Hairs are mostly fibrous proteins and are composed of keratin, and also the main constituent of skin, nails, wool, woof, feathers etc.
 Keratin is the essential fibrous protein which has a structural and protective functions in the epithelium.
 
        
             
        
        
        
Answer: Aristotle's and Linnaeus's classification systems both divided all life into two groups: plant and animal.
 
        
                    
             
        
        
        
Answer:
Light, minerals, and things from the periodic table!!
Explanation:
 
        
             
        
        
        
Lymphoid organs in the immune system, includes the bone marrow
        
             
        
        
        
the cell goes into osmosis and goes into hypnotic solution