Question

What are the steps involved in nutrition of Amoeba? Explain them?

Answer 1

Hint: Amoeba is a unicellular organism which comes under the Kingdom Protista. As they possess a true nucleus they are recognized as eukaryotes and have the ability to change their shape. Some Amoebas can cause diseases in human beings.

Complete Answer:
Holozoic nutrition is the type of nutrition that takes place in Amoeba. The process of nutrition in Amoeba involves the following process;
Ingestion: In this process the food is taken inside through the mouth by swallowing or absorbing it. Phagocytosis is the process in which Amoeba encircles the food using the pseudopodia encircles and then engulfs it forming a food vacuole. The initial digestion takes place inside the mouth.
Digestion: digestion takes place with the aid of few enzymes and are used by the cells for producing energy. Here the food vacuoles are transported deeper into the cell and with the help of the enzymes, the large insoluble particles are broken down to the simplest molecules.
Absorption: In this process of absorption, the nutrients from the digested food material are absorbed into the cell’s cytoplasm by leaving behind the undigested particles. This process is called diffusion. The excess food is stored in the form of glycogen and lipids.
Assimilation: It is the process of obtaining energy from the absorbed food molecules. They are utilized for producing the energy required to carry out different life processes within the cell.
Egestion: It is the process of excretion of undigested food material and it is carried out by rupturing the cell membrane to remove the undigested food material from its body.

Notes:
The lifespan of a typical Amoeba is only two days as it undergoes binary fission but the daughter cells are the same as its parent cell so in a way Amoeba can be termed as immortal.
When living conditions are unfavourable, an Amoeba transforms itself into a protective microbial cyst. When conditions are satisfactory it can revert back to its trophozoite stage, where it can start feeding again.