Haemophilia,a $X$-linked recessive disease,is caused due to the deficiency of:

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

Identify the genotype of the first generation $(I)$ for an autosomal recessive disorder based on the provided pedigree chart.

Assertion : Persons suffering from haemophilia fail to produce blood clotting factor $VIII$.
Reason : Prothrombin producing platelets in such persons are found in very low concentration.

$A$ haemophilic female marries a normal male. What will be the theoretical ratio of their offspring regarding haemophilia?

In Huntington's disease,the unaffected persons are homozygous for normal allele $h$. The following pedigree is erroneous because: