Answer:
the cycle of night and day
hope this helps :p
Explanation:
I am pretty sure that if muscle cells failed to function properly the thing that would happen is being revealed by the first option : A. The muscles will not work. I choose this one because as you know muscles are made of muscle tissue and if cells fail it won't functionate at all.
C because ye ye ye ye ye ye ye
6. is Saprophytic
7. Parasitic
8. Either mimetic or mutualistic i think mutualistic