An animal with a backbone, moist mucus-covered skin, complete metamorphosis, and life in water and on land belongs to which group?

• A. Amphibians
• B. Reptiles
• C. Mammals
• D. Fish

Answer: (A)

Amphibians fit this description because they are vertebrates with moist, mucus-covered skin and a life cycle that starts in water and often involves metamorphosis to a land-dwelling adult. The moist skin helps with gas exchange in damp environments, and the typical life pattern—eggs laid in water that hatch into aquatic larvae, which then transform into terrestrial adults—connects both habitats. This combination distinguishes them from fish (which stay in water), reptiles (with dry, scaly skin and different life cycles), and mammals (which have fur and nurse their young and do not undergo this kind of metamorphosis).