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.
Industrial or environmental chemicals such as carbon monoxide, carbon disulphide and some containing lead can also cause colour blindness. Age â in people over 60 years of age physical changes can occur which might affect a personâs capacity to see colours.