1. Multiple Choice: Which of the following structures is responsible for the exchange of gases in the lungs? A) Alveoli B) Bronchi C) Trachea D) Diaphragm Correct Answer: A) Alveoli Rationale: The alveoli are the tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide occurs, which is essential for respiration. 2. True/False: The cardiac cycle is completed in one heartbeat. Answer: True Rationale: The cardiac cycle, which includes the stages of atrial systole, ventricular systole, and diastole, occurs within a single heartbeat. 3. Fill-in-the-Blank: The _______ artery is the only artery that carries deoxygenated blood. Correct Answer: Pul