Question

Kidney of vertebrates resembles with contractile vacuole of protozoans in

• A. Expelling out glucose
• B. Expelling out urea and uric acid
• C. Expelling out excess of water
• D. Expelling out salts

Answer 1

Answer: (C)

Expelling out excess of water

Contractile vacuoles are organelles in the cells of sponges and freshwater protozoans. In the freshwater Amoeba proteus, for example, the bubble-like contractile vacuole swells with excess fluid from the cytoplasm. Its membrane then pumps valuable ions back into the cytoplasm, leaving mainly water in the vacuole. Contractile proteins surrounding the vacuole then abruptly compress it, squirting the water out of the cell through a pore in the cell membrane. This organelle resembles the kidney by expelling out excess water.

So, the correct answer is option C.