Answer:
Consumer
Explanation:
Producer An organism that can make its own food
Consumer An organism that obtains energy by feeding on other organisms
herbivores consumers that eat only plants
carnivores consumers that eat only animals
 
        
                    
             
        
        
        
Answer:
<em>In biochemistry and pharmacology, receptors are chemical structures, composed of protein, that receive and transduce signals that may be integrated into biological systems</em>
 
        
             
        
        
        
The answer is an envelope.
A virus is an infectious agent that can replicate only inside a host cell. When it is outside the cell, it consists of genetic material coated with protein capsid. Some viruses also have an envelope which covers capsid. The function of the envelope is to identify and bind some receptor sites on the host membranes. After fusing with the cell membrane, it allows to capsid and genetic material to enter the cell and infect it.
        
                    
             
        
        
        
I think the third one is the answer