One way of detecting sex linked inheritance is

Haemophilia is more commonly seen in human males than in human females because

If a boy's father has haemophilia and his mother has one gene for haemophilia; what is the chance that the boy will inherit the disease

Which is correct for inheritance of autosome linked recessive gene?

Pick out the correct statements.

$I.$ Haemophilia is a sex-linked recessive disease

$II.$ Down's syndrome is due to aneuploidy

$III.$ Phenylketonuria is an autosomal dominant gene disorder

$IV.$ Phenylketonuria is an autosomal recessive gene disorder

$V.$ Sickle cell anaemia is an $X$-linked recessive gene disorder