Red green colour blindness appears due to
Excessive drinking of alcohol
Inheritance through $X$ chromosome
Over activity of adrenal
Vitamin $A$ deficiency
A woman has a haemophilic son and three normal children. Her genotype and that of her husband with respect to this gene would be
Carrier of genes of colour blindness are present in
Haemophilia is example of
Most studies on human genetics have been made through
In the given pedigree, indicate whether the shaded symbols indicate dominant or recessive allele.