Autotrophic and Heterotrophic organisms


Depending on the ability to produce food and energy, plants can be autotrophic or heterotrophic plants. All autotrophic plants are self-dependent as they can generate their own energy through photosynthesis. The majority of the plants belong to autotrophic plants. Autotrophs can be further classified as photoautotrophs or chemoautotrophs. Phototrophs are those plants that use sunlight as an energy source, while chemotrophs use electron donors as a source of energy. Chemotrophs may get the energy from organic or inorganic sources. If in an autotroph, these electron donors come from inorganic chemical sources than they are called lithotrophs. Both the Photoautotrophs and lithoautotrophs utilize some portion of the ATP produced during photosynthesis to reduce NADP+ to NADPH to form organic compounds. Heterotrophs can be further subdivided into chemotrophs and photoheterotrophs.  Chemotrophs are those plants that obtain energy by the oxidation of electron donors in their environments. These are commonly found in the ocean floors where sunlight is not available for photosynthesis hence these plants adapt chemotrophic nutrition. Photoheterotrophs, on the other hand, use light for energy, thereby converting carbon dioxide into oxygen through the release of glucose. These plants use organic compounds from the environment to satisfy their carbon requirements.

Table Of Contents

1. Introduction

2. Differences between the autotrophs and heterotrophs

3. Saprotrophs

4. Heterotrophic plants 


Differences between the autotrophs and heterotrophs





Those plants that cannot prepare their own food instead they depend on other sources to obtain their food.

These plants can be producers and prepare their own food by using photosynthesis. They are capable of using sunlight, air, and water.


Most of the animals and some carnivores plants

Almost all green plants, algae, mammals, vertebrates, bacteria etc.


2 categories mainly Photoheterotroph and Chemoheterotroph.

2 categories are Photoautotroph and Chemoautotroph.

Source of energy

Heterotrophs get their energy directly or indirectly from other organisms.

Autotrophs obtain energy from inorganic sources, where they convert light energy (sunlight) into chemical energy.


Heterotrophs rely on other organisms for the food.

Autotrophs are independent to produce food and energy

Hierarchy level

Heterotrophs depend on autotrophs for food and are placed next on the food chain i.e. they are secondary or at the tertiary level.

Autotrophs are the primary producer in the food chain.

Storage of energy

Heterotrophs are not capable of storing energy.

Autotrophs are capable of storing sunlight and chemical energy.


They act as consumers.

They act as producers.


Heterotrophs can move from one place to another in search of food.

Autotrophs (plants) cannot move from one place to another.



Saprotrophs are mushroom-like structures which are grown in the rooting of a wooden plant or tree during the rainy season. They obtain nutrients from dead matter of other plants and animals hence they are called parasitic organisms. Some of the common saprotrophs are Rhizopus (bread mould), mucor (pin mould), Yeast, and Agaricus (a mushroom).


Heterotrophic plants 

Some of the plants do not have chlorophyll and they cant synthesize food by themselves. Such plants can turn into heterotrophic. Just like animals, these plants will have yellow tubular structures placed throughout the plant surrounded with the stem and branches. One of the examples is a marble, it doesn't have chlorophyll but it takes food from a host plant by climbing on it. The heterotrophic plant is parasitic in nature because it will utilize the nutrients of another plant. Rarely some plants can eat animals these are called carnivorous plants which can trap insects and digest them inside. Such plants will have leaves where the apex of the leaves forms a pouch-like structure and its pitcher automatically closed when the insect is directed towards it so that ultimately insect gets trapped as shown below. Fungi release certain sudden juices and the decaying matter and finally, it turns that into the solution then the solution is absorbed in the form of nutrients .his type of nutrition is called saprotrophic nutrition. Saprotrophs like fungi, algae can also grow on clothes wet leather and at some other non-metallic and soft materials in hot and humid weather.





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