The chief advantage of encystment of an Amoeba is:

During adverse environmental periods, Amoeba survive by encystment by becoming circular, loses most of its water, and secretes a cyst membrane that serves as a protective covering. When the environment is again suitable, the envelope ruptures and the Amoeba emerges. Related Theory During unfavourable conditions, Amoeba undergo multiple fission inside the cyst to survive and reproduce under unfavourable conditions. In the multiplefission, the nucleus of the parent cell divides multiple times by amitosis (direct cell division), producing several nuclei. The cytoplasm, later on, separates, creating multiple daughter cells. When the conditions are unfavourable, Amoeba withdraws its pseudopodia and becomes almost round.