question_answer

                If a colourblind woman marries a normal visioned man, their sons will be:                            

A)                  all normal visioned                                                        

B)                  one-half colourblind and one-half normal

C)                  three-fourths coloiirbling and one-fourth normal

D)                  all colourblind

Correct Answer: D

Solution :

                Colourblindness is a disease in which a person is unable to differentiate between red and green colour. The gene for this disease is located on the X-chromosome. So, if a colourblind woman marries a normal man, it will produce all the sons colourblind \[({{X}^{C}}Y)\]. In case of a carrier woman the probability of a colourblind and a normal son is 50 : 50.