Question 1: Define aerobic respiration and explain its role during exercise.

Answer: Aerobic respiration is the process of producing energy in cells using oxygen, which provides most of the energy needed during sustained exercise.

Question 2: Describe two physiological responses of the body during vigorous exercise.

Answer: Increased heart rate and faster breathing to supply more oxygen to muscles.

Question 1: A person weighing 70 kg runs for 30 minutes. If their average oxygen consumption is 3.5 liters per minute during exercise, calculate the total volume of oxygen consumed during this period. (Use the formula: Total oxygen = oxygen consumption per minute x duration in minutes).

Answer: Total oxygen = 3.5 liters/min x 30 min = 105 liters

Question 2: If the energy released from the breakdown of 1 liter of oxygen is approximately 20.9 kJ, calculate the total energy produced during the exercise described above.

Answer: Energy = 105 liters x 20.9 kJ/liter = 2194.5 kJ

Question 1: Design a simple experiment to measure how heart rate changes with different durations of exercise. Identify the independent and dependent variables and list two safety precautions.

Answer: Independent variable: Duration of exercise (e.g., 5, 10, 15 minutes). Dependent variable: Heart rate. Safety precautions include ensuring participants are medically fit for exercise and allowing rest between trials to prevent overexertion.

Question 1: What does an increase in oxygen consumption during exercise indicate about the body's energy needs?

Answer: It indicates that the body is producing more energy through respiration to meet increased muscular demands.

Question 1: Explain how the respiratory and circulatory systems work together during exercise to supply oxygen to muscles. (6 marks)

Answer: During exercise, the respiratory system increases oxygen intake through faster and deeper breathing, while the circulatory system transports oxygen-rich blood from the lungs to muscles via the heart and blood vessels. This collaboration ensures muscles receive enough oxygen for energy production and helps remove waste products like carbon dioxide.

Question 1: How can understanding the body's response to exercise be useful in designing training programs for athletes?

Answer: It helps tailor exercise intensity and duration to improve performance and prevent injury by monitoring physiological responses like heart rate and oxygen consumption.