The process of intaking the food & utilization of food is called nutrition.


The different component of food that have distinct functions like providing energy, materials for body building, maintenance & regulation of metabolism are called nutrient.

For example – Proteins, Minerals, Vitamin, Carbohydrates, fats.

Type of Nutrition

Autotrophic Nutrition

It is a mode of nutrition in which organisms are able to build up their own organic food from inorganic raw materials with the help of energy. The organism performing autotrophic nutrition are called autotrophs. (Gk. autos-self, trophe-nourishment). e.g., Ferrobacillus (iron bacterium).

Heterotrophic Nutrition 

It is a mode of nutrition in which the organisms obtain readymade organic food from outside sources. The organisms that depend upon outside sources for obtaining organic nutrients are called heterotrophs. Heterotrophic nutrition is of three types – saprophytic, parasitic and holozoic.

Type of Heterotrophic Nutrition

Saprophytic or Saprotrophic Nutrition

It is a mode of heterotrophic nutrition in which food is obtained from organic remains like dead organisms, excreta, fallen leaves, broken twigs, food articles, etc. Organisms performing saprophytic nutrition are called saprophytes.

Parasitic Nutrition

It is a mode of hetrotrophic nutrition in which a living organisms flourishes by obtaining food from another living organism. The lving organisms which obtains food and shelter from another organism is called parasite. The organism which provides food and shelter to a parasite is known as host. An external plant parasite is Cuscuta (Amarbel). It is a non-green plant that sends haustroria or sucking roots into host plant for obtaining food and water.

Holozoic Nutrition 

It is a mode of heterotrophic nutrition which involves intake of solid pieces of food. Since solid food is taken in, holozoic nutrition is also called ingestive nutrition. The food may consist of another animal, plant or its parts. Depending upon the source of food, holozoic organisms are of three types – Herbivores, carnivores, omnivores.


(L.herba-plant, vorare-to eat). They are holozoic organisms which feed on plants or plant parts, e.g., Cow, Buffalo, Deer, Goat, Rabbit, Grasshopper, Elephant, Squirrel, Hippopotamus.


They are animals which feed on other animals. Carnivores are also called predators they hunt, kill and feed on their preys, e.g. Lion, Tiger, Leopard, Snake, Hawk.


(L.omnis-all, vorare-to eat). They are holozoic organisms which feed on both plant and animal materials, e.g. Cockroach, Ant, Pig, Crow, Rat, Bear, Dog, Humans.

Nutrition in Amoeba :

Protozoan protests carry out holozoic nutrition through intracellular digestion.


Some protests can ingest food particle from any point on the surface (e.g., Amoeba) while others have fixed points for the same (e.g., Paramoecium). Protozoans like Amoeba capture food with the help of temporary finger-like processes called pseudopodia. Protozoans like (Paramoecium have small hair-like processes called cilia.) Beating of cilia creates current in water  that pushes food particle through cytostome or cell mouth. The process of ingestion of solid food  particle by a cell or unicellular organism is called  phagocytosis.


As soon as Amoeba comes in contact with a food particle or prey, it throws pseudopodia all around the same. The tips of encircling pseudopodia fuse and the prey comes to lie in a vesicle or phagosome. This method of intake of food is called circumvallation. Amoeba can also ingest food by other methods like import, circumfluence and invagination.

Difference Between Autotropich and Heterotrophic Nutrition

Life Processes

Read : Nutrition in Plants

Nutrition Asked Questions

What are the different modes of nutrition in living beings?

The different modes of nutrition include:

  • Autotrophic nutrition
  • Heterotrophic nutrition

What are the different modes of heterotrophic nutrition?

The different modes of heterotrophic nutrition include:

  • Parasitic
  • Saprophytic
  • Holozoic

What is holozoic nutrition? Which organism exhibits holozoic nutrition?

Holozoic nutrition is the mode of heterotrophic nutrition that involves ingestion, digestion, absorption and assimilation of solid and liquid material. This type of nutrition is exhibited by amoeba that takes in complex substances and converts them into simpler substances.

What are mixotrophs?

Mixotrophs are organisms that use a mix of different sources of energy and carbon rather than a single trophic mode. Euglena is an autotroph as well as a heterotroph and is called a mixotroph.

Are all protists mixotrophs?

Not all protists are mixotrophs. A few protists are strict heterotrophs. While a few are both autotrophs and heterotrophs. The mixotrophic protists are called acetate flagellates.

What is the mode of nutrition in plants?

Plants exhibit autotrophic mode of nutrition because they can prepare their own food. Plants use sunlight, water and carbon dioxide to produce energy during photosynthesis.

Why is nutrition essential for a living organism?

Nutrition is very important to lead a healthy life. A balanced diet reduces the risk of diseases and improves the overall health of an organism. It provides energy to the cells to carry out the cellular activities and is, therefore, called the building block of life.

What is the mode of nutrition in blue-green algae?

Blue-green algae can be autotrophs, heterotrophs or mixotrophs.