Question

why might amphibians show signs of environmental stress earlier than other groups of animals?

Explanation:

Amphibians have a dual - life cycle (aquatic larvae and terrestrial adults) and permeable skin. Their skin absorbs water and chemicals, so pollutants or habitat changes in water/land affect them. Also, they are sensitive to temperature and moisture changes. These factors make them detect environmental stress earlier than many other animals.

Answer:

Amphibians show earlier environmental stress signs due to: 1. Permeable skin (absorbs pollutants/toxins from water/air). 2. Dual - habitat dependence (aquatic larvae, terrestrial adults; changes in either habitat impact them). 3. Sensitivity to climate (temperature, moisture changes affect their physiology/behavior). 4. Vulnerable life cycle (eggs lack hard shells, larvae are aquatic - prone to habitat degradation).