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.
This is the most common type of color blindness. If a different pigment is missing, you may have trouble seeing blue-yellow colors. People with blue-yellow color blindness often have problems seeing reds and greens, too. The most severe form of color blindness is achromatopsia. This is a rare condition in which a person cannot see any color, only shades of gray. Most color blindness is due to a genetic problem. About 1 in 10 men have some form of color blindness. Very few women are color blind. The drug hydroxychloroquine (Plaquenil) can also cause color blindness.