Answer:An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the system through photosynthesis and is incorporated into plant tissue
Theory because a theory is a well substantiated explanation of how a particular phenomenon works based on the set of facts which had been repeatedly confirmed through observations and experiments. A scientific theory gives reliable account of a phenomenon.
