Autotrophic organisms generally have no digestive function, so they cannot swallow other organisms (such as animals and fungi). Therefore, autotrophs use other methods to maintain life, such as photosynthesis used by plants. However, plants still need water, visible light and carbon dioxide in the process of photosynthesis, which are the basic conditions for autotrophs to survive.
As an ecological word, autotrophs are also called independent vegetative organisms, and its corresponding word is heterotrophs. Organisms that survive and reproduce by inorganic nutrition are the corresponding words of organic nutritious organisms. Organisms that assimilate carbon by using energy obtained from chemical dark reactions such as respiration or photochemical reactions are called chemoautotrophs and photoautotrophs respectively. An organism that feeds on inorganic substances and can produce organic substances for its own growth. Including most green plants and chemosynthetic bacteria, they are producers of organic matter in the ecosystem and the basis of the food chain in the ecosystem.
Autotrophic organisms can obtain nutrients and energy needed for their own life activities in the process of synthesizing organic matter from inorganic substances. Green plants, such as algae, mosses, ferns and seed plants, rely on their unique chloroplasts and use solar energy to synthesize organic substances from CO2 and water to feed themselves. Some chemically synthetic bacteria, such as nitrifying bacteria, sulfur bacteria, iron bacteria, etc. , can oxidize inorganic substances, using the energy released by oxidation to make the required nutrients.