What type of mutation has occurred in figure 12-3? 
Answer= substitution
        
             
        
        
        
A) A sound wave
The other 3 create mutations, are cells are hit by sound waves all the time and experience no mutations because of it
        
             
        
        
        
B, because in all truth and honesty, stress is truly inevitable. Also, use process of elimination. I hoped that helped :)
        
             
        
        
        
Answer:
Actin filaments return to their original positions (does not occur in muscle contraction, according to the sliding filament model).
Explanation:
 
        
             
        
        
        
C paired nitrogen bases. hope i help don't forget to go subscribe to king kevin on youtube its my channel i have 840 subscribers plz go subscribe and be active thank you.