Question

Amoeba acquires its food through a process termed as
A) Exocytosis
B) Endocytosis
C) Plasmolysis
D) All of the above

Answer 1

Hint:Amoeba shows holozoic mode of nutrition. The mode of nutrition takes place in five steps- ingestion, digestion, absorption, assimilation and egestion. Ingestion is the first step where the solid food is taken inside the body of amoeba as a whole.

Complete answer:
The amoeba is an unicellular organism which mainly lives in marine or aquatic habitats. It obtains its food by a method of holozoic nutrition. The organisms in this mode of nutrition take in the solid or liquid food as a whole and digests it inside the body. The nutrition in amoeba takes place in following steps:
Ingestion- It is defined as the process of taking in the food by absorbing or by swallowing it. The amoeba consists of false feet known as ‘pseudopodia’ which helps in engulfing the food. Amoeba extends these pseudopodia and engulfs the food forming a food vacuole.

>Digestion- The process of breakdown of complex food materia to simpler forms is known as digestion. The engulfed food in the food vacuole is converted to soluble forms with the help of digestive enzymes.
>Absorption- All the digested food has to be passed on to the blood. The process of passing the digested food to the blood is known as absorption. This process is also called diffusion.
>Assimilation- It is the process where the amoeba obtains energy from the digested absorbed food material. The absorbed food materials are utilised to produce energy for various life processes.
>Egestion- All the undigested food material has to be thrown from the body. This process occurs by rupturing the cell membrane and removing the waste.

Exocytosis is the process of releasing molecules from the body of an organism. Plasmolysis refers to loss of water from the plant causing it to shrink. Endocytosis is the process by which the molecules enter the body of an organism. This is the method which is seen during nutrition in amoeba.

Hence, the correct answer is option (B).

Note:Amoeba is an unicellular organism. It shows holozoic mode of nutrition where it engulfs the whole food and digests it using various digestive enzymes. This method of engulfing the food molecule is called endocytosis or phagocytosis.