The answer is the Xist RNA, x-inactive specific transcript is a gene on the X chromosomes of the placental mammals that acts as a major effector of the X inactivation process. Non coding RNA is a functional RNA molecule that is transcribed from DNA but not translated into proteins.
Polygenic inheritance is determined by multiple Genes <span>located at different loci on different chromosomes.
Polygenic inheritance happens when an individual posses quantitative traits that become a variation compared to the parent's traits.
This phenomenon happens due to the combination of two or more genes that resulted in the characteristics that considered as the combination of both parents' characteristic.
</span>