Endosymbiosis 
that is my explanation hopefully its right
        
             
        
        
        
Food web provides a better model of an ecosystem and model of many different consumers
        
             
        
        
        
Seismometers and Seismographs 
 
        
             
        
        
        
Answer:
notochord, dorsal hollow nerve cord, pharyngeal slits, and a post-an4l tail
Explanation:
had to censor second to last word but the 4 is an a