What causes CO₂ in the blood to decrease?

• A. Exercise
• B. Increased cellular respiration
• C. All of the listed responses are correct.
• D. None of the listed responses is correct.
• E. Hyperventilation

Answer: (E)

Verified step by step guidance

1. Understand that CO2 levels in the blood are influenced by the balance between its production in the body and its removal through the lungs.
2. Recognize that hyperventilation involves breathing at an abnormally rapid rate, which increases the expulsion of CO2 from the body.
3. During hyperventilation, the increased rate of breathing leads to more CO2 being exhaled than is produced by cellular respiration, resulting in a decrease in blood CO2 levels.
4. Consider that exercise and increased cellular respiration typically increase CO2 production, which would not decrease CO2 levels unless accompanied by hyperventilation.
5. Conclude that hyperventilation is the specific condition that directly causes a decrease in CO2 levels in the blood by increasing the rate of CO2 removal through exhalation.