In pedigree analysis,the symbol given for sex unspecified is

Which of the following is a genetic disorder?

Which of the following diseases in humans belongs to the same category as hemophilia?

All sons of a couple are colourblind because

In the given pedigree,indicate whether the shaded symbols indicate a dominant or recessive allele.

Both husband and wife have normal vision,though their fathers were colourblind and mothers did not have any gene for colour blindness. The probability of their daughter becoming colourblind is