The diagram illustrates the life cycle of a frog.
Overall, the frog undergoes significant changes as it develops from an egg into an adult. This process involves several stages, including egg, tadpole, froglet, and finally adult frog, and takes approximately 1 to 4 years to complete.
In about 6-21 days, the egg develops under the water surface, where the roe is protected by a jelly-like natural coat. Then, between 6 and 9 weeks, the egg evolves into a tadpole. At this stage, the tadpole moves like a common fish, using its tail; subsequently, it develops hind legs first, and only after this develop all four legs (approximately in 3-6 weeks).
After about 3 weeks, the tadpole develops into the froglet; now it looks much more like an adult frog; nonetheless, it is not yet fully developed. The froglet has a remaining tail. Its nutrition consists of small plants, its lungs are developed, and a significant improvement is the ability to jump. After a year (2-4 years old), the tail falls off, and the froglet finally becomes an adult frog which consumes insects and small animals and has the ability to move from water onto the ground.