As part of your independent study in field biology,you are sent to a small,inland sea.In one of your samples,you discover a small eel-like creature.It has a stiff,rod-shaped structure running the length of its dorsal side,with a line of nervous tissue running along with it.You would begin the process of classifying this organism by placing it in phylum:

Question

Quizplus · Accepted Answer

The stiff, rod-shaped structure with a line of nervous tissue along its length indicates that the organism has a notochord, which is a defining characteristic of the phylum Chordata. Vertebrata is a subphylum within Chordata, but not all chordates have a backbone, so it would be premature to place this organism specifically in Vertebrata without further information. Arthropoda, Cnidaria, and Mollusca do not have notochords, so they can be ruled out.

As Part of Your Independent Study in Field Biology,you Are