Principles of Inheritance and Variations (Part-2)
Failure of segregation of chromatids during cell division cycle results in the gain or loss of a chromosome(s), called aneuploidy. For example, Down’s syndrome results in the gain of extra copy of chromosome 21. Similarly, Turner’s syndrome results due to loss of an X chromosome in human females.

Principles of Inheritance and Variations (Part-2)
What is sex determination? What do mean by the tem Chromosomal disorders? To get more details about the topic sex determination please go through the video.
To get Principles of Inheritance and Variations (Part-1) Click Here