The difference between autotrophs and heterotrophs can be narrated in the terms that autotrophs are the organisms that are capable of synthesizing their own nutrients from the substances which are available in their surroundings requiring light or chemical energy for this purpose. While heterotrophs do not have the ability to prepare their food and thus they are dependant upon other organisms either plants or animals or both for food.
Autotrophs have the ability to synthesize their own food using light or chemical energy and the substances available in the environment. On the other hand, heterotrophs depend upon the other
organisms for food because they are not capable of synthesizing their own nutrients.
Autotrophs are blessed with the green pigment, i.e. chloroplast, and with the help of it, they synthesize their food. While heterotrophs do not have chloroplast, so they are unable to prepare their food. Autotrophs are common plants and form the primary level of the food chain while heterotrophs are at the secondary or tertiary level of the food chain.
Autotrophs take carbon from other inorganic sources like CO2 while heterotrophs use other organisms as the source of carbon. Autotrophs are further divided into photoautotrophs and chemoautotrophs. Photoautotrophs synthesize their food by the process of photosynthesis, e.g. all the green plants. Chemoautotrophs synthesize their food by the process of chemosynthesis, e.g.
bacteria which are found in hot water springs respectively. While heterotrophs are further divided into photoheterotrophs and chemoheterotrophs. Photoheterotrophs consume light as an energy source, but they are unable to use carbon dioxide as a carbon source. Chemoheterotrophs are the type of heterotrophs which obtain energy by directly eating the already synthesized organic
compounds and oxidizing them, e.g. animals, fungi and bacteria etc.
Autotrophs are given the status of ‘producers’ in the food chain because they are actually the source of nutrition for the organisms occupying the next levels of the food chain. Heterotrophs are further divided into herbivores, carnivores and omnivores. Herbivores are those organisms which directly eat the producers or plants, e.g. goat, buffalo, cow etc. Carnivores are those organisms that use only meat as their food, e.g. lion and omnivores are those who eat both plants and meat as their food, e.g. man.
All the green plants, algae and some of the bacteria are autotrophs because they have the ability to prepare their own food. Conversely, all the animals, i.e. lion, goat, cow, cat, dog and man are heterotrophs because they are dependant upon the producers or plants for their nutrition. They cannot prepare their own food.
Autotrophs are able to store both the energy forms, i.e. sunlight energy and chemical energy while heterotrophs cannot store energy. Autotrophs are not able to move from one place to another while heterotrophs are capable of moving from one place to another. Heterotrophs consist of almost 95% of the living organisms while rest of the 5% are autotrophs.
Comparison chart
| Basis | Heterotrophs | Autotrophs |
| Definition | They cannot prepare their own nutrients and dependant upon other organisms for nutrition. |
They are capable of synthesizing their own nutrients using sunlight or chemical energy and an inorganic carbon source. |
| Chloroplast | They do not have chloroplast. | They contain the green pigment or chloroplast. |
| Level of the food chain |
They form the secondary or tertiary levels of the food chain. | They form the primary or producer level of the food chain. |
| Source of carbon | They use performed organic compounds from other organisms as their carbon source. |
They use inorganic compounds as their carbon source like CO2. |
| Types | They are further divided into photoheterotrophs and chemoheterotrophs. | They are further divided into photoautotrophs and chemoautotrophs. |
| A constituent of living organisms | They consist of 95% of living organisms. | They consist of 5% of living organisms. |
| Locomotion | They have the ability of locomotion. | They do not have the ability of locomotion. |
| Storage of energy | They cannot store sunlight or chemical energy. | They are able to store sunlight or chemical energy. |
| Examples | They include all the fungi and animals, e.g. lion, cow, goat, camel and man. |
They include all the green plants and some bacteria. |
What are Heterotrophs?
Heterotrophs are the organisms which do not have the ability to prepare their own nutrients rather they depend upon producers to get their nutrition. They get their food either by ingestion, e.g. animals or human beings or by ingestion, e.g. fungi. They get carbon in the form of performed compounds, i.e. carbohydrates, proteins and lipids synthesized by other organisms. Human beings eat food synthesized by plants which are broken down into the stomach and absorbed from the intestine and nutrients are sent to all the body parts where these food particles are used as
energy source. The energy thus obtained is used for useful activities like reproduction and growth.
Heterotrophs can be further divided into photoheterotrophs and chemoheterotrophs. Photoheterotrophic organisms use sunlight as a source of energy while they get their carbon from other organisms. Their example can be given as purple non-sulphur bacteria, green non-sulphur bacteria and Rhodospirillaceae. Chemoheterotrophic organisms obtain both energy and carbon from other organisms. They cannot use sunlight as their source of energy. They also cannot use CO2 as a carbon source. They totally rely upon other organisms for nourishment. For example man, fox , cow etc.
What are Autotrophs?
Autotrophs are the organisms which are capable of preparing their own nutrients via photosynthesis or chemosynthesis. Depending on the mode of synthesis of food, they are further divided into photoautotrophs and chemoautotrophs. Photoautotrophs are those organisms which have chloroplast, and they prepare glucose by using carbon dioxide and water. They include all the green plants. They use the electromagnetic energy of sunlight for this purpose. Chemoautotrophs, on the other hand, use other organic and organic chemicals as their source of energy. Nitrosomonas,
Nitrobacter, and Algae are examples of chemoautotrophs.
Key Differences between Heterotrophs and Autotrophs
- Heterotrophs are not capable of synthesizing their own nutrients while autotrophs can synthesize their own nutrients.
- Autotrophs have chloroplast while heterotrophs do not have this green pigment.
- Autotrophs form the primary or producer level of the food chain while heterotrophs form the secondary or tertiary level of the food chain.
- Autotrophs use inorganic carbon sources and sunlight as their source of carbon and energy while heterotrophs use preformed organic compounds as their carbon source.
- Autotrophs are not capable of locomotion while heterotrophs are capable of locomotion from one place to another.
- All the plants and some of the bacteria are the examples of autotrophs while all the animals and fungi are examples of heterotrophs.
Conclusion
All the living things can be broadly divided into autotrophs and heterotrophs in terms of their mode of getting nutrition. They form the different level of the food chain, so it is important to know about them. In the above article, we learnt about the differences in autotrophs and heterotrophs.