An Autotroph is an organism that can produce its own food using Light, Water, Carbon dioxide, or other Chemicals. Because autotrophs produce their own food, they are sometimes called producers. They are extremely important because without them, There is no other forms of life can exist. Without plants that create sugars from carbon dioxide gas and sunlight via the process of photosynthesis, for example, no herbivorous animals could exist, and no carnivorous animals that eat herbivores could exist.
The term autotrophic is formed by the combination of two words, auto meaning self, and trophic meaning nutrition. The literal meaning of this term is self-nutrition.
Plants are the most familiar type of autotroph, but there are many different kinds of autotrophic organisms. Algae, which live in water and whose larger forms are known as seaweed, is autotrophic. Phytoplankton, tiny organisms that live in the ocean, are autotrophs. Some types of bacteria are autotrophs.
Most autotrophs use a process called photosynthesis to make their food. In photosynthesis, autotrophs use energy from the sun to convert water from the soil and carbon dioxide from the air into a nutrient called glucose. Glucose is a type of sugar. The glucose gives plants energy. Plants also use glucose to make cellulose, a substance they use to grow and build cell walls.
Some rare autotrophs produce food through a process called chemosynthesis, rather than through photosynthesis. Autotrophs that perform chemosynthesis do not use energy from the sun to produce food. Instead, they make food using energy from chemical reactions, often combining hydrogen sulfide or methane with oxygen.
Autotrophs are eaten by herbivores, organisms that consume plants. Herbivores are the second trophic level. Carnivores, creatures that eat meat, and omnivores, creatures that eat all types of organisms, are the third trophic level.
Herbivores, carnivores, and omnivores are all consumers—they consume nutrients rather than making their own. Herbivores are primary consumers. Carnivores and omnivores are secondary consumers. Ex: Plants, Algae- Green algae, Red algae and Bacteria such as cyanobacteria.