Areessive allele on the x chromosome is responsible for red-green color blindness in humans. a woman with normal vision whose father is color-blind marries a color-blind male. what is the probability that a son of this couple will be color-blind? draw the punnet square.

50%

Explanation:

Let the allele for red-green color blindness be represented by c.

Normal vision woman whose father is color-blind will be

Color-blind male will be

  x  

Progeny: (See the attached image)

Out of the 2 male progeny, 1 is affected for color-blindness while the other is not affected. This gives a 50% probability that a son of the couple will be color-blind.