Amphibian skin is ____.

Amphibian skin is ____.

• A. Thick and dry
• B. Thin and moist to allow gas exchange
• C. Opaque and tough
• D. Covered with scales

Answer: (B)

Amphibian skin is thin and moist to allow gas exchange. Its permeability lets oxygen diffuse into the blood and carbon dioxide diffuse out, and keeping the surface damp is essential for that diffusion to occur. Mucous glands help maintain moisture, which is why these animals are typically found in moist environments or near water. A thick, dry barrier would block diffusion and water uptake, and scales are not a typical feature of most amphibians, so describing the skin as thin and moist captures how they exchange gases most effectively.

Amphibian skin is thin and moist to allow gas exchange. Its permeability lets oxygen diffuse into the blood and carbon dioxide diffuse out, and keeping the surface damp is essential for that diffusion to occur. Mucous glands help maintain moisture, which is why these animals are typically found in moist environments or near water. A thick, dry barrier would block diffusion and water uptake, and scales are not a typical feature of most amphibians, so describing the skin as thin and moist captures how they exchange gases most effectively.