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 usually have problems identifying reds and greens, too. The most severe form of color blindness is achromatopsia.A person with this rare condition cannot see any color, so they see everything in shades of gray. Achromatopsia is often associated with lazy eye, nystagmus (small, jerky eye movements), severe light sensitivity, and extremely poor vision.See: X-linked recessive) 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. It is used to treat rheumatoid arthritis, among other conditions.