i daga wannan chromosome, nasaba gado sa da samuwar digeterozigotnoy mutum na kawai iri biyu gametes, da maimaita da jerin mahaifa genes.

Tare da wannan, akwai gametes, da hade da kwayoyin halittu da ya bambanta da da iyaye chromosomes. Wannan sakamakon shi ne sakamako da crossover - wani tsari wanda muhimmancin a halittar jini da wuya a overestimate, domin shi damar da zuriyata ga sami wani iri-iri cututtuka daga iyaye biyu.

A yanayi, akwai iri uku gene gādo. Domin sanin abin da irin shi ne muhimmi a wannan biyu daga gare su, amfani da gwajin giciye. A sakamakon haka, shi ne tabbatar da samun daya daga cikin uku zabin kasa:

1. An m gādo. A wannan yanayin, da hybrids ne daban-daban daga juna da kuma daga iyayensu a cikin bayyanar, a cikin wasu kalmomi, a sakamakon, dole mu 4 daban-daban phenotypes.

2. Full mannewa genes. ƙarni na farko na hybrids aka samu ta hanyar su tsallaka da iyayentaka mutane ne guda phenotype indistinguishable iyaye da juna.

3. Yankin mannewa genes. Kamar yadda a farkon yanayin, a lokacin da ya haye ya jũya sa 4 daban-daban phenotypes. A lokaci guda, duk da haka, samuwar sabuwar genotypes cewa su ne gaba daya daban-daban daga cikin iyaye asusu. Shi ne a cikin wannan harka a gamete samuwar tsari tsarè crossover da aka ambata a sama.

Haka kuma an gano cewa, da karami da nisa tsakanin gaji genes a cikin parental chromosome, da mafi kusantar su cika nasaba gādo. Haka kuma, da m baya aka shirya, da m mararraba na faruwa a lokacin meiosis. A nisa tsakanin kwayoyin halittu - wani factor cewa da farko kayyade yiwuwa nasaba gādo.

Dabam shi wajibi ne a yi la'akari da nasaba gado alaka da jima'i. Jigon shi ne kamar a cikin embodiment tattauna a sama, duk da haka, sun gaji genes a cikin wannan harka shirya a jima'i chromosomes. Saboda haka, don magana game da irin wannan gado mai yiwuwa ne kawai a yanayin saukan dabbobi masu shayarwa (mutum daga gare su), da wasu dabbobi masu rarrafe da kwari.

Shan la'akari da cewa XY - a sa na chromosomes, m to da ɗa namiji, da kuma XX - mace, mun lura cewa duk da babban siffofin waxanda suke da alhakin lamarinsa na jiki, suna located a kan chromosome ba a cikin genotype na kowane kwayoyin. Hakika, muna magana ne game da X - chromosome. A mãtã mai yiwuwa ne su kasance ba duka biyu recessive da rinjaye genes a chromosomes. Maza ma iya gada daya kawai wani zaɓi - wato, a gene bayyana kanta a cikin phenotype ko ba.

Nasaba gādo saboda jima'i, sau da yawa ji a cikin mahallin da cututtuka waxanda suke da peculiar to shi maza, yayin da mata ne kawai yan dako na:

• hemophilia,
• makanta.
• Nai Han - Alex ciwo.