1. Which of the following structures is not part of the respiratory system? A. Larynx B. Esophagus C. Trachea D. Bronchi Answer: B. Esophagus Rationale: The esophagus is part of the digestive system, not the respiratory system. 2. Which type of epithelial tissue lines the trachea and bronchi? A. Simple squamous B. Stratified squamous C. Pseudostratified columnar D. Simple cuboidal Answer: C. Pseudostratified columnar Rationale: Pseudostratified columnar epithelium lines the respiratory tract and helps trap foreign particles. 3. Which specialized cells produce mucus in the respiratory tract? A. Goblet cells B. Cilia C. Alveolar cells D. Macrophages Answer: A. Goblet cells Rationale: Goblet cells produce mucus to trap dust and other particles in the air. 4. Which structure is responsible for gas exchange in the lungs? A. Bronchi B. Alveoli C. Trachea D. Pharynx Answer: B. Alveoli Rationale: Alveoli are tiny air sacs in the lungs where gas exchange takes place. 5. Which of the following is a function of the respiratory system? A. Regulating blood glucose levels