A colour blind man marries the daughter of a colour blind person. Then in their progeny a. None of their daughters are colour blind b. All the sons are colour blind c. All the daughters are colour blind d. Half of their sons are colour blind

Sure! Here are the step-by-step solutions: Let's assume that the father is colorblind and the mother is a carrier. We know that the mother carries one normal X chromosome and one X chromosome with the recessive gene for color blindness. When the mother has a child, there is a 50% chance that the child will inherit the normal X chromosome and a 50% chance that the child will inherit the X chromosome with the recessive gene for color blindness. If the child inherits the normal X chromosome, they will not be colorblind. If the child inherits the X chromosome with the recessive gene for color blindness: - If the child is a girl, she will be a carrier like her mother. - If the child is a boy, he will be colorblind because he only has one X chromosome and it has the recessive gene for color blindness. Therefore, if a colorblind father and a carrier mother have children: - There is a 50% chance that their sons will be colorblind. - There is a 50% chance that their daughters will be carriers. And that's the solution!