Sea stars contain a __________, which they evert outside their body to begin digesting food externally.

One of the most primitive living Vertebrates, this organism has no true jaw structure, lacks paired fins, and is ectoparasitic on other fish:

This structure draws water into a seastar:

Largest, most successful class of animals on Earth:

These are paddle-like structures attached to the segments of a marine-dwelling segmented worm:

The phylum associated with ferns is:

Arthropods with 4 pairs of walking legs:

Cilia sweep the released mature oocyte from an ovary into the

Human reproduction can result in a

A dual-chamber pacemaker is surgically placed in a patient’s chest. Wires then carry pulses to the right atrium and the right ventricle. Why would the pulses be carried to the right chambers of the heart and not the left chambers?