What feature is specialized about amphibian skin?

What feature is specialized about amphibian skin?

• A. Its skin is specialized for respiration and moisture absorption.
• B. It is covered in scales.
• C. It is used for vitamin synthesis.
• D. It is fused to the underlying muscles.

Answer: (B)

Amphibian skin is specialized for respiration and moisture absorption. The skin is thin, moist, and richly vascular, allowing oxygen and water to diffuse directly through it into the body and carbon dioxide out. This cutaneous respiration works alongside lungs and is especially important in damp environments, so maintaining a moist surface is crucial. If the skin were covered in scales, that diffusion and water uptake would be hindered, which is why amphibians typically lack scales. The other ideas—synthesis of vitamins or the skin being fused to underlying muscles—don’t describe what the skin actually does.