How Many Types of Heterotrophic Nutrition

Introduction

Heterotrophic nutrition is of 3 types. It is a form of nutrition where organisms rely on autotrophs, either directly or indirectly for food. These organisms are known as heterotrophs. Heterotrophs are unable to prepare their own food. All eukaryotes are unable to produce their own food, except green plants. Food is usually obtained from other organisms. All heterotrophs, except blood and gut parasites, must convert solid food into soluble compounds that can be absorbed easily and the process is known as digestion.

The soluble products of digestion are then broken down for the release of energy (respiration). All heterotrophic organisms rely on autotrophs for nutrition. The three main types of Heterotrophic nutrition are:

• Saprophytic Nutrition

• Parasitic Nutrition

• Holozoic Nutrition

Saprophytic Nutrition

In this type of nutrition, organisms obtain their nutrition from dead and decaying matter. These types of organisms are known as saprophytes. For example Yeast.

Fungi and some kinds of bacteria are examples of saprophytes. They are responsible for the deterioration of bread and similar food products. Saprophytes produce certain types of enzymes that act on complex organic matter and break them down into constituents that they can easily consume.

The saprophytes have special types of cell membranes that are used to absorb nutrients. During the process of saprophytic nutrition, carbohydrates, proteins and lipids are broken down into less complex molecules.

Parasitic Nutrition

In this mode of nutrition, organisms live inside or outside the body of another organism in this mode. They absorb nutrients from other organisms without killing them. Such organisms are known as parasites. Ascaris or roundworms are the types of parasites that live in the human body.

Cymothoa exigua is a type of rare parasite which is also known as the tongue-eating louse as it lives in the mouth of the fish Lithognathus. It breaks off the blood supply of the fish’s tongue causing the tongue to fall off. Then the louse attaches itself to the remaining tongue and acts as the fish’s new tongue.

Ectoparasites-The parasites that live outside the host’s body and derive their energy from the living thing are known as ectoparasites. Ectoparasites include organisms like lice, bedbugs, ticks, and mosquitoes.

Endoparasites- The parasites that stay inside the host body and feed and derive their energy from it are known as endoparasites. The Ascaris, tapeworm, Plasmodium vivax, etc. are examples of endoparasites.

Holozoic Nutrition

Organisms that feed on complex matter exhibit holozoic nutrition. As a result, this matter is digested, and nutrients are absorbed. For example human beings. Holozoic nutrition is also exhibited by the amoeba by encircling the food with its pseudopodia. Amoeba then swallows up the food by the process of phagocytosis. Food vacuoles of Amoeba are high in digestive enzymes, which help to break down the food into simpler substances. This process is referred to as digestion. This digested food is then absorbed into the cytoplasm, leaving behind undigested materials. This food is required to generate energy for cell growth and development. Later the undigested food is expelled by rupturing the cell membrane.

Different Types of Holozoic Organisms

Holozoic organisms are mainly divided into three types:

Herbivores: The type of animals that depend upon plants for their food and nutrition are known as herbivores. Examples of herbivores are elephants, deer, and cows among others.

Carnivores: The animals that feed on, and consume or depend on other animals for their food are known as carnivores. Examples of carnivores are lions, tigers, and wolves, among others.

Omnivores: These are the animals that can survive on other animals as well as plants for their source of food. Some Examples of omnivores are ants, pigs, cockroaches, and raccoons among others.

Significance of Heterotrophs

• Heterotrophs are a group of organisms that provide food and energy to other organisms.

• Heterotrophs are found at different levels in the food chain such as secondary or tertiary consumers.

• Detritivores are another category of heterotrophic organisms. These types of organisms feed on the leftovers of plants and animals as well as feed on faeces to get their nutrition.

• Detritivores contribute significantly by preserving a healthy ecosystem by recycling trash.

• Saprophytes play a crucial role in preserving ecological equilibrium by reducing dead and decaying materials into less complex matter that plants can absorb and recycle.

Conclusion

Heterotrophic nutrition is a type of nutrition where organisms either directly or indirectly depend on autotrophs for food. These organisms are known as Heterotrophs. They are unable to prepare their own food. Prokaryotes are examples of heterotrophic nutrition. They usually rely on other sources of nourishment, including plant and animal debris. Heterotrophs include all animals and non-photosynthetic plants as they are incapable of preparing their own food. Humans and other organisms transform food into energy. Fungi, on the other hand, depend on the decomposition of organic material for their nutrition.