Dar organizmhoi geterozigoti (Aa) geni dominanti hamesha qobiliyati pakhsh kardani geni retsessiviro nadorad. Dar bisyor mavridho dar duragahoi nasli yakum (G1) na geni dominanti va na retsessivi purra zohir nameshavand. Dar natija duragahoi nasli yakum (G1) khususiyati miyona zohir menamoyand va dar onho hissae az genhoi dominanti va retsessivi dida meshavad.
Guftan joiz ast, ki dar duragahoi nasli yakum monandi ba vujud meoyad. Masalan, az duraga kardani gulhoi rustanii shomu sahari gulash surkh (AA) va gulash safed (aa) dar nasli yakum (G1) rangi gulho gulobi (bunafsh) meshavand, yane rangi miyonai (Aa) bayni ranghoi surkh va safed paydo shuda, ranghoi hamai naslhoi G1 yakrang memonand. Baroi hamin, qonuni yakumi Mendel na qo- nuni dominanti, balki qonuni hamshaklii naslhoi gibridi nom dorad .
Merosguzorii rangi gulhoi shomu sahar dar holati dominantii nopurra: AA – surkh, Aa – bunafsh, aa – safed.
Dominanti nopurra dar tabiat hodisai vase pahnshuda buda, dar omuzishi sokhti parhoi parandagon, rangi pashmi gov va gusfandon, alomathoi biokhimiyavi dar inson dida meshavad.