The biological process of a tadpole turning into a frog is called metamorphosis, which is an amazing transformation. Here the metamorphosis process were broken down to six stages for easy understanding. From an egg stage to an adult.
Frog’s always lays eggs as a mass. Each of those black dots is made up of a bunch of cells which will grow into a tadpole. Depending on the species, these group of eggs or the egg masses can be made up of several hundred eggs.
Within a few days, the eggs develop into tadpoles, which looks like a small fish. Tadpoles have tails and live underwater. The tadpole’s have horny teeth to tear up plants. Not all tadpoles goes to next stage, since some of those were eaten by other living creatures in water. Only left behind goes to next stage. After a few weeks, a hormone in the tadpole’s thyroid gland starts metamorphosis.
Tadpole with hind legs
Over about a one day (24 hour period), the tadpole develops into a frog with two hind legs grown. This means almost every organ has to change, so that the tadpole can go from living underwater to living on land as an adult frog.
Tadpole with front and hind legs
In this stage, after the hind legs have started to form, a pair of front legs will begin to develop and its tail will start to vanish. You might also notice that the tadpole has started to form a frog-like face. The tadpole’s skull is made out of cartilage (our ears and nose are made out of same stuff) but here, during metamorphosis, the cartilage is replaced with bone.
Froglet (or young frog)
The young frog is also called as froglet. When the tadpole reaches this stage, it is almost a full adult. In this stage the tadpole’s gills have disappeared, and its lungs have enlarged. While seeing this we can say, it is ready to leave the water and live on land. Once its tail disappears, it will become an adult frog.
This is a fully grown frog. As you have just read, frogs go through different stages to reach this phase. The horny teeth of tadpole disappear and tongue muscles develop to catch insects. In tadpole stage it has large intestine, which is important for digesting algae and plants, and it shrinks to suit the frog’s meat-eating diet.