In which among the following phenomenon failure of cytokinesis after telophase stage of cell division results in an increase in a whole set of chromosomes in an organism ?

Polyploidy

The correct answer is Option (2) – Polyploidy

In the phenomenon where failure of cytokinesis after the telophase stage of cell division results in an increase in a whole set of chromosomes in an organism, it is referred to as: Polyploidy

• Aneuploidy: 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.
• Polyploidy: Failure of cytokinesis after telophase stage of cell division results in an increase in a whole set of chromosomes in an organism and, this phenomenon is known as polyploidy. This condition is often seen in plants.
• Inversion: Inversion refers to a structural rearrangement of chromosomes where a segment of the chromosome is reversed.

Therefore, in the context of an increase in a whole set of chromosomes, the correct term is polyploidy, which occurs due to a failure in the normal process of cell division and cytokinesis.