How do genetic disorders arise? Explain by giving suitable examples.

(N/A) Every feature in an organism is controlled by one or more genes located on the $DNA$ present in the chromosomes. $DNA$ is the carrier of genetic information and is typically transmitted from one generation to the next without any change.
However,alterations or changes in the genetic material can occur,which are referred to as mutations. $A$ number of disorders in human beings are associated with the inheritance of these altered genes or chromosomes.
Genetic disorders are broadly classified into two categories:
$1$. Mendelian Disorders: These are primarily determined by alteration or mutation in a single gene. Examples include Haemophilia,Cystic fibrosis,Colour blindness,Sickle cell anaemia,Thalassemia,and Phenylketonuria.
$2$. Chromosomal Disorders: These are caused by an excess,absence,or abnormal arrangement of one or more chromosomes. Examples include Down's syndrome,Turner's syndrome,and Klinefelter's syndrome.