1. Tardigrade
  2. Question
  3. Biology
  4. Mahesh (who is colourblind) and Soni (who is not colourblind) have a daughter Alia. Rishi (who is not colourblind) and Neetu (who is a carrier) have a son Ranbeer. Alia and Ranbeer get married. What is the probability that their daughter will be colourblind?

Q. Mahesh (who is colourblind) and Soni (who is not colourblind) have a daughter Alia. Rishi (who is not colourblind) and Neetu (who is a carrier) have a son Ranbeer. Alia and Ranbeer get married. What is the probability that their daughter will be colourblind?

 1508  220 NTA AbhyasNTA Abhyas 2020Principles of Inheritance and Variation Report Error

Solution:

The genotype of Alia will be XXc since she receives only one Xc chromosome (colourblindness chromosome) from her father. Ranbeer may be XY or XcY (since his mother is a carrier).
So we consider two possibilities:
1 . Alia XXc and Ranbeer XY. In this, the daughters could be XX (not colourblind) or XXc (not colourblind)
2 . Alia XXc and Ranbeer XcY. In this, the daughters could be XXc (not colourblind) or XcXc (colourblind)
Thus there is only 1 in 4 chance that their daughter will be colourblind.