Q160 / 180 · NEET 2026 (Re-NEET) · Zoology
Sponges exchange O$_2$ with CO$_2$ by __________.
- Agills
- Correct answerBsimple diffusion over their entire body surfaces
- Cmoist cuticle
- Dtracheal tubes
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
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
Hence, the correct answer is option: 'B'.