Shilpa's father is colourblind, as is her maternal grandfather (her mother's father). Shilpa herself has normal sight but carrier for colourblind. Shilpa and her husband, Sanjay who is also colourblind, have just had their first child, a son they have named Arjun. Answer the following questions about this small family:
(a) What is the probability that this child will be colour-blind?
(b) Three sources of the colour-blindness allele are mentioned in this family. If Arjun is colourblind from which of these three men (Shilpa's grandfather, Shilpa's father or Sanjay) did he inherit the allele?
(c) Using proper pedigree format, diagram the available information about the four generation of this family described, assuming that Arjun is colourblind.
(d) If Sanjay was not colourblind, how would this affect the prediction about Arjun?

Explanation

`50%`
(b) Shilpa.s father. (Hint: Through criss-cross pattern of inheritance).
(c) Draw a pedigree chart.
(d) It will not affect Arjun since colourblind gene from Shilpa.s father is inherited to Arjun.