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

Consider the following human disorders: $i$. Hemophilia,$ii$. Down's syndrome,$iii$. Cystic fibrosis,$iv$. Color blindness,$v$. Night blindness. Which of these represent Mendelian disorders?

Which of the following is not a correct statement regarding Phenylketonuria?

Sickle-cell anaemia happens due to $A$ mutation in which $B$ of haemoglobin is affected. Fill the correct option for $A$ and $B$.

Which of the following is not true regarding haemophilia?

$A$ woman has a haemophilic son and three normal children. What is the genotype of the woman and her husband?