Dear student,
The organisms grouped under Monera are prokaryotes. They obtain their carbon and energy from different sources, and therefore can be autotrophic, or heterotrophic.
Those which are autotrophs, produce their own food by the process of photosynthesis, or chemosynthesis.
Energy for photosynthesis is obtained from the sunlight. Other organisms obtain their energy from inorganic compounds like , ammonia, hydrogen sulfide and iron, and they use carbon dioxide as their carbon source. This is called chemosynthesis.
The other group belongs to hetrotrophs. They could be divided into :photoheterotrophs and saprophytes(or decomposers).
Other organisms are parasites which survive upon other livivng organisms.
Regards.