Matt is colour blind, yet both of his parents and his sibling have normal colour vision.One of Matt's grandparents is also colour blind.Which of Matt's grandparents is most likely to be colour blind?

Question

Quizplus · Accepted Answer

Color blindness is often inherited in an X-linked recessive manner, meaning it is passed down on the X chromosome. Since Matt is male (XY), he must have inherited his Y chromosome from his father and his X chromosome from his mother. If his mother and father have normal color vision but Matt does not, his mother is likely a carrier of the color blindness gene. She must have received a colorblindness allele from one of her parents. Since her father (Matt's maternal grandfather) would have shown color blindness if he had a defective X chromosome (as males have only one X chromosome), it is more likely that the color blindness was passed down from a carrier mother (Matt's maternal grandmother) to Matt's mother, and then to Matt. However, the question states that one of Matt's grandparents is color blind, not a carrier, which means the initial explanation misinterpreted the question's conditions. Given this, the correct answer should be reconsidered based on the direct inheritance of color blindness, not carrier status.

Matt Is Colour Blind, Yet Both of His Parents and His