Question
Sponges exchange O_2 with CO_2 by __________.
NEET
Zoology
Breathing and Exchange of Gases
2026
NEET 2026 (Re-NEET)
NEET Zoology Question (2026) — Solution
Options
- A. gills
- B. simple diffusion over their entire body surfaces
- C. moist cuticle
- D. tracheal tubes
Answer
B. simple diffusion over their entire body surfaces
Step-by-step solution
Sponges, coelenterates, and flatworms exchange O_2 with CO_2 by simple diffusion over their entire body surfaces. Gills are used by most aquatic arthropods and molluscs. Earthworms use their moist cuticle for gas exchange. Insects have a network of tubes called tracheal tubes to transport atmospheric air within the body. Answer: simple diffusion over their entire body surfaces
Related: Zoology — Breathing and Exchange of Gases · All PYQ Banks