Question

Similar structure(in function) to the human kidney in Amoeba is
A. Nucleus
B. Contractile vacuole
C. Plasmodesmata
D. Plasma membrane

Answer 1

Amoeba is a unicellular animal. Amoeba eats and moves with the help of extending finger-like projections of protoplasm. Its shape can be changed by extending and retracting pseudopods. Excretory products of amoeba are ammonia and carbon dioxide. Kidneys are paired organs that have a bean-shaped structure. They filter the human blood and are the excretory organ of humans.

Complete answer:
-In amoeba, excretory waste such as ammonia is collected by contractile vacuole from the intracellular fluid by both active transport and diffusion.
-The excretory organ of the amoeba is a contractile vacuole as the excretory organ kidney of the human.
-The nucleus is the main organelle of the amoeba that controls reproduction and other functions such as growth and eating.
-Plasmodesmata are the cytoplasmic bridges for intercellular communication.
-The plasma membrane surrounds the amoeba and allows the movement of some material to pass into the cell and blocks the entry of other substances.
So, from the above points it's clear that option A, C and D are incorrect.

Hence, the correct answer is option (B).

Additional information:
-Contractile vacuole maintains the amount of water inside a cell.
-It is an osmoregulatory organelle of free-living protozoa and amoeba.
-It is spherical.
-It maintains the osmotic pressure.

Note: In amoeba, the contractile vacuole acts as an excretory organ. Waste materials such as ammonia and carbon dioxide are excreted by the diffusion process by the general body surface because they are small in size. The waste products found in the cytoplasm of amoeba move to the contractile vacuole. When the contractile vacuole enlarges, the waste product moves to the periphery of the plasma membrane and bursts out finally and discharges it directly into the sea.