Arthropods were the first animals to successfully invade land from the sea
        
             
        
        
        
Science is the study and learning mechanism of the world and how everything is created as well as used today and billion of years ago
 
        
                    
             
        
        
        
Answer:
I think it's c (if y is chloroplasts) 
 
        
             
        
        
        
Answer:
The respiratory centers that control your rate of breathing are in the brainstem or medulla. The nerve cells that live within these centers automatically send signals to the diaphragm and intercostal muscles to contract and relax at regular intervals.
 
        
             
        
        
        
<span>A(n)PRIMITIVE CHARACTER  is one present in the common ancestor and all members of the group
Primitive character is also known as ancestral character in phylogenetics. It is defined as a characteristic that  has undergone little change since time immemorial and is inherited from a common ancestor of a clad.
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