Nutrition

Nutrition

Nutrition is defined as the process of intaking of nutrients and its utilisation by an organism in various biological activity.

Modes of Nutrition

1. Autotrophic
2. Heterotrophic
Autotropic nutrition: Auto = self,  Trophic = nutrition. The literal meaning of this term is self nutrition.
Autotrophic Nutrition is a process where the organism prepare their own food from the simple inorganic materials like carbon dioxide, water and mineral salts in the presence of sunlight. All the green plants possess autotrophic mode of nutrition.
The autotrophic organisms contains green pigment known as chlorophyll. It is capable of trapping sunlight and this trapped energy is utilized by the autotrophs to prepare their food, combining carbon dioxide and water by the process of photosynthesis. This results in forming of glucose.
Heterotrophic nutrition: Heterotrophic nutrition is the mode of nutrition in which organisms depend upon another organisms to survive. All animals and non green plants are heterotrophic.
Types of heterotrophic nutrition: 
Heterotrophic mode of nutrition is divided into following two types:
1. Saprophytic nutrition
2. Parasitic nutrition
Saprophytic nutrition: In saprophytic nutrition the organisms obtain their food from dead and decaying organic matter of dead plants, dead animals and other decomposing organic matter. And the organisms which obtain their food from dead and decaying organic matter of dead plants, dead animals and other organic matter are called saprophytes.
e.g. Fungi, bread mould, some protists and many bacteria are saprophytic in nutrition.
Forest Danger Cap Colorful Fungus Fly Fungi Fall
Parasitic nutrition: 

In this type of nutrition, the organisms (called parasites) depend on the body of other living organisms (called their host) for getting their food.Many viruses, bacteria, fungi and animals have this mode of nutrition.

The organisms which depend on other living organisms (host) for food are called as parasites.
Parasites of two types:

a) Ecto parasites

b) Endo parasites

Ecto parasites

Ecto parasites are those parasites which obtain their food from their host by remaining outside the body of their host. For example, mosquitoes, ticks, lice and bed bug.

Endo parasites

Endo parasites are those parasites which obtain their food from their host by remaining inside the body of their host. For example, Ascaris, plasmodium vivax and tape worm.

                                Autotrophic Nutrition                                                                      Heterotrophic Nutrition                                                                                                          

1.In autotrophic nutrition organism prepares its food from simple substances present in the surroundings .	1.In heterotrophic nutrition organism obtains food from digesting organic compounds .
2.Autotrophs are the producers in the food chain .	2.Heterotrophs are the consumers in the food chain .
Example : Plants obtain food by autotrophic nutrition .	Example : Some plants and all animals obtain food by heterotrophic nutrition .
3.Autotrophs are fundamental to the food chains of all ecosystems in the world. They take energy from the environment in the form of sunlight or inorganic chemicals and use it to create energy-rich molecules such as carbohydrates. This mechanism is called primary production.	3.Organisms, called heterotrophs, take in autotrophs as food to carry out functions necessary for their life. Thus, heterotrophs are — all animals, almost all fungi, as well as most bacteria and protozoa — depend on autotrophs, or primary producers, for the energy and raw materials they need.
Types of Autotrophic nutrition: (i)Phototrophic (ii) Chemotrophic	Types of Heterotrophic nutrition : (i) Holozoic (ii) Saprophytic (iii)Parasitic and (iv) Symboitic Association