Question

Amoeba has an irregular shape.
(a)True
(b)False

Answer 1

Hint: Amoeba is a protozoan that belongs to the Kingdom Protista as it is a unicellular eukaryotic organism. Any cell which shows the amoeba-like movement is also called amoeboid cells and such ameboid cells are found in fungi, algae, and animals.

Complete Answer:
The best known amoeboid protist is Chaos carolinense and Amoeba proteus and thus are most widely cultivated and used for studies inside classrooms and laboratories. There are also some harmful amoeboid protists like the intestinal parasite known as Entamoeba histolytica that causes amoebic dysentery in humans. The characteristic of amoeba is the presence of false feet known as pseudopodia which are formed by the bulging out of cytoplasm by the coordinated movement of actin microfilaments. Pseudopodia help in motility and also ingestion of food. But due to the continuously bulging out cytoplasm, pseudopodia results in the irregular shape of the amoeba.

Additional information:
Let us learn about protozoans in detail. Protozoans are mainly heterotrophic organisms that live as predators or parasites on other organisms. They are said to be primitive relatives i.e. ancestors of animals. Four major groups of protozoans are present and they are as follows:
Amoeboid protozoans: These are the organisms that live in freshwater, seawater, or even moist soil. They move and capture their prey with the help of pseudopodia (false feet). Examples include Amoeba, Entamoeba, etc.
Flagellated protozoans: These organisms possess flagella for movement. The parasitic members of this group like Trypanosoma cause sleeping sickness.
Ciliated protozoans: These organisms possess thousands of cilia on their body for movement and ingestion of food. Examples include Paramoecium.
Sporozoans: The characteristic of these organisms is the presence of an infectious spore-like stage in their life cycle. Examples include Plasmodium which is responsible for causing malaria.

So, the correct option is ‘True’.

Note:
-Amoeba has contractile vacuoles for osmoregulation and excretion. Without the presence of these contractile vacuoles, amoeba’s cell would fill up with water and burst.
-The process by which food is ingested is known as phagocytosis and by which liquid is ingested is known as pinocytosis.
-The food engulfed inside the cell is known as the food vacuole.