What are the four principal features that characterize the chordates?

Prior to the divergence of animals, an ancestor is proposed to have developed the key shared trait of all animals, the _____.

Match the major bacterial group to its description.

All arthropods _____. 1. undergo complete metamorphosis2. have jointed appendages3. molt4. have segmented bodies5. have an exoskeleton or cuticle

Cardiac muscle cells are both _____.

An illustration constructed by a biologist to depict hypothesized evolutionary relationships is a(n) _____.

Identify structure labeled C _______ .

All of these animals are mollusks except _____.

Identify the structure labeled T. _______ .

Identify the structure labeled A _______ .