The thermal energy can be defined as the type of kinetic energy which is generated due to the motions of the particles. This motion generates a temperature which can be measured easily. The type of thermal energy which flows from one substance to another when the temperature of the two substances is different is known as heat.
Hence, the blank can be filled with 'heat'.
 
        
                    
             
        
        
        
Answer:
<h2>They are classified on the basis of their cell wall composition and as well as by the reaction to the Gram stain test.
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Explanation: 
Most bacteria are classified into two main categories
i) Gram positive bacteria and ,
ii) Gram negative bacteria.  
They are classified on the basis of their cell wall composition and as well as by the reaction to the Gram stain test.
 Gram positive bacteria's characteristics
  ii) they have cell walls composed mostly of  peptidoglycan.
i) stain purple after Gram staining.
 Gram negative bacteria's characteristics.  
i) they have cell wall only a thin layer of peptidoglycan and an outer membrane with a lipopolysaccharide component.
ii) stain red or pink after Gram staining.  
 
        
             
        
        
        
<span>Ribosomes are the protein builders or the protein synthesizers of the cell. They are like construction guys who connect one amino acid at a time and build long chains. Ribosomes are special because they are found in both prokaryotes and eukaryotes.</span>
        
                    
             
        
        
        
Answer:
Because melting can be reversed ( freezing )
Explanation:
Physical change is a change that can be reversed
 
        
             
        
        
        
Answer:
Explanation:
 A boundary that distinguishes inside from outside the cell yet allows materials to enter or leave the cell.
The cell needs a barrier for protection, rigidity and also for easy transportation.