Answer:
zinc oxide is a pure substance
 
        
                    
             
        
        
        
4.
Myelin Sheath is an insulator on the axon
Hope that helps! :)
        
             
        
        
        
Answer:
A. the daisy is an autotroph
Explanation:
autotrophs get their food from the sun 
 
        
                    
             
        
        
        
After four divisions, the zygote becomes a morula- the stadium that consists of 16 blastomeres. By the fifth day of development the form of the blastocyst is formed through the processes of compaction, cell division, and blastulation. Later, specialized cells in the embryo are derived from the inner cell mass (ICM) of the blastocyst.