(2) The tail roots of tadpoles began to swell, the outer gills disappeared, the hind limbs grew, and the ends differentiated into five toes.
(3) Tadpoles have forelimbs, which are similar to hind limbs, but the hind limbs are stronger and the tail does not fall off.
(4)? The tail is close to disappearing, similar to a frog, and the body is dark green and smaller.
(5)? a tadpole is transformed into a frog.
Extended data:
Tadpole (tadpole in English), written as "Kedou" in ancient times, is the larva of frogs and toads, also called toad ball. The newly hatched tadpoles are spindle-shaped, with no limbs, mouth and inner gills, long tail, flat side and branched outer gills on both sides of the head, which are adsorbed on aquatic plants and fed by the remaining yolk in the body. Mainly in groups. When tadpoles mature, they begin to lose their shape, gradually grow limbs, and then (for frogs and toads) gradually degenerate their tails through apoptosis (controlling cell death).
References:
Baidu encyclopedia-tadpoles