Question

7. What is the function of the contractile vacuole in paramecium caudatum. ? Why is this an important function?

8. Are these organisms autotrophic, heterotrophic, or mixotrophic? Explain how you know.

Answer 1

Paramecium are the ciliated protozoans.These are aquatic ,actively moving organisms because of the presence of thousands of cilia.contractile vacuole plays important role in regulating osmotic pressure.We know that in osmosis,water will move from its region of higher concentration to its region of lower concentration until equilibrium is reached.same process happen when paramecium caudata are in fresh water(hypotonic).water will move from outside into the cell through the semipermeable plasma membrane by the process of osmosis.when excess amount of water are there inside the cell,contractile vacuole pump out excess of water from the cell using its star like radial canals.contractile vacuole also helps in eradication of wastes.water and wastes are expel through the plasma membrane.

contractile vacuole protects the cell by checking its osmotic pressure.If contractile vacuole stop functioning then excess amount of water inside the paramecium caudata can't expel to outside.This will results in swelling of cell.At a certain time plasma membrane couldn't bear the turgor pressure any more ,at last cell will rupture.So,Contractile vacuole plays main role in protecting the cell.

Paramecium caudta are heterotrophs like the most of the other species of its phylum.They feed on small eukaryotic cells like yeast and they also feed on bacteria.They have a cavity (gullet) where food are gather.The coordinated movement of rows of cilia causes the water laden with food to be steered in to the gullet.where food are transported to food vacuole for digestion.