Given below is a highly simplified representation of the human sex chromosomes from a karyotype.
The genes $a$ and $b$ could be of
colour blindness and body height
attached ear lobe and Rhesus blood group
haemophilia and red-green colour blindness
phenylketonuria and haemophilia
Colour blindness results from
In the given pedigree, indicate whether the shaded symbols indicate dominant or recessive allele.
Haemophilia is more commonly seen in human males than in human females because
Sex linked disease is
In the above pedigree, assume that no outsider marrying in, carry a disease. Write the genotypes of $C$ and $D$.