Answer:
frog
Explanation:
The tadpole (frog) is born from the egg, the larval form of frogs. They live in an aquatic environment, have gills and a highly developed tail, in addition to having no legs. They also have a small mouth adapted to their feeding, which normally occurs through filtration and scraping processes of the substrate. At this stage of life, the heart of these animals has only one atrium and one ventricle, being similar to that of fish.
During the process of metamorphosis of frogs, tadpoles gain their limbs. Initially, the hind limbs develop in the region close to the beginning of the tail and, later, the anterior limbs develop. There is also the appearance of the lungs and changes in the structure of the heart, which now has two atria and a ventricle. As soon as the lung is formed, the animal can leave the interior of the water. Finally, tail resorption occurs and the animal starts to show the morphological characteristics of an adult, although they are still small.
