Heterotrophic Nutrition
Unicellular life processes refer to the operations of several organs and organ systems that sustain the existence of organisms. Every living thing on Earth relies on nutrition, breathing, transportation, excretion, and reproduction to sustain its survival. Living organism get their food in 2 modes ie., Autotrophic and Heterotrophic.
Autotrophic Nutrition
Primary consumers known as autotrophs are capable to grow their nourishment. To do that, they need sunlight, water, and air. Additionally, it is borrowed from Greek. Trophy means nurture, whereas auto means oneself.
In general, photosynthesis is a process used by plants with green leaves, including mosses, long trees, algae, phytoplankton, and some bacteria. Here, plants absorb energy from the sun and use it to transform soil water and atmospheric carbon dioxide into glucose, and nutrition.
S.No. |
Autotrophic |
Heterotrophic |
1 | Usually members of the plant kingdom and certain unicellular organisms | All members of the animal kingdom |
2 | These are producers who prepare their own food | These are consumers who depend on others for food |
3 | These are classified as photoautotrophs | These are classified as photoheterotrophs |
4 | The chloroplast helps in preparing food | They do not contain chloroplast, so can’t prepare food |
5 | These store light energy and chemical energy | These cannot store energy |
Heterotrophic Nutrition
Heterotrophic nutrition is a type of nutrition in which organisms rely on autotrophs for food, either directly or indirectly. They are known as heterotrophs. They are unable to prepare their own food. Except for green plants, all eukaryotes are unable to produce their own food. Food is obtained from other organisms. This type of nutrition is also referred to as heterotrophic nutrition.
All heterotrophs (with the exception of blood and gut parasites) must convert solid food into soluble compounds that can be absorbed (digestion).
The soluble products of digestion for the organism are then broken down for energy release (respiration). All heterotrophs rely on autotrophs for nutrition.
- Saprophytic Nutrition
- Parasitic Nutrition
- Holozoic Nutrition
Types of Heterotrophic Nutrition
The heterotrophic mode of nutrition can be classified based on the source of nutrition as follows:
Saprophytic Nutrition
Organisms obtain nutrients from dead and decaying organic matter in this mode of nutrition. Saprophytes are the name given to these organisms. Example: Yeast
Fungi and certain types of bacteria are examples of saprophytes. These are also to be held responsible for the deterioration of bread and other similar food products. Saprophytes produce enzymes that act on complex organic matter. It works by breaking it down into constituents that they can easily consume.
In saprophytes, the digestive process entails dissolving organic materials into less complex stuff. The organism’s cell membranes are used to absorb the remaining nutrients. During the process of saprophytic nutrition, proteins, lipids, and carbohydrates are broken down into less complex molecules.
Parasitic Nutrition
The organism lives inside or outside the body of another organism in this mode. It absorbs the other organism’s nutrients without killing it. Parasites are such organisms. Ascaris (roundworms) are parasites that live on the human body.
Cymothoa exigua is a rare parasite. It is also known as the tongue-eating louse because it lives in the mouth of the marine fish Lithognathus. It essentially breaks off the fish’s tongue’s blood supply, causing the tongue to fall off. The louse then attaches to the remaining tongue and features as the fish’s new tongue.
- Ectoparasites-These parasites live outside the host’s body and feed and get their energy from the living thing. Ectoparasites include things like bedbugs, lice, ticks, and mosquitoes.
- Endoparasites-These parasites stay inside the host organism’s body and feed and get their energy from it. The tapeworm, Ascaris, Plasmodium vivax, and other parasites are examples of endoparasites.
Holozoic Nutrition
Holozoic nutrition is exhibited by organisms that feed on a complex matter. This matter is digested, and nutrients are absorbed as a result. Example: Human beings.
Amoeba Holozoic Nutrition

Holozoic nutrition is exhibited by amoeba. The amoeba encircles the food with its pseudopodia. The food is then swallowed up by the process of phagocytosis. Amoeba food vacuoles are high in digestive enzymes, which assist in the breakdown of food into simpler substances. This is referred to as digestion. The digested food is absorbed into the cytoplasm, leaving undigested materials behind. This absorbed food is used to generate energy for cell growth and development. The undigested food is ejected from the cell by rupturing the cell membrane.
Types of Holozoic Organisms
Holozoic organisms can be classified into the following three types:
- Herbivores- They are animals that depend upon plants for their source of food and nutrition. Examples of herbivores include deer, elephants, and cows among others.
- Carnivores- They are animals that feed on, consume or depend on other animals for their source of food. Examples of carnivores include tigers, wolves, and lions, among others.
- Omnivores- They are animals that can survive on other animals or plants for their source of food. Examples of omnivores are pigs, ants, raccoons, and cockroaches, among others.
FAQs on Heterotrophic Nutrition
Question 1: What are the different types of heterotrophs?
Answer:
There are four different types of heterotrophs which include herbivores, carnivores, omnivores, and decomposers. Herbivores, carnivores, and omnivores exhibit the holozoic type of heterotrophic nutrition.
Question 2: Give an example of heterotrophic nutrition.
Answer:
Organisms that are unable to prepare their own food and must rely on other organisms for nutrition are referred to as heterotrophs, and this type of nutrition is referred to as heterotrophic nutrition. Examples: cows, tigers, and humans.
Question 3: What three major types of nutrition are heterotrophic?
Answer:
There are three types of heterotrophic nutrition: saprophytic, parasitic, and holozoic. Nutrition: Saprotrophic or Saprophytic In this type of heterotrophic feeding, food is derived from organic remains such as excreta, dead creatures, fallen leaves, broken twigs, food items, etc.
Question 4: What do you mean by heterotrophs?
Answer:
Heterotrophic means requiring complex organic nitrogen and carbon compounds (such as those found in plant or animal matter) for metabolic synthesis.
Question 5: What type of nutrition is shown in amoeba? What does your diet include?
Answer:
Amoeba shows holozoic nutrition. Its diet includes bacteria, microscopic plants like diatoms, minute algae, and microscopic animals like other protozoa, nematodes, and even dead organic matter.
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