The preliminaries to Portugalâs formal colonial rule in Africa are extensively explored here (in a work first published in 1969) by the writer generally considered to be the doyen of foreign scholars of Portuguese expansion. Castelo, ClÃ¡udia.
Description: The two genes that produce red and green light-sensitive proteins are located on the X chromosome. Mutations in these genes can cause color blindness. Color blindness is a common inherited sex-linked disorder that affects a person's ability to see or recognize certain colors.Eight to ten percent of all males and one half of a percent of all females are color-blind.Keywords: sensitive proteins,chromosome mutations,color blindness,chromosome x,x chromosome,sex linked disorder,genes,females,colors.utations in these genes can cause color blindness. Color blindness is a common inherited sex-linked disorder that affects a person's ability to see or recognize certain colors.
5. Xerophthalmia or night blindness is characterized by blindness due to the poor growth, dryness and keratinisation of epithelial tissue or chronic eye infection. The cause of this disease is attributed to the deficiency of Vitamin A in the body.In worsened situations, night blindness can aggravate to complete loss of vision. The safest way to enhance the Vitamin A levels in the body is by consuming natural food sources like carrots, green and leafy vegetables, cantaloupes etc.he deficiency of niacin is also accompanied by a short supply of the amino acids, tryptophan and lysine or the excessive presence of lysine in the body. Foods enriched with niacin are tuna, whole grains, peanuts, mushrooms, chicken etc. These should be consumed regularly to ward off this disease.