If a father and son are both defective in red-green colour vision, is it likely that the son inherited the trait from his father ? Comment.
Gene for colour blindness is$X-$chromosome linked. sons receive their $\mathrm{X}$ from their mother, not from their father. Male-to-male inheritances is not possible for $X$-linked traits in humans. In the given case the mother of the child must be a carrier (heterozygous) for colour blindness gene.
Mendelian disorder may be of
Sickle cell anaemia is
A woman with two genes for haemophillia and one gene for colourblindness on one of the $X$ chromosomes marries a normal man. How will the progeny 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
Assertion : Haemophilia is a recessive sex linked disease.
Reason : Haemophilia occurs due to mutation of a structural gene on chromosome $15$.