The developmental process of a frog from egg to adult is called metamorphosis. This process begins with the female frog laying eggs in water, which hatch into tadpoles. Tadpoles are aquatic and possess gills, a tail, and no legs. Over time, they undergo significant physiological changes, including the development of legs, absorption of their tails, and the transition from gills to lungs. This remarkable transformation allows the frog to adapt to a terrestrial lifestyle as an adult, showcasing the complexity of amphibian life cycles.