The mitochondria because they are the energy-producers for cells
        
                    
             
        
        
        
<span>Every living organism begins life as a single cell. Unicellular organisms may stay as one cell but they grow too. Multicellular organisms add more and more cells to form more tissues and organs as they grow. </span>
        
             
        
        
        
Answer:
Option-A
Explanation:
Penicillin is an antibiotic drug that is derived from the fungal species of Penicillium molds especially the<em> Penicillium notatum</em>.  The penicillin acts by disrupting the formation of the cell wall and thus prevents the growth of the bacteria.
The discovery of penicillin was accidental when he was studying the petridish of staphylococcus and he found that due to avoidance while the experiment, molds grew in the petridish.  The area around the mold was clear and clear rings without the bacteria were easily observed. This lead to the discovery of the penicillin compound.
Thus, Option-A is the correct answer.
 
        
             
        
        
        
Answer:
D
Explanation:
Pretty sure that's the correct answer.