Question

Filling of contractile vacuole and its swelling is called

• A. Diastole
• B. Diapause
• C. Systotle
• D. Both A and B

Answer 1

The correct option is A Diastole

• A contractile vacuole is a sub-cellular organelle found in few protozoans.
  
• It is a specialized vacuole which helps in regulating the quantity of water inside a cell.
  
• It is a part of the protective mechanism which prevents the cell from absorbing too much water and also prevents the rupturing of the cell created due to excessive internal pressure.
• It expands when water enters them and is called the diastole and it contracts when the water present in the vacuole along with wastes is expelled out of the cell and is called the systole.
• So, the correct answer is 'Diastole'.