Introduction

Food is useful for the survival of the living beings because it serves as a rich source of carbohydrates, proteins, fats, vitamins, and minerals required for the supply of energy to carry out necessary life processes, proper growth, and development of the human body. It is also required for the repair of damaged body parts and to fight diseases. These components of food are known as nutrients.

Nutrition and modes of nutrition:

The mode of consumption of food by a living being and its utilization by the body is termed as Nutrition. There are two different modes of nutrition:

1. Autotrophic mode of nutrition:
In the autotrophic mode of nutrition, the living being produces its own food in the presence of simple substances. The organisms undergoing this mode of nutrition are termed as autotrophs (auto meaning self; trophies meaning nourishment).
Example: plants.

2. Heterotrophic mode of nutrition:
In the heterotrophic mode of nutrition, the living being consumes plants or other animals. The organisms undergoing this mode of nutrition are termed as heterotrophs (heteros meaning another; trophies meaning nourishment).
Example: human beings, animals.

Classification of Heterotrophic mode of nutrition

Herbivores:

The organisms that feed on plants are called herbivores. For example, deer, goat, sheep.

Carnivores:

The organisms that feed on other animals are called carnivores. For example, lion, tiger, fox.

Omnivores:

The organisms that feed on both plants and animals are called omnivores. For example, bear, and human beings.