Classification

question 47

Multiple Choice

Classification. Respond to the following statements in reference to the five animal phyla listed below.
-Trilobites were members of this phylum.

• A)Annelida
• B)Arthropoda
• C)Mollusca
• D)Echinodermata
• E)Cnidaria

---

Definitions:

Digestive Tract

The series of organs through which food passes, nutrients are absorbed, and waste is expelled; also known as the gastrointestinal tract.

Muscularis Layer

A layer of muscle found in various organs, including the stomach and intestines, which aids in movement and function.

Smooth Muscle Fibers

The individual muscle cells or fibers that make up smooth muscle, characterized by their spindle shape and lack of striations.

Circular Smooth Muscle

Smooth muscle fibers arranged in circular bands in various organs, such as the intestines, aiding in the constriction and movement of content.