The picture shows the four-stage life cycle of a frog. Overall, it took a long time for a frog to fully develop, starting from eggs, through several changes in appearance and habitat, to an adult frog.
The process begins with eggs being laid in large quantities and protected by a jelly-like substance on the surface of a pond or lake where the water is still and shallow. After 6 to 21 days, the eggs hatch and tadpoles emerge, whose tails and movement resemble a fish and feed on algae and small plants. This second stage lasts up to 9 weeks, during which time the tadpole develops rear and all four legs within 3 to 6 weeks.
In the third stage, the tadpole grows into a froglet, which still has the tail and unchanged diet, but now it can jump with longer legs and its lungs are formed. The final stage occurs after 12 weeks when the froglet matures into an adult frog. During this stage, the adult frog becomes an amphibian with a disappeared tail, living in a mixed environment with small bodies of water or nearby vegetation and eating insects and small animals. The cycle repeats after 2 to 4 years when the adult frog mates, returns to a pond or lake and lays eggs there.