Question

What is nutrition? What is the mode of nutrition in amoeba known as? Draw a diagram and explain it.

Answer 1

Hint: Nutrition is a critical basis of the health and development of an organism. Different organisms have different ways of obtaining nutrition. Amoeba engulfs the entire food particle inside the cell using pseudopodia.

Complete answer:
Nutrition is a process by which an organism takes up food and utilizes it to get energy, for growth, repair, maintenance, and excrete the waste from the body.
The mode of nutrition in amoeba is a holozoic type of nutrition.
Amoeba doesn’t have any specialized organs for nutrition. Its entire process in amoeba is carried out through a false project of its body surface called pseudopodia.
Amoeba feeds through the process of phagocytosis where the entire organism is engulfed.

The process involved in the mode of nutrition in amoeba involves the following stages:
- Ingestion
- Digestion
- Absorption
- Assimilation
- Egestion
Ingestion: Ingestion is the process of taking in the food either by swallowing or absorbing. Amoeba pushes out pseudopodia to encircle the food and engulfs it forming a food vacuole. This process is known as phagocytosis.
Digestion: It is the process of breaking down the large insoluble molecules or food particles in the small soluble molecule. In amoeba, the food vacuole is pushed deep inside the cell, where the digestive enzymes break the large food particle into smaller and simplest molecules.
Absorption: The nutrients of digested food material are absorbed by the cell’s cytoplasm through the process of diffusion. The excess food is stored in the form of glycogen and lipids. The undigested particles are left behind and are not absorbed.
Assimilation: The absorbed food molecule in amoeba is utilized for producing the energy required to carry out the different life processes inside the cell.
Egestion: - It is the process of excreting or getting rid of unwanted food molecules that were not absorbed by the cell. The cell membrane in the amoeba is ruptured and the waste is thrown out of the body

Note: Holozoic type of nutrition is a type of heterotrophic nutrition where the organism can’t produce energy on its own.
In the parasitic mode of nutrition, the organism derives food from the other organism without killing it. In the saprophytic mode of nutrition, the organism derives food from decayed organic matter of animals, plants, etc.
In holozoic mode, the organism takes up the complex food material and converts it into simpler food material through various processes.