HOTS Science Primary 5 Systems

During heavy exercise, a person's breathing rate and heart rate both increase. Why must both systems work together in this way?

A To strengthen the heart and lung muscles.
B To take in more oxygen and remove carbon dioxide faster.
C To ensure the person does not get tired.
D To prevent the body from overheating.
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Worked Solution

Step 1: Muscles need more energy/oxygen during exercise. Step [2-9]: The respiratory system brings in oxygen; the circulatory system transports it. Step [2-9]: Both must increase to meet the higher demand for oxygen and faster removal of waste carbon dioxide.

Correct answer: To take in more oxygen and remove carbon dioxide faster.

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