Explanation:
d. when the growth rate is at its highest
 
        
             
        
        
        
The largest is the Biosphere 
        
             
        
        
        
Living and nonliving things in an ecosystem interact with each other; on the other hand, plants use energy from the sun.
Explanation:
The ecosystem is an interaction circumstance between the living and non - living things which exists in an environment and has an impact on its too. The essential source of energy to this ecosystem is the solar energy coming from the sun.
But the energy from the sun could only be taken up by the plants and being used in photosynthesis to produce food and oxygen which required by other living things of the ecosystem. This essentiality is exclusive of the plants.
 
        
             
        
        
        
 Have flat bases and are often described as "puffy", "cotton-like" or "fluffy" in appearance.
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