Tetrapods (amphibians, reptiles, and mammals) all share a common ancestor. which of these traits was not present in the common ancestor of all tetrapods (amphibians, reptiles, and mammals):
a. amniotic egg
b. vertebral column
c. digits
d. paired appendages
e, jaws

Amniotic egg.

Explanation:

Amniotic egg is the advanced evolutionary character first appeared in reptiles. These amniotic egg allows the reptiles to colonize on the dry lands. This amniotic egg is covered by hard shell in birds and reptiles.

The amniotic egg is not present in fishes and frogs as they lay their eggs in water. The amniotic egg is present in reptiles, birds and mammals. The vertebral column, paired appendages, jaws and digits are present in frogs, reptiles, birds and mammals.

Thus, the correct answer is option (a).

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.

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