Answer:
There is an increase in the number of breaths per minute as activity increases because:
As activity increases, the oxygen needs of cells increase.
Explanation:
<u>When we exercise, our muscles work harder than they do when our bodies are resting. For that reason, the muscle cells need more oxygen - think of oxygen as the fuel we consume; the more we move, the more fuel we need. To provide that extra oxygen the cells need so much, we begin to breathe faster. For that reason, the best option for the question above is: as activity increases, the oxygen needs of cells increase.</u>
