The chart illustrates the successive stages in the life cycle of a frog. All in all, this life cycle is comprised of eight stages, from tiny eggs to a fully mature adult frog.
In the early stages, dozens of eggs are laid in water and develop into embryos. These embryos hatch into tadpoles, which attach themselves to plants. As the tadpoles grow, their bodies elongate, and their tails grow further to develop swimming possibilities, until hind legs finally emerge – marking the completion of the purely aquatic phase.
Once hindlegs have appeared, the tadpole faces dramatic changes: front legs develop internally and then break through the skin, while the tail, which has supplied energy reserves, slowly shortens and is finally lost. During this transformation, the animal transitions from gill- to lung-based breathing. When the tail has largely disappeared and all four legs are functional, the creature may be called a young frog. Continued growth and maturation produce an adult frog, capable of reproduction, which completes the cycle.