Alkaptonuria is a disease where the urine is:

$A$ 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?

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

$A$ girl of normal vision whose father was colourblind marries a man of normal vision whose father was also colourblind. What percentage of their sons would be colourblind?

Which of the following pairs is incorrect?

Which of the following is not a genetic disorder?