Which of the following is a genetic disease?

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?

Give scientific reasons: The product of phenylalanine catabolism excreted in the urine in phenylketonuria.

In humans,a gene located on the $X$-chromosome can be responsible for:

Given below is a pedigree showing the inheritance of Myotonic Dystrophy,an autosomal dominant disorder. The genotypes of person $1, 2$ and $3$ in this family tree are:

How many types of genotypes are observed in sickle cell anemia?