1. Autotrophs prepare organic food by photosynthesis.
2. It is mainly of two types – photoautotrophic and chemo autotrophic nutrition.
3. They depend on solar energy directly.
4. In this process CO2 is taken and O2 is released. E.g. Green plant and animal like Euglena.
1. Heterotroph depends on autotrphs for food.
2. It may be holozoic, saprozoic, osmotrophic, parasitic, etc.
3. They depend on solar energy indirectly.
4. In this process food is taken into body and undigested food is released outside of the body, e.g. Bacteria and all animals.