Kalli nassi da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar nassi: Passage: Kowane sarkar mai nauyi tana da yankuna biyu, yankin da ba a canzawa da kuma yankin da ba a canzawa ba. Yankin da ba a canzawa ba iri ɗaya ne a cikin dukkan ƙwayoyin cuta na isotype guda ɗaya, amma ya bambanta a cikin ƙwayoyin cuta na isotypes daban-daban. Sarƙoƙi masu nauyi γ, α da δ suna da yankin da ba a canzawa ba wanda ya ƙunshi yankuna uku na Ig (a cikin layi), da kuma yankin jingina don ƙarin sassauci; sarƙoƙi masu nauyi μ da ε suna da yankin da ba a canzawa ba wanda ya ƙunshi yankuna huɗu na immunoglobulin. Yankin da ke canzawa na sarkar mai nauyi ya bambanta a cikin ƙwayoyin cuta da ƙwayoyin B daban-daban ke samarwa, amma iri ɗaya ne ga duk ƙwayoyin cuta da ƙwayoyin B ɗaya ko ƙwayoyin clone B ke samarwa. Yankin da ke canzawa na kowane sarkar mai nauyi yana da kusan amino acid 110 kuma ya ƙunshi yankin Ig guda ɗaya
110 da kuma