Modes of nutrition

This Presentation will be helpful to students of Std 10th

1. Modes of Nutrition. Subject-Science Std-X Prepared by- E va B hinde

2. Nutrients Substances which provide the two basic requirements of organisms, namely organic raw material and energy.

3. Nutrition Process of intake of nutrients from which organisms derive energy to work. Diet/ Food :- Substance which supply nutrients to the body. Carbohydrates Proteins Fats Vitamins Water Minerals

4. Modes of Nutrition means Methods of obtaining food by organisms Two Methods Holotrophic /Autotrophic Heterotrophic

5. Autotrophic Nutrition Word ‘ auto ’ means self and ‘ trophe ’ means nutrition . So, Autotrophic means ‘ self nutrition ’. In this type of nutrition, organisms synthesis their own food, like carbohydrate , from water & carbon dioxide with help of chlorophyll in presence of sunlight . This process is known as Photosynthesis .

6. E xamples Euglena Volvox Green Plants & Bacteria A green single-celled freshwater organism A green single-celled aquatic organism

7. Carbohydrates are used for providing energy. The carbohydrates which are not used, are stored in the form of starch. Energy is derived from the food which is stored in our body in the form of Glycogen . Substance which stores carbohydrates & important in controlling sugar levels in blood

8. Steps of Photosynthesis Absorption of light energy by chlorophyll Conversion of light energy into chemical energy Reduction of carbon dioxide into carbohydrates Substances important for photosynthesis Sunlight Chlorophyll CO 2

9. Heterotrophic Nutrition Organisms cannot synthesis their own food. Energy is derived by digestion of organic substances obtained from plants and animals. After intake, food is digested into simple forms and then organisms utilize it. Examples: All Animals, Some Bacteria and Fungi

10. Types of Heterotrophic N utrition Saprophitic Depends on non-living substances Dead & decaying organic material are absorbed through body wall of the organism Ex:- Bacteria, Fungi Parasitic Depends on another living organisms (Host) Has close association with the host and obtain food from it. Host is not benefited but harmed. Ex:- Bacteria, Fungi, plants like cuscuta & animal like tapeworm . Holozoic Parts of plants or animals or whole organism is taken as food. Digested with the help of digestive enzymes into simple substance, then absorbed by body cells .

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