In phenylketonuria:

Hemophilia is more common in human males than in females because it is a:

$A$ normal-visioned woman, whose father is colour-blind, marries a normal-visioned man. What would be the probability of her sons and daughters being colour-blind? Explain with the help of a pedigree chart.

Which of the following diseases is known as a 'bleeder's disease',caused by the presence of an $X$-linked recessive gene?

$A$ son of a colourblind father and a normal homozygous mother marries a daughter of a normal father and a heterozygous (carrier) mother. What will be the phenotype of their children?

The 'Thala test' is performed for the confirmation of: