Keratin is an intracellular fibrous protein that gives hair, nails, and skin their hardness, strength, and water-resistant properties. The keratinocytes in the stratum corneum are dead and regularly slough away, being replaced by cells from the deeper layers 
Hope this helped!
Good luck :p
~Emmy <3
 
        
             
        
        
        
Answer:
Brief description of the Orginal experiment state what was done
Explanation:
What did you change?
How did the changes help answer the question
 
        
             
        
        
        
<span>False. E.coli is generally about 2 micrometers in size compared to white blood cells which are around 13 micrometers in size. Also, white blood cells have a characteristic segmented nucleus with two to five lobes joined by fine strands of chromatin.</span>
        
             
        
        
        
Violet Light waves Is the answer fam
        
             
        
        
        
 In physical science there are two types of "isolated systems"
1. Being a Physical System in which it is so far removed from other systems that it does not react with any of them.
2. Being a Thermodynamic System in which it is enclosed by rigid immovable walls of which neither mass nor energy can flow through.
I believe in this case although not stated that it would refer to a Thermodynamic System which would leave you with the only plausible answer as ENERGY AND MATTER CANNOT ENTER OR LEAVE.
None of the other answers make sense. Even if it were referring to Physical. Physical does not react with anything at all. An as you can see Thermodynamic does not allow for anything to pass through or leave.