How do frogs develop from a tadpole? How does the tail disappear?
Many animals go through big changes as they develop and grow. It is almost as if they were several kinds of animals one after another. Among animals with backbones, only some fish and frogs go through such big changes. In the transition from tadpole to frog, some body parts are broken down into small molecules and reused to build new body parts. For example, the tail is lost but legs are grown. The changes from a tadpole to a frog occur when one set of genes (call them the tadpole genes) are turned off and a new set of genes (the frog genes) are turned on. All the genes are present in the individual fertilised egg, but some just lie quietly waiting their turn to play their role in the total life span of a frog. You also have genes in you that have yet to be turned on and to help you become adults.
