26 Q 2

What changes in egg design allowed reptiles to lay eggs on land? Why is their egg often called an "amniotic" egg? What are "amniotes"?

Reptile eggs do not need water. Their two membranes permit better exchange of oxygen and carbon dioxide than amphibian eggs, and the amnion and calcareous shell provide support and reduce desication. Many reptiles also develop the eggs within the female reproductive tract, providing greater protection. The young within the eggs can develop faster and larger because of the large yolk sac.
Amniotes are animals with amniotic eggs.

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