Final answer:
Amphibians are unusual vertebrates because they can uptake water from the environment through their skin, reabsorb water from their urinary bladder, and produce diluted urine to excrete waste.
Step-by-step explanation:
Amphibians have a unique ability to uptake water from the environment through their skin by osmosis. Their skin is moist and permeable, allowing for the absorption of water. This is important for their survival in both aquatic and terrestrial environments.
Amphibians also have the ability to reabsorb water from their urinary bladder. This allows them to conserve water and prevent dehydration, especially during times of water scarcity.In addition, amphibians produce diluted urine to excrete waste. This adaptation helps them maintain appropriate solute concentrations in their bodies and prevent excessive water loss.