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.
Skoki Lodge is a National Historic Site situated in a beautiful high alpine region in Banff National Park. The 11 km (6.8 mi) trek from Lake Louise to the Skoki Valley makes Skoki Lodge an ideal destination for hikers and skiers of all levels.