In which of the following disorders is a single protein that is a part of the cascade of proteins involved in blood clotting affected?

Select the correct pair:

In the given pedigree chart,the filled symbols represent affected individuals. Identify the type of inheritance:

Pedigree analysis is very important in human beings because

Mr. Stevan is suffering from haemophilia and cystic fibrosis. His father is heterozygous for cystic fibrosis. The probability of Stevan's sperm having recessive $X$-linked as well as autosomal allele is

Sickle-cell anaemia has not been eliminated from the African population because it