Answer:
Presence of papillary muscles
Explanation:
- Papillary muscles are structural components of the ventricles. 
- They are attached to the cusps of the mitral and tricuspid valves through connective tissue strings known as the cordinae tendeneae (heart strings).
- These muscles prevent the prolaspse of these valves during ventricular systole.
-  Although they differ in number i.e. two in left and three in right ventricle, papillary muscles are present in both ventricles.
 
        
             
        
        
        
The Bering Strait separates Siberia and Alaska.
        
                    
             
        
        
        
Those would be oceans and lakes. Hope this helps and have a nice day!
        
                    
             
        
        
        
One strand show ATTCCGA so the other will show TAAGGCT !
        
             
        
        
        
The answer is B. Precipitin Test.