Question

What is heterotrophic nutrition? Describe its type.

Answer 1

Hint: Nutrition is the study of nutrients and other substances present in the food concerning growth, reproduction, maintenance, and health.

Complete answer:
A heterotroph is an organism that is unable to synthesize its food, and therefore, has to rely on other sources, specifically plant and animal matter.
Heterotrophic nutrition is a mode of nutrition in which the organisms obtain readymade organic food from outside sources.
Common examples of heterotrophs include animals, fungi, and bacteria.
All green plants and animals are heterotrophic and depend on autotrophs for food. Ecologically, the secondary or tertiary consumers in a food chain are always heterotrophs.

Types of Heterotrophic Nutrition
Based on the source of nutrition, heterotrophic mode of nutrition can be divided as follows:
- Saprophytic Nutrition – organisms obtain food from dead and decaying organic matter. These organisms are called saprophytes.
Example: Yeast, Decomposers, etc.
- Parasite Nutrition – the organisms live inside or outside the body of another organism. It takes nutrition from the other organisms without killing it. Such organisms are called parasites and the organisms which provide food and shelter them are known as the host.
Example: Cuscuta, Roundworm, etc.
- Holozoic Nutrition – organisms feed on a complex matter. It involves the intake of a solid piece of food.
Example: Human beings.
- Symbiotic Nutrition – two organisms live in close relationships to benefit each other.
Example: Fungi and algae, bacteria and higher plants, etc.

Note: Nutrition is broadly classified into two main types – autotrophic nutrition (organism makes its food) and heterotrophic nutrition (organism depends upon others for food).