Sickle-cell anaemia happens due to ...$A$... mutation in which ...$B$... of haemoglobin is affected.
Fill the correct option for $A$ and $B$
Choose incorrect statement for haemophilia.
Mr. Stevan is suffering from haemophilia and cystic fibrosis. His father is hetrozygous for cystic fibrosis. The probability of Stevan's sperm having recessive $X-$linked as well as autosomal allele is
A colour blind son will born when