CBSE Class 9 Answered

The mode of nutrition in which an organism is able to prepare its own food is called autotrophic mode of nutrition. Green plants follow autotrophic mode of nutrition.

Autotrophic nutrition is mainly of two types: photoautotrophic and chemoautotrophic nutrition.

Autotrophs which synthesise organic matter from inorganic substances using the energy from sunlight through photosynthesis are termed as photoautotrophs. E.g. plants, algae, cyanobacteria, phytoplanktons.

Autotrophs which synthesise organic matter from inorganic substances using chemical energy are termed as chemoautotrophs. E.g. nitrifying bacteria like Nitrosomonas, thermophilic bacteria like Thiobacillus.