Question

Both male and female have normal vision though their fathers were colour blind mothers did not have any gene for colour blindness. The probability of their daughter becoming colour blind is ______. 

Options

• 0%

• 25%

• 50%

• 75%

Answer 1

Both male and female have normal vision though their fathers were colour blind mothers did not have any gene for colour blindness. The probability of their daughter becoming colour blind is 0%.

Explanation:

  Color blindness is a recessive X-linked disease. Because their fathers were colorblind, the colorblind gene would be handed down to the female (carrier female), while the male would be normal.

Because their daughter would have at least one normal X gene from the father, the chances of her being colorblind would be nil.