Because you might have just done something different with the experiment and messed up someway during the test
 
        
                    
             
        
        
        
Answer:
A biological community in which association takes place between the organisms and their physical surroundings is termed as an ecosystem. It can also be defined as an association between the nonliving and living components found within the environment. A particular geographical region, which is specified for the species thriving within it is known as a biome.  
A branch of science, which deals with the natural procedures that comprise fire within an ecosystem and the ecological influences it imparts, the association between the biotic and the abiotic constituents of an ecosystem with the fire, and the role played by fire within an ecosystem is termed as a fire ecology.  
Different kinds of ecosystems like savanna, prairie, coniferous forests and chaparral have originated by the contribution of the fire, which plays an essential role in the renewal and vitality of the habitat. Different kind of plant species needs the assistance of fire to establish, to reproduce, or to germinate. In case, if the suppression of wildfire takes place, it will eventually result in the eradication of various plant species and the animals that rely upon them.  
 
        
             
        
        
        
In "The Tell-Tale Heart," what prevents the narrator from killing the old man during one of the first seven nights? The narrator says that his reason for killing the old man is that he does not like the old man's "pale blue eye, with a film over it" - he calls it a "vulture eye" and an "Evil Eye".
        
                    
             
        
        
        
<span>Glucose —- pyruvate — acetyl-CoA — carbon dioxide Glucose is oxidized during <span>respiration.
I hope this helps.
</span></span>