Define autotrophic nutrition.

Hint:- It is a type of nutrition in which an organism prepares its own food from inorganic materials like water, mineral salts and carbon dioxide in the presence of sunlight. All green plants prepares their food through autotropic mode of nutrition. Plants possessing autotrophic nutrition are known as autotrophs. For e.g. blue-green algae and bacteria.

Complete Answer:-The term ‘autotrophic’ is formed by the combination of two words, auto and trophic where auto means ‘self’ and trophic means ‘nutrition’. As clear by its name, autotrophs means self-nutrition, it is a mode of nutrition where organisms prepare their food by themselves. The autotrophs contain a green coloured pigment called chlorophyll. Chlorophyll helps in trapping energy from the sun. All green prepare their own food by using solar energy, water and carbon dioxide by the process of photosynthesis. It results in the formation of glucose. Green plants synthesize glucose into cellulose and starch with the help of carbon dioxide and water in the presence of sunlight. The synthesised glucose is then stored in different parts of the plant for using purposes. Plants prepare proteins from nitrogen which could be obtained from soil. All these food components act as a source of energy for other heterotrophic plants and animals.

Note:- In autotrophic mode of nutrition different parts of the plant play different roles to complete the process. Leaves are considered as food factories of the plant. Stomata is present in the lower epidermis of the leaf which uses carbon dioxide from the atmosphere. Root absorbs minerals and water from soil and transport them to other parts of the plant.