Answer:
Mitochondria
Explanation:
its the powerhouse of the cell ;)
just messing with you. But in reality, the mitochondria converts food to energy in the cell.
Lactic acid buildup when you’re exercising causes a build up of oxygen. Your body cannot break down glucose in the blood. So, your heart beat increases because there is more oxygen than normal needing to be pumped throughout the body.
In short terms: because your heart needs to pump more oxygen, it is pumping faster causing a faster heart rate.
bis an example of intracelluar, not inter, so b is your correct answer
Scales of a fish, I kind of read or heard people getting drafts of fish skin which might be the same.
