In pedigree analysis,the square,blackened,and horizontal lines represent:

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.

Identify the genetic disorders based on the following characteristics:
$(i)$ Presence of sickle-shaped $RBC$.
$(ii)$ Blood does not clot,leading to non-stop bleeding.
$(iii)$ The heterozygous female transmits the disease to sons.
$(iv)$ Both heterozygous parents transmit the disease to offspring.

Quantitative defect of hemoglobin $- P$
Qualitative defect of hemoglobin $- Q$
Select the correct option for $P$ and $Q$.
$\quad \quad P\quad \quad \quad Q$

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

Recessive characters are expressed: