Genes of colour blindness are carried in

Colour blindness results from

Assertion : Haemophilia is a recessive sex linked disease.

Reason : Haemophilia occurs due to mutation of a structural gene on chromosome $15$.

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

If both parents are carriers for thalassemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child?

Haemophilia is