- A Spiracles
- B Ostia
- C Nephridiopores
- D Stomata
Correct answer: A. Spiracles
Explanation: Cockroaches respire through a network of tracheal tubes that open to the exterior through small pores called spiracles, delivering oxygen directly to tissues.
Concept context
The four basic animal tissue types (epithelial, connective, muscular, neural) and the cockroach as a model organism for organ-system level organisation.