Question

Bob is color blind, but he knows that neither of his parents were color blind. He is wondering if he received the gene for color blindness from his mother, his father, or both of his parents. what would you tell Bob ? show a Punnett square to prove your answer!

Answer 1

The color blindness would be from his mother, since it is located in the X chromosome, and since his father is not color blind, and he only has one X chromosome, it could not come from him, but since the trait is recessive in women (meaning that it is covered up by a capital X) it means his mother could have the trait in one of her chromosomes, but not the other. Unfortunately Bob got the short end of the stick and got the chromosome with color blindness, and since men only have one X chromosome, it is dominant in men, leaving Bob with color blindness.