Table of Contents
The only source of energy available to all living things on Earth is food. Food is necessary for organisms to obtain nutrition and energy. In living organisms, nutrition obtained from food is the primary source of energy needed to survive and perform biological functions. Nutrients are essential to the growth and effective functioning of all living things. However, there are differences in the ways that they meet this need. While some creatures use complex molecules, others feed on basic inorganic substances to achieve their nutritional needs.
This mode of nutrition is divided into two types: the autotropic mode of nutrition and the heterotropic mode of nutrition. Autotrophic nutrition is found in green plants. It is the process by which organisms, such as plants, use processes like photosynthesis to create their food. On the other hand, in the heterotrophic mode of nutrition, organisms depend on other autotrophs for food. In this article, we will learn about difference between autotrophic and heterotrophic nutrition in detail.
Autotrophic and Heterotrophic Nutrition
The organism that can prepare their food from basic materials found in their environment is called autotrophs, which have an autotropic mode of nutrition. In contrast, organisms that cannot prepare their food and are completely dependent on others are called heterotrophs and follow the heterotropic mode of nutrition.
What is Autotrophic Nutrition?
When an organism can produce its organic molecules from inorganic sources like carbon dioxide (CO2) and water (H2O), it is said to be an autotrophic mode of nutrition. The process by which food is prepared in the autotrophs is called photosynthesis. The organisms that use an autotrophic mode of nutrition are known as autotrophs.
Autotrophic nutrition examples include all types of green plants. These green plants use the pigment chlorophyll, which is found in plant cells. This pigment helps them synthesize food by absorbing solar energy. Moreover, carbohydrates are converted to fatty acids to produce lipids. Both autotrophs and heterotrophs can use carbohydrates, proteins, and lipids as energy sources during respiration.
As producers, all autotrophs occupy the primary trophic level in the food chain. Autotrophs serve as the basis of the ecosystem of the food chain. The energy provided by the autotrophs is later used up by the heterotrophic organisms.
There are two forms of autotrophic nutrition: phototrophic and chemotrophic. The organisms classified as phototrophs use solar energy to perform various cellular activities. The majority of phototrops use photosynthesis with the help of sunlight. On the other hand, the organisms known as chemotrophs get their energy from the oxidation of chemical molecules. They use the process of chemosynthesis, which does not require sunlight.
What is Heterotrophic Nutrition?
Heterotrophs are living things that are unable to make their food. They depend on the autotrophs for their food and energy requirements. Since they are consumers, heterotrops occupy the secondary or tertiary level of the food chain. They get their energy from the digestion and cellular respiration of complex organic substances, like proteins, lipids, and carbohydrates.
Heterotropic nutrients are found in humans, and all other non-green plants and animals are some examples of heterotrophs. Heterotrophs obtain their food from autotrophs in many ways. Some of them include using the oxygen prepared by autotrophs, consuming herbivore plants directly, or other herbivore animals.
The four forms of heterotrophic nourishment are holozoic, parasitic, symbiotic, and saprophytic. It is the process of nutrition that takes place inside the bodies of organisms. It has five phases, namely, ingestion, digestion, absorption, assimilation, and egestion.
Holocozoic nutrition is shown by a unicellular organism called the amoeba.
Saprophytes are organisms that consume only dead or decaying matter to fulfill their energy requirements. They are an essential component of the ecosystem because they recycle nutrients back into it and maintain the cleanliness of our surroundings.
Parasites are organisms that reside in or on other organisms and feed on the host organism. The majority of parasites are unhealthy for their hosts and can occasionally. The Cuscuta plant, tapeworms, and head lice are a few examples of parasites.
A symbiotic relationship describes a relationship where two organisms share food and shelter. In this type of relationship, both organisms are mutually beneficial. An example of a symbiotic relationship includes nitrogen-fixing bacteria and leguminous plants.
Can Plants be Heterotrophic?
Yes, some plants that cannot prepare their food; these plants are called heterotrophic plants. These plants depend on their hosts for survival. Some heterotrophic plants lack chlorophyll and thus rely on other plants for nutrition. Here are some examples of such plants.
Parasitic plants
Heterotrophic plants that are reliant on their host include parasitic plants. A parasitic plant gets all or a part of its nutrition from another plant, known as the host, without benefiting the host or harming it.
Saprophytic plants
Like bacteria and fungi, saprophytes are plants that lack chlorophyll and feed on dead materials. These kinds of plants use their enzymes to break down organic matter into simpler forms so they can take in nutrients. A few examples of saprophytic plants are mushrooms, molds, corallorhiza orchids, etc.
Insectivorous plants
A plant that feeds on insects is called an insectivorous plant. It has leaves with specific functions that attract and eat insects. Every leaf of these plants has long spines covering its edges. Due to the nectar produced by the plants, insects are drawn to the leaves of the plant. The leaf quickly closes in response to a fly touching the leaves.
Difference Between Autotrophic and Heterotrophic Nutrition
| Autotrophic | Heterotropic |
| The type of nutrition with which an organism can prepare its food. | The type of nutrition in which an organism cannot prepare its food. |
| The organisms are known as producers. | The organisms are referred to as consumers. |
| They convert light energy into chemical energy to obtain energy. | They get energy from other organisms, either directly or indirectly. |
| Both chemical and light energy can be stored by autotrophs. | Energy cannot be stored by heterotrophs. |
| The chloroplast helps in food preparation. | They are unable to prepare food because they lack chloroplasts. |
| They are called producers | They are called consumers |
| Examples include green plants and algae. | Examples include humans, tigers, buffaloes, and cows. |
FAQs on Difference Between Autotrophic and Heterotrophic Nutrition
What is the mode of nutrition in plants?
Plants mostly show the autotrophic mode of nutrition. However, there are some plants that depend on others for food since they don't have chlorophyll.
What is the mode of nutrition in blue-green algae?
Blue-green algae can exhibit both autotrophic and heterotrophic modes of nutrition
What are the different types of autotrophs?
The different types of autotrophs include photoautotrophs and chemoautotrophs. The organisms that use sunlight to make their food are known as photoautotrophs. Chemoautotrophs are organisms that use inorganic energy sources to convert carbon dioxide into energy
