Definition of Nondisjunction

Nondisjunction is a phenomenon that happens when the chromosomes are unable to separate properly during the process of cell division. Consequently, such cells are produced which contain an imbalanced number of chromosomes. As we know that the DNA of the cell is present in the chromosome hence, it is extremely important for cellular functions.

During metaphase of meiosis I and meiosis II, the chromosomes line up in an orderly manner and then the cell divides into two daughter cells and these daughter cells contain an equal amount of genetic material. But sometimes, it happens that the chromosomes fail to separate equally and the daughter cells receive an incorrect number of chromosomes. This results in numerous cellular dysfunctionalities.