- A Secrete digestive enzymes into the respiratory tract
- B Generate sound during speech by vibrating with airflow
- C Sweep mucus and trapped particles away from the lungs
- D Absorb oxygen directly into the underlying blood vessels
Correct answer: C. Sweep mucus and trapped particles away from the lungs
Explanation: Ciliated epithelium lines much of the respiratory tract; coordinated beating of cilia moves a layer of mucus, along with trapped dust and microbes, away from the lungs and toward the throat.
Concept context
The four basic animal tissue types (epithelial, connective, muscular, neural) and the cockroach as a model organism for organ-system level organisation.