(a) Describe the process of nutrition in Amoeba. Draw labelled diagrams to show the various steps in the nutrition in Amoeba.
(b) What is the mode of nutrition in Amoeba known as ?
(c) What is the process of obtaining food by Amoeba called ? What does it mean ?
(a) Following are the steps involved in the nutrition in Amoeba:
(i) Ingestion: Amoeba ingests food along with a little amount of the surrounding water. It does this using its pseudopodia and forms a food vacuole.
(ii) Digestion: The food in the food vacuole is digested by the digestive enzymes that enter from the cytoplasm.
(iii) Absorption: The digested food is directly absorbed in the cytoplasm of the Amoeba cell by diffusion.
(iv) Assimilation: Some part of the digested food is used for acquiring energy for various life processes. This is done through respiration.
(v) Egestion: The undigested food is thrown out of the body through the cell membrane.
(b) An Amoeba has a holozoic mode of nutrition.
(c) The process of obtaining food by Amoeba is called phagocytosis. It means cell feeding. The mode of nutrition in amoeba is phagocytosis. it is a single-celled organism in which food is taken up through the entire surface. amoeba takes in food using the temporary finger-like extensions of the cell surface which fuse over the food particle forming a food vacuole. Inside the food, vacuole complex substances are broken down into simpler ones which then diffuse into the cytoplasm. The remaining undigested material is moved to the surface of the cell and thrown out.