Given below is a highly simplified representation of the human sex chromosomes from a karyotype.

The genes $a$ and $b$ could be of

Following characters are indicate

$(i)$ presence of sickle – shaped $RBC$

$(ii)$ Blood not clot, non stop bleeding

$(iii)$ The heterozygous female transmit the disease to sons.

$(iv)$ Both heterozygous parents transmit the disease to offspring

A son of a colourblind father and normal homozygous mother marries to a daughter of normal father and heterozygous mother than their children will be

Sickle -cell anaemia has not been eliminated from the African population because it

Choose incorrect statement for haemophilia.