Heterotrophs And Autotrophs Study Guide

Autotrophs are creatures that create their food through photosynthesis, whereas heterotrophs cannot prepare their food and must rely on autotrophs for sustenance.

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According to their energy processes, organisms are classified as autotrophs or heterotrophs. Autotrophs are creatures that can synthesize energy-containing organic compounds from inorganic raw materials utilizing simple energy sources such as sunlight. Plants are the best example of autotrophs since they use photosynthesis. All other species must consume sustenance in lipids, carbs, and proteins derived from other organisms. Heterotrophs are creatures that feed on other species.

What are heterotrophs?

In a food chain, a heterotroph is a creature that consumes other species. A heterotroph is an organism that obtains energy and nutrients through the consumption of other plants or animals. The name is derived from the Greek terms hetero, which means "other," and trophy, which means "nutrition."

heterotroph-food-chain 0066f46bde Source

Heterotrophs live on the second and third tiers of a food chain, which is a series of species that offer energy and nutrients to other organisms. Each food chain is divided into three trophic levels that define an organism's position in an ecosystem. Autotrophs, such as plants and algae, occupy the first trophic level. The second level is occupied by herbivores (organisms that devour plants). The third level is occupied by carnivores (organisms that consume meat) and omnivores (organisms that eat both plants and meat). Primary consumers (herbivores) and secondary consumers (carnivores and omnivores) are both heterotrophs, whereas primary producers are autotrophs.

A detritivore is a sort of heterotrophic consumer. These organisms gain sustenance by feeding on plant and animal remnants as well as fecal waste. By recycling garbage, detritivores play a crucial part in maintaining a healthy ecology. Fungi, worms, and insects are examples of detritivores.

Heterotrophs are divided into two types: photoheterotrophs and chemoheterotrophs. Photoheterotrophs are creatures that obtain their energy from light but must still consume carbon from other species since they cannot use carbon dioxide from the atmosphere. Chemoheterotrophs, on the other hand, obtain both energy and carbon from other species.

Photosynthesis benefits heterotrophs in a number of ways. They rely on producing oxygen, which is created as a by-product of photosynthesis. Furthermore, photosynthesis supports the autotrophs on which heterotrophs rely for survival. While meat-eating carnivores do not directly rely on photosynthetic plants for survival, they rely on other animals that eat photosynthetic plants for sustenance.

What is an autotroph?

An autotroph is a living entity that can generate sustenance from light, water, carbon dioxide, or other molecules. Autotrophs are also referred to as producers since they make their nourishment.

An autotroph is a living entity that can generate sustenance from light, water, carbon dioxide, or other molecules. Autotrophs are also referred to as producers since they make their nourishment.

photo-synthesis Source

Plants are the most well-known autotrophs, although there are many more types of autotrophic creatures. Examples include autotrophic algae that live in water and are known as seaweed in their bigger forms, phytoplankton, which are microscopic creatures that live in the water, and autotrophic bacteria.

Most autotrophs produce their food through a process known as photosynthesis. Autotrophs use the sun's energy to transform water from the soil and carbon dioxide from the air into glucose, a nutrient. Glucose is an example of sugar. Glucose provides energy to plants. Plants also use glucose to produce cellulose, which they require to grow and construct cell walls.

Through photosynthesis, all plants with green leaves synthesize or make their nourishment from the smallest mosses to the tallest fir trees. Photosynthesis is also carried out by algae, phytoplankton, and certain bacteria.

However, certain uncommon autotrophs make food by a process known as chemosynthesis. Chemosynthetic autotrophs do not require solar energy to create food. Instead, they generate energy by chemical processes, frequently mixing hydrogen sulfide or methane with oxygen.


  • The two nutritional categories of organisms are autotrophs and heterotrophs.
  • Autotrophs are creatures capable of preparing their nourishment. On the other hand, heterotrophs rely on autotrophs and other species for sustenance.
  • Green plants and algae contain chlorophyll, which aids in creating food with the help of sunshine.
  • Heterotrophs include herbivores (plant-eaters), carnivores (meat-eaters), omnivores (organisms that eat both plants and animals), and decomposers (organisms that eat dead and decaying stuff).
  • Autotrophs are primary producers at the top of the food chain.
  • Heterotrophs are consumers that occupy the secondary and tertiary levels.
  • Both are necessary for the ecosystem's energy flow to be maintained.
  • Autotrophs and heterotrophs and forms of feeding play equal roles in sustaining the ecosystem's food chain.


1. What is the difference between heterotrophs and autotrophs?

Sl.No Autotrophs Heterotrophs
1 Some organisms, such as plants, make their food from simple substances. They are called autotrophs, and the mode of nutrition is known as autotrophic nutrition. Organisms that depend on plants or autotrophs for food are called heterotrophs, and the mode of nutrition is known as heterotrophic nutrition.
2 Autotrophs are called producers as they make food required by all other organisms. Heterotrophs are called consumers as they consume food prepared by autotrophs.
3 In a food chain, autotrophs make up the first trophic level Heterotrophs form the next trophic levels after plants in the food chain.
4 Plants, algae, and some bacteria are autotrophs. Most animals, fungi, and some bacteria are heterotrophs.

2. What are the autotrophic and heterotrophic components of an ecosystem?

The creatures that are capable of making their own food from basic ingredients found in their environment are classified as autotrophic. The creatures that are fully reliant on others for nourishment and get their sustenance from the plants and animals around them are classified as heterotrophic.

3. What are the 5 examples of autotrophs?

Algae, Cyanobacteria, a Maize plant, Grass, Wheat, Seaweed.

4. Give examples of heterotrophs.

Dogs, birds, fish, and humans are all examples of heterotrophs.

5. What is a heterotrophic plant?

Some plants cannot produce their food and must obtain nutrition from outside sources—these plants are heterotrophic.

6. Are fungi heterotrophs?

All fungi are heterotrophic, which means they get the energy they need to live from other organisms.

7. Give examples of autotrophs.

Examples of autotrophs include plants, algae, plankton, and bacteria.

8. Are fungi autotrophic?

Fungi are not autotrophs, and they have no chloroplasts. They can only use the energy stored in organic compounds.

9. What are the types of heterotrophs?

There are four different types of heterotrophs: herbivores, carnivores, omnivores, and decomposers.

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  1. Autotrophs and Heterotrophs. https://flexbooks.ck12.org/cbook/ck-12-biology-flexbook-2.0/section/2.17/primary/lesson/autotrophs-and-heterotrophs-bio/ . Accessed on 2 Dec 2021
  2. Heterotrophs. https://www.nationalgeographic.org/encyclopedia/heterotrophs/ . Accessed on 2 Dec 2021
  3. Autotroph vs. Heterotroph. https://www.diffen.com/difference/Autotroph_vs_Heterotroph. Accessed on 2 Dec 2021
  4. Autotrophs and Heterotrophs https://bio.libretexts.org/Bookshelves/. Accessed on 2 Dec 2021