試題詳解

7.The hormone prolactin, found in distantly related vertebrates, exerts different effects in different species. From an evolutionary standpoint, this is an indication that hormonal regulation
(A) is an ancient process whose function diversified through evolution.
(B) was a recent evolutionary adaptation.
(C) is required only of nonsteroid hormones.
(D) is not critical to all animals.
(E) was not required in fish and amphibians.