The arrangement are SA node, internal pathways, AV node, AV
bundle, Bundle branches and Purkinje fibers. The anatomy of the intrinsic
conduction system causes contraction of the ventricles to activate at the apex
and move superiorly so blood is forced upward, toward the semilunar valves. 
 
        
                    
             
        
        
        
A. Most recent period of the Cenozoic era. 
        
                    
             
        
        
        
Because everything scientists do or see is put out where the whole world can see. But if they don’t do it accurately then they get proved wrong or even lose their job. And the more accurate an answer is the more opportunity they have to venture and see more Han what they already know.
        
             
        
        
        
Answer Internal and external environmental factors, like gender and temperature, influence gene expression. ... Similarly, drugs, chemicals, temperature, and light are among the external environmental factors that can determine which genes are turned on and off, thereby influencing the way an organism develops and functions.
Explanation: