Answer:
The amniotic egg was an evolutionary invention that allowed the first reptiles to colonize dry land more than 300 million years ago. Fishes and amphibians must lay their eggs in water and therefore cannot live far from water. But thanks to the amniotic egg, reptiles can lay their eggs nearly anywhere on dry land.
Step-by-step explanation:
An amniotic egg has a clump of nutrients that is used to sustain the embryo during development. This clump of nutrients is called the yolk, and the yolk sac encloses it.