The contractile vacuole is a water bubble present in the endoplasm of the amoeba. The role of the contractile vacuole is same as the role of the central vacuole in plants.
The contractile vacuole stores the water and the waste material of the cell, along with some mineral and other substance, so, they help in the maintenance of the osmolarity. In case, the walls of the contractile vacuole is damaged, the cell may burst out.
The best way to increase validity of data in an experiment is by performing the experiment numerous times and obtaining measurements and data upon each run of the experiment.
