Diversity of Life Practice Test

Mollusks have a complete digestive tract with a distinct mouth and anus, allowing food to move in one direction through specialized regions for digestion and absorption. Many mollusks also possess a radula, a tongue-like organ with tiny teeth used to grasp and break up food before it enters the esophagus. This combination—two openings and a sequential gut with regional processing—best fits how mollusks digest food. Descriptions that involve a single-opening gastrovascular cavity or no digestive system don’t apply to mollusks.