Compare the development of the embryo of amphibians and reptiles.

Amphibians need water for reproduction. There eggs with a thin shell are deposited and externally fertilized. A tadpole is formed from the egg – with gills, close to fish, rather than amphibians. Gradually, with growth, the gills will disappear, and pulmonary sacs will appear. This transformation is called metamorphosis. Reptiles are independent of water, they do not need it for fertilization. Fertilization is internal, after which the reptile lays eggs on land – with a dense calcium shell. A reptile is born from an egg – this is development without metamorphosis. Viviparous reptiles are sometimes found.