All living organisms need energy to perform various life processes and the source of energy for all living organisms is food. It is available from different sources. There are two types of modes of nutrition Autotrophic and Heterotrophic.
What is Nutrition?
It is a process of taking in food and converting it into energy and other important nutrients that are required for life. Or we can say that nutrition is a process by which animal or plant takes in and utilizes food substances.
As we know that nutrients provide nourishment. Examples of nutrients are proteins, carbohydrates, fat, vitamins, minerals, fiber, and water. It is also necessary to have the right balance of nutrients in diet so that the risk of developing certain health conditions increases.
What is the Autotrophic mode of nutrition?
In this type of nutrition, organisms make their own food with the help of simple organic materials like carbon dioxide and water in the presence of sunlight. Green plants have an autotrophic mode of nutrition and such organisms are known as autotrophs.
Autotrophs have a green pigment known as chlorophyll which helps in trapping the sunlight energy. Autotrophs make their own food in the presence of sunlight and the process is known as photosynthesis. That is green plants synthesize their own food by the process of photosynthesis. The food produced by autotrophs is used by human beings and animals.
What is the Heterotrophic mode of nutrition?
From the simple organic material like carbon dioxide and water, animals are not able to make their own food and so are dependent on other organisms for food. This is known as the heterotrophic mode of nutrition. Therefore, organisms that depend on other organisms for food are known as heterotrophs. Example man, dog, cat, etc., and some non-green plants including yeast. Basically, heterotrophs depend on plants or other organisms for their food.
Difference between Autotrophic and Heterotrophic mode of nutrition
1. Autotrophs are members of the plant kingdom and some unicellular organisms like cyanobacteria. On the other hand, heterotrophs are all members of the animal kingdom.
2. The mode of nutrition in autotrophs is that they are producers and prepare their own food in the presence of sunlight with the process of photosynthesis. Whereas the mode of nutrition in heterotrophs is that they are consumers who are dependent on others for their food.
3. Autotrophs can be classified into photoautotrophs and chemoautotrophs. And Heterotrophs can be classified into photoheterotrophs and chemoheterotrophs.
4. In the food chain, autotrophs form the lowest trophic level whereas heterotrophs form the second or third trophic levels.
5. Autotrophs act as producers and heterotrophs as consumers.
6. In some autotrophs, solar energy can be stored whereas, in heterotrophs, solar energy storage or utilization is not possible.
7. In autotrophs, chloroplast helps in preparing food whereas heterotrophs do not have chloroplast so cannot prepare their own food.
8. Autotrophs obtain energy from inorganic sources by converting light energy into chemical energy whereas heterotrophs directly or indirectly obtain energy from other organisms.
9. Autotrophs cannot move from their place whereas heterotrophs can move from one place to another in search of food and shelter.
10. Examples of Autotrophs are green plants, algae, and few photosynthetic bacteria. Examples of heterotrophs are cows, buffaloes, tigers, humans, etc.
Therefore, the main difference between autotrophs and heterotrophs is that the former are able to make their own food with the help of photosynthesis whereas the latter cannot.