Question

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

Answer 1

(i) The process of obtaining nutrients through food that provides for the growth and health of the organism is known as nutrition.

(ii) nutrition on Amoeba:

a. Amoeba is a unicellular organism, which follows the holozoic mode of nutrition.

b. In amoeba, the process of obtaining food is called phagocytosis.

c. The various processes involved in nutrition are ingestion, digestion, absorption, assimilation and egestion.

(i) Ingestion is the process by which the amoeba takes in food. This is done by forming temporary finger-like projections called pseudopodia around the food particle, which then form a bag-like structure called vacuole.

ii. Digestion is the process wherein the food is broken down into simpler substances in the vacuole, with the help of digestive enzymes.

iii. Absorption is the process by which the digested food in the vacuole is absorbed into the cytoplasm by diffusion.

iv. Assimilation is the process where a part of the food that is absorbed into the cytoplasm is used to generate energy for the amoeba while rest of the food, is used for growth and development.

v. Egestion is the process wherein the undigested food is thrown out of the body from the vacuole.