The endoplasm of Amoeba consists of three types of vacuoles viz.
Contractile Vacuole : Amoeba has one contractile vacuole which is formed near the nucleus by the fusion of water droplets. It is bounded by a thin plasma membrane and surrounded by many mitochondria. After attaining a specific size, it moves towards the periphery and on contact with plasmalemma burst suddenly to release the water outside. The contractile vacuole performs osmoregulation. The formation of contractile vacuole is called as diastole which is a gradual process and bursting of contractile vacuole is called as systole which is a sudden process. The contractile vacuole also helps in respiration and excretion.
