|Picture taken from here|
I’m sure you have all seen pictures like the one to the left before, it’s one of the many pictures designed to be a test for color blindness. Color blindness is a relatively common problem and I’m sure we all have at least met someone that is color blind. You have probably also heard that color blindness is a genetic disorder that effects mostly males because it is a sex linked trait. The normal X chromosome carries a protein that is used in color detection, without it the person is color blind. As long as the person has one chromosome that carries the protein the person isn’t considered color blind. However if you have read my previous posts I have told you that one of the X chromosomes in females inactive itself. This means that it’s not always as straight forward as you might initially think. A heterozygous (meaning that they have one effected chromosome and one normal one) female could be partly colorblind.