The cells use more energy. The cells store more nutrients. The cells degrade more proteins. The cells divide more frequently.
I gave my students this multiple choice question: Some cells, such as human nerve and muscle cells, contain many more mitochondria than do other cells, such as skin cells. Why do some cells have more mitochondria than others?

Only one answer is correct among these 4 choices:
- The cells use more energy.
- The cells store more nutrients.
- The cells degrade more proteins.
- The cells divide more frequently.

Could you tell me which one is correct?

The cells use more energy.