Difference Between Autotrophs and Heterotrophs

The most essential aspect of living is food. No living species can exist without consuming food. This food is derived and eaten by living species in 2 different modes. We are about to look at these 2 modes of nutrition that living things obtain namely autotrophs and heterotrophs. Along with their definitions, we will also get a quick understanding of their characteristics and difference between autotrophs and heterotrophs with examples. 

Difference Between Autotrophs and Heterotrophs

The key difference between autotrophic and heterotrophic nutrition in their source of intake. Autotrophs can prepare their food on their own. But heterotrophs depend on other surrounding organisms to get their required food. It is no wonder to consider autotrophs as Producers and heterotrophs as Consumers. Henceforth, heterotrophs take the position of secondary or tertiary levels, while autotrophs are present at the primary level in the food chain.  

One more contrasting feature between autotrophs and heterotrophs lies in their ability to store natural elements. Heterotrophs cannot store their energy as they spend enough in their routine activities, even while searching for food. But autotrophs are capable of storing both energy and light. 

Green plants and algae fall under the category of autotrophs as they will prepare their food by themselves using sunlight, chlorophyll by the means of the chloroplast and photosynthesis (convert chemical energy into inorganic substances). Animals such as tigers, cows, etc. cannot make their foods and hence need other species to get their nutrition (mostly by killing and also by consuming plants like a herbivore). As an added-value, animals, i.e. heterotrophs can move from 1 place to another in their search for food. But autotrophs remain in 1 stable place. 

Autotrophs and Heterotrophs

The key difference in an autotroph vs heterotroph is in their capability to get their main source of living - food. All plants are autotrophs and many animals are heterotrophs, classifying them in the way they make or get their food daily.

Autotrophs 

As we now know, autotrophs are species that are independent when it comes to food aspects. They prepare their own food with the help of water and carbon dioxide (CO2). The term ‘autotroph’ was coined by Albert Bernhard Frank. Furthermore, autotrophs can also be divided as chemoautotrophs and photoautotrophs. Since the majority of the autotrophic mode of nutrition is from plants, they also possess the characteristic of converting carbohydrates either as fatty acids to get lipids or change it into sugars such as cellulose, sucrose, starch, etc. 

Heterotrophs

From our previous understanding, heterotrophs are living organisms that cannot make food on their own and rely on other fellow species. Meaning, heterotrophs depend on autotrophs while autotrophs remain independent in getting their nutrition. The heterotrophic mode of nutrition is continually surviving based on the availability of external food sources. Similar to autotrophs, heterotrophs are also subdivided into 2 namely photoautotrophs and chemoheterotrophs. Animals, birds, non-green plants and even human beings are the best examples for heterotrophs. 

Flow Chart of Autotrophs and Heterotrophs

[Image will be Uploaded Soon]

Autotrophs and Heterotrophs Key Points

  • The prime difference between autotrophs and heterotrophs lies in their source of getting nutrition (food).

  • In the comparison of their level of importance to the ecosystem, an autotroph vs heterotroph both are equally beneficial to the natural flow of energy.

  • Autotrophs prepare their food on their own whereas heterotrophs depend on other species or autotrophs to get their nutrition. 

  • Green plants are the classic example to autotrophs as they make their food and convert chemical energy into oxygen and other inorganic substances using chlorophyll, added by the process of photosynthesis.

  • Heterotrophs get their food either by killing other animals (carnivore), feed themselves from both plants and animals (omnivore) or consume only plants (herbivore).

FAQ (Frequently Asked Questions)

1. What are Autotrophs and Heterotrophs?

Autotrophs are organisms (green plants) that can make their own food. Heterotrophs are organisms (animals and human beings) that depend on other species to get their food. 

2. What is a Heterotroph and List out its Types?

A heterotroph is called a secondary/tertiary consumer as it depends on other animals to get its food. Heterotrophs are majorly classified into several categories. To name a few, they are Scavengers, Carnivores, Decomposers, Herbivores, Detritivores and Omnivores.

3. Is there any Organism that is Both an Autotroph and Heterotroph?

Yes. Cyanobacteria is an organism that has the characteristics and functions of both a heterotroph vs autotroph (photoautotrophic behaviour).

4. Differentiate Between Autotrophs and Heterotrophs?

The main difference between heterotrophs and autotrophs lies in their ability to prepare their food or not. Source of food for autotrophs is independent as they make their food while heterotrophs depend on other living creatures due to its inability to prepare its own food.

5. Are all Green Plants Autotrophs?

No. Some green plants such as Cytinus, Rafflesia, Orobanche, Pither, will consume its prey (food) by catching other insects, creating traps and tangling animals into their leaves or buds.