(when its hereditary) is Color Blindness recessive or dominant?

Question

for a paper for school. i cant find this info anywhere. please help

Answer 1

Color blindness (there are several types, by the way) is recessive, but it is sex linked. That means the gene is carried on the X chromosome. Men have only one X chromosome (men are XY; women are XX), so if they have the gene on the X, the trait is expressed, because there is nothing on the Y chromosome to mask it.

Answer 2

It's a recessive condition passed on the X chromosome.If you want to know more ,visit this link :
http://www.drgreene.org/body.cfm?xyzpdqabc=0&id=21&action=detail&ref=601

On wikipedia there is alot information about the Color Blindness it self.

Answer 3

Red-gren colour blindness is called a sex-linked recessive.

This gene is carried on the X chromosome. (Remember females have XX and males XY).
Because it is sex linked recessive many more males will be colour blind that females.

Example:( If we say b=colour blindness and B is normal and as it is carried on the X chromosome we put it liek this Xb or XB)
Here are the possible genotypes and phenotypes options for male and females
normal female XB XB (not colourblind)
carrier female XB Xb (not colourblind)
affected female XbXb (colourblind)

normal male XB Y (not colour blind)
affected male Xb Y (colourblind)

AS you can see its much easier for the males to be affected by the gene as they only need 1 copy and they will get the condition.
Females needs both parents to have the gene to get it, which is genetically much harder.
FYI: If a male has the condition it has been passed from his mother (as he will recieve the Y chromosome from his father, which has nothing to do with colour blindness). Her father would have almost certainly had the condition as well and she was a carrier.

Answer 4

Its recessive, but its also sex-linked... passed down on the X chromosome

Answer 5

it is recessive