Haemophillic man marries a normal woman. Their offsprings will be

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

A colourblind man has a colourblind sister but a normal brother than phenotype of its parents is

Most studies on human genetics have been made through

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

$A$ : Sickel cell anaemia occurs due to the point mutation.
$R$ : $mRNA$ produced from $Hb(s)$ gene has $GAG$ instead of $GUG$.