Introduction: the frogs are some of the few remaining members of the amphila a group which flourished 250 million years ago.other present-day members of the group are the toads newts and salamanders.
The life cycle of a frog consists of three stages egg, larva, and adult. As the frog grows, it moves through these stages in a process known as metamorphosis. Frogs are not the only animals to undergo metamorphosis; most other amphibians also undergo remarkable changes throughout their life cycles, as do many species of invertebrates. During metamorphosis, two hormones, prolactin and thyroxine, control the transformation from egg to larva to adult.
At approximately 12 weeks of age the tadpole's gills and tail have been fully absorbed into the body meaning that frog has reached the adult stage of its life cycle. It is now ready to take a journey out onto dry land and in time repeat the life cycle.
Many species lay their eggs in calm water among vegetation, where the eggs can develop in relative safety. The female frog lays numerous eggs in masses that tend to clump together in groupings known as spawn. As she deposits the eggs, the male releases sperm onto the eggs and fertilizes them
