Most studies on human genetics have been made through
Genetic engineering
Eugenics
Microscopic study of chromosomes
Pedigree charts
Phenylketonuria is a genetic disorder due to a defect in metabolism of the following.
Haemophilia is
Haemolytic jaundice is caused due to a dominant gene but only $10\%$ of the people actually develop the disease. A heterozygous man marries a homozygous normal woman; what proportion of the children would be expected to develop the haemolytic disease
Recessive characters are expressed
Sickle-cell anaemia happens due to ...$A$... mutation in which ...$B$... of haemoglobin is affected.
Fill the correct option for $A$ and $B$