A) no fossils of soft-bodied animals
B) a modern bird having reptile-like scales on its legs
C) radioactive dating of rocks showing that rocks closer to the Earth’s surface are
younger than lower rock strata
D) diverse fossils of mammals in Precambrian rock
A trend first observed in the evolution of the earliest tetrapods was _____.
A) the appearance of jaws
B) feet with digits
C) the mineralization of the endoskeleton
D) the amniotic egg
Use the following information to answer the question(s) below.
An elementary school science teacher decided to liven up the classroom with a
saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher
proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided
to stock the tank with various marine invertebrates, including a polychaete, a siliceous
sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial
hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod