There are more than simply 4 biological compounds in the human body. I suppose to categorise, the question is hinting towards the molecules like Carbohydrates ( Poly and mono saccharides ) Proteins ( Polypeptides Made of amino acids) and Fats. There is also water, but I'm hesitant to class that as a biological compound, as it's not organic. 
        
             
        
        
        
Answer:
The producers play main role in the food chain and food web as well. These organism make food by the help of the process known as photosynthesis.
Only producers have the ability to make food by trapping sunlight. All the living source needs energy to survive.
The source of food is producers so living things cannot survive without food. So there producers are considered as the main component of food chains and food web.
hence, they play a very vital role in the environment.
 
        
                    
             
        
        
        
A imprint like a foot print in a rock or on concrete when it is fresh!
HOPE THIS HELPS!!!
:)
        
             
        
        
        
Eukaryotic cells contain membrane-bound organelles, including a nucleus. Eukaryotes can be single-celled or multi-celled, such as you, me, plants, fungi, and insects. Bacteria are an example of prokaryotes. Prokaryotic cells do not contain a nucleus or any other membrane-bound organelle.