Question

The contractile vacuole in protozoans are
A. Homologous to kidney of man
B. Analogous to kidney of man
C. Analogous to liver of man
D. Homologous to liver of man

Answer 1

Hint: Protozoans are single-celled organisms. Since these organisms have nuclear material developed by nuclear membrane they are called eukaryotic organisms. Protozoans are divided into four groups namely flagellates, Ciliates, Sarcodina and sporozoans.

Complete answer:
The contractile vacuole in protozoans are analogous to the kidney of man.
Protozoans are single celled, eukaryotic organisms. These organisms have heterotrophic mode of nutrition i.e. they developed other organisms for their food or nutritional development. These organisms acquire carbon in reduced form from their surrounding environment. Organisms belonging to the class protozoa possess flagella, cilia or pseudopodia. These are the locomotory structures that take part in movement. Some protozoan organisms are free-living solitary whereas some organisms are present in the form of colonies.

The contractile vacuoles are organelles found in the cells of protozoans. contractile vacuoles are organelles in cells of sponges and freshwater protozoans. The contractile vacuoles are bubble-like structures present in freshwater. Amoeba that swells with excess fluid that comes from cytoplasm. The membrane then pumps back ions to cytoplasm and as a result water leaves vacuole. In vertebrates, kidneys act as osmoregulatory organs that force fluid to filter through the walls of blood capillaries into tubules. This helps in the process of filtration. Thus, the function of kidney and contractile vacuole of osmoregulation or filtration is common. So, the contractile vacuole in protozoans are found to be analogous to the kidney of man.

Therefore, the correct answer is option (B) Analogous to the kidney of man.

Note:The process of removal of waste material from the body of living organisms is called excretion. The organs involved in excretion are called excretory organs. It includes a pair of kidneys, ureter, urethra and urinary bladder. Kidneys also function in filtration of blood.