Why are there more men than women with colorblindness?

Answer 1

Because the genes that affect colorblindness are only found on the Y chromosome.

Answer

I am a woman who is red--green colorblind. The trait is carried on the X chromosome. Males receive an X chromosome from their mother and a Y from their father. If the X carries the trait of colorblindness, the male will be colorblind. Females need to receive two defective X chromosomes to be colorblind, one from their father and one from their mother. If a women has only one defective X chromosome, she will be a carrier of the trait. My father was red-green colorblind and so was my mother's father, making my mother a carrier of the trait, although she is not colorblind herself. I have two sisters who are not colorblind, as they each received a non-defective X chromosome from my mother. I knew before my son was born that he would be red-green colorblind, as the X chromosome he received from me carried the trait.

Answer 2

Because it is a recessive gene on the X chromosome of the sex-related X-Y pair. Every man who gets the recessive gene from his mother will be color blind. For a woman to be color blind, she must get the recessive gene from both her mother and her father.

Answer 3

More men are color blind than women because the recessive gene for color blindness is carried by women on one of their X chromosomes. And since they have two X chromosomes, the recessive trait is less likely to be expressed. Since men have an X and a Y chromosome, which is shorter, if a mother passes on her X chromosome with the trait of color blindness, her son will have no corresponding gene on his Y chromosome from keeping it from being expressed. So men are color blind more often than women.

Answer 4

The gene for the most common form of color blindness is only present on the X chromosome, and males are born because of " XY" chromosomes while females are born because of "XX". Therefore when the X chromosome on males mutates itself it has no backup "code" to fix the mutation while females have another set of X chromosomes.