Question 1: Name the two main organs involved in the cardio-respiratory system.

Answer: The heart and the lungs.

Question 2: Describe the role of the heart during exercise.

Answer: The heart pumps more blood to supply oxygen and nutrients to the muscles and remove waste products during exercise.

Question 3: Explain how the lungs help in breathing during physical activity.

Answer: The lungs take in oxygen from the air and transfer it to the blood, which is then circulated to the muscles; they also remove carbon dioxide from the blood.

Question 4: What is the function of the alveoli in the lungs?

Answer: Alveoli are tiny air sacs where oxygen is transferred into the blood and carbon dioxide is removed from the blood.

Question 5: Describe what happens to your breathing rate when you start running faster.

Answer: Your breathing rate increases to take in more oxygen and remove more carbon dioxide as your body requires more energy.

Question 6: Sketch a simple diagram of the path oxygen takes from the air to the muscles during exercise. Label the lungs, bloodstream, and muscles.

Answer: A correct sketch would show air entering the lungs, oxygen passing into the blood via alveoli, blood circulating to muscles, and oxygen being used in muscle cells.

Question 7: Explain why the heart rate increases during physical activity.

Answer: Because muscles need more oxygen and nutrients, the heart beats faster to pump more blood around the body.

Question 8: List two ways regular exercise can improve the efficiency of the cardio-respiratory system.

Answer: It can increase the strength of the heart and improve lung capacity.

Question 9: Identify the part of the heart that receives oxygen-rich blood from the lungs.

Answer: The left atrium.

Question 10: Describe how the exchange of gases occurs at the alveoli.

Answer: Oxygen passes from the alveoli into the blood, and carbon dioxide moves from the blood into the alveoli to be exhaled.

Question 11: Sketch a basic diagram showing the relationship between the heart, lungs, and blood vessels during exercise. Label each part.

Answer: A correct diagram would depict the heart in the center, with arteries and veins connecting to the lungs, showing oxygen entering the blood and carbon dioxide leaving.