What characteristic do amphibians have that distinguishes them from reptiles?

• A. Cold-blooded bodies
• B. Ability to live in both water and on land
• C. Presence of scales
• D. High body temperature regulation

Answer: (B)

Amphibians are distinct from reptiles primarily because of their ability to live in both water and on land. This characteristic is crucial to their life cycle and survival; amphibians, such as frogs, toads, and salamanders, typically begin their lives in aquatic environments where they undergo metamorphosis. As they mature, many of them develop adaptations that allow them to thrive in terrestrial habitats.

This dual lifestyle is not only a fundamental aspect of their biology but also influences their respiratory systems and skin texture. Unlike reptiles, amphibians often breathe through their skin as well as their lungs, which necessitates a moist environment to facilitate gas exchange. This key characteristic of living both in water and on land sets amphibians apart from reptiles, which are fully adapted to life on land and have more extensive adaptations for a terrestrial existence.

The other characteristics, like being cold-blooded, present in both groups, and the absence of scales in amphibians compared to reptiles' scaly skin, do not serve to differentiate them effectively in relation to their habitats.