The myelin sheath covers most of the axon. It is important because it helps to protect the axon and speed up the neuron firing process by decreasing the amount of time in the axon.
        
             
        
        
        
<span>1.) What is the most important source of energy that our body craves more than any other? 
Glucose is a type of sugar you would find in healthy fruits and vegetables. The body needs this to be active and full of energy. It starts as glucose, then gets turned into ATP.
2.) What are the organelles in each cell that burn this energy? 
Mitochondria, and cytoplasm.</span>
        
                    
             
        
        
        
I would go for D or A! :)
        
             
        
        
        
<span>(According to Reference)
 
Whereas an onion epidermal cell has a cell wall, a human cheek cell does not. Instead, a semi-permeable membrane surrounds the cytoplasm of the cheek cell. While there are chloroplasts present in onion cells, they are absent in cheek cells.  </span>
        
             
        
        
        
Fossils are physical evidence of preexisting organisms, either plant or animal. ... Fossils of any kind are useful in "reading the rock record," meaning they help us decipher the history of the earth. They can help us determine the geologic age and environment (the paleoenvironment) in which they were deposited.