Human evolution known to be a process in which species adapt to certain conditions of life, and in the battle of life and death, they are forced to become stronger in order to survive in this world. Diseases have always been present during the evolution, acting themselves as a natural selectors - the weaker organisms get sick and die. Not just humans, but all species have to establish a great protecting mechanism in order to survive. That is how our bodies are built, to be able to withstand and survive in the conditions we live in, and that is why our immune system has to be taken care of.  
        
                    
             
        
        
        
The difference between the time of the heartbeat and the pulse makes the animal Pulse Deficit.
        
             
        
        
        
Answer:
N
Explanation:
Both carbohydrates and lipids contain Carbon, Hydrogen, and Oxygen. However, all proteins have Nitrogen as well.
 
        
             
        
        
        
Answer:
They are know as heterozygous alleles. 
Explanation:
Two IDENTICAL alleles are known as homozygous<em> </em>alleles.
I hope this helps you understand the difference, and as always, I am joyous to assist anyone at any time.