Color blindness is a sex-linked trait. As such if a child is color blind, we can be assured that the child's genotype includes: Select one: a. a dominant gene on the X chromosome inherited from his mother b. a recessive gene on the X chromosome inherited from his mother c. a dominant gene on the X chromosome inherited from his father d. a recessive gene on the Y chromosome inherited from his father

The correct answer is b. a recessive gene on the X chromosome inherited from his mother.<br /><br />Color blindness is a sex-linked trait that is carried on the X chromosome. Since males have only one X chromosome, they are more likely to be color blind if they inherit the recessive gene for color blindness from their mother. Females, on the other hand, have two X chromosomes, so they would need to inherit two copies of the recessive gene (one from each parent) to be color blind. If a child is color blind, it means that they have inherited the recessive gene on their X chromosome from their mother.