Question

explain process of nutrition in a unicellular eukaryotic organism

Answer 1

Autotrophic as well as hetrotrophic

Answer 2

$\Large{\underline{\underline{\bf{Nutrition:-}}}}$

It is a process by which the organisms obtain and utilise the nutrients (food). These nutrients are the source of energy which come from outside the body of the individual organism. or Nutrition (the word derived from the term nutrient) is defined as the process of intake of nutrients andits utilization by an organism in various biological activities.

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$\Large{\underline{\underline{\bf{Nutrition\: In \: unicellular\: organisms:-}}}}$

Amoeba is a unicellular animal. Amoeba eats tiny (microscopic) plants and animals as food which floats in water in which it lives. The mode of nutrition inAmoeba is holozoic. The process of obtaining food by Amoeba is called phagocytosis (‘Phagocytosis’ means ‘cell feeding’).

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$\Large{\underline{\underline{\bf{Process:-}}}}$

The various steps involved in the nutrition of Amoeba are: ingestion, digestion, absorption, assimilation and egestion.

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★${\bold{\underline{\underline{Ingestion:-}}}}$

Amoeba has no mouth or a fixed place for the ingestion of food (intake of food). Amoeba ingests food by using its pseudopodia. When a food particle comes near Amoeba, the Amoeba ingests this food particle by forming pseudopodia around it.

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★${\bold{\underline{\underline{Digestion:-}}}}$

In Amoeba, food is digested in the food vacuole by digestive enzymes. The enzymes from surrounding cytoplasm enter into the food vacuole and break down the food into small and soluble molecules by chemical reactions.

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★${\bold{\underline{\underline{Absorption:-}}}}$

The digested food present in the food vacuole of Amoeba is absorbed directly into the cytoplasm of Amoeba cell by diffusion. Since Amoeba consists of only one small cell, it does not require blood system to carry the digested food.

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★${\bold{\underline{\underline{Assimilation:-}}}}$

A part of food absorbed in Amoeba cell is used to obtain energy through respiration. The remaining part of absorbed food is used to make the part of Amoeba cell which lead to the growth of Amoeba.

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★${\bold{\underline{\underline{Egestion:-}}}}$

Amoeba has no fixed place (like anus) for removing the undigested part of food. When a considerable amount of undigested food collects inside food vacuole in Amoeba, then it comes to the cell surface, fuses with plasma membrane and suddenly ruptures at any place, and the undigested food is thrown out of the body of Amoeba.

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$\Large{\underline{\underline{\bf{Thanks}}}}$