The Y chromosome does not cause color blindness. Colorblindness is a defective gene on the X chromosome. Females have 2 x chromosomes, thus one can serve as a backup for a defective gene. However, the Y chromosome in males is almost totally defective, thus does not have a backup.olorblindness is a defective gene on the X chromosome. Females have 2 x chromosomes, thus one can serve as a backup for a defective gene. However, the Y chromosome in males is almost totally defective, thus does not have a backup.
Kilwa Kisiwani (also known as Kilwa or Quiloa in Portuguese) is the best known of about 35 medieval trading communities located along the Swahili Coast of Africa.
Tokwe-Mukosi will be Zimbabweâs second-largest man-made reservoir after Kariba on its northern border, with the potential to irrigate about 25,000 hectares (61,800 acres) of farmland, offering a boost to sugar producers and other farmers, said Adelaide Chikunguru, a spokeswoman for South Africaâs Tongaat Hulett Ltd., which grows sugar in the region ...