An atom that gains a negative electron, it becomes a negative ion. If it loses an electron it becomes a positive ion. Some atoms lose electrons and become positive ions. Others gain electrons and become negative ions.
 
        
                    
             
        
        
        
Answer:
sea floor spreading occurs at mid ocean ridges 
 
        
                    
             
        
        
        
Pretty sure it would be the nerves attatched to the heart valve
        
                    
             
        
        
        
Answer: B. meiosis 
Explanation: Meiosis is a process where a single cell divides twice to produce four cells containing half the original amount of genetic information. These cells are our sex cells – sperm in males, eggs in females. During meiosis one cell? divides twice to form four daughter cells. 
 
        
             
        
        
        
Higher trophic level is further up the food chain. Further up you go there are less and less competitors. So the answer is true