Question

Explain the process of nutrition in amoeba.

Answer 1

Hint: Some living cells engulf or ingest other cells or food particles as a whole this process is called phagocytosis and such organisms are called phagocytes. Phagocytosis is seen in amoeba, white blood cells etc.

Complete answer:
We know that amoeba is a unicellular organism in which nutrition occurs through phagocytosis, i.e. it engulfs the particle as whole. Such a mode of nutrition is called holozoic mode of nutrition.
Let's discuss the steps involved in the process of nutrition in amoeba.
1. Ingestion- Amoeba engulfs the food particle with the help of pseudopodia (false feet). Pseudopodia encircle the food particle and engulf it forming a food vacuole.
2. Digestion- It involves the breakdown of large and complex food particles to smaller and simpler molecules. It occurs with the help of digestive enzymes.
3. Absorption-It is the process by which the nutrients from the digested food are absorbed into the cell cytoplasm.
4. Assimilation- The absorbed nutrients are utilized in the cytoplasm to produce energy, this process is called assimilation.
5. Egestion- The removal of undigested food material is called egestion. It occurs by the rupturing of a cell wall and releasing the waste.

Note:
Amoeba is a unicellular organism, devoid of any digestive system. It attains its nutrition by diffusion through its body surface with the help of pseudopodia. Digestion is carried out by digestive enzymes present in the cytoplasm.