This is an experiment on how planaria regenerate body parts and an explaination as to how the experiment was performed.

Essay by brattlillyUniversity, Bachelor'sA+, January 2004

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This experiment was undertaken to evaluate the varying degrees and limitations of regeneration using flatworms. Regeneration occurs in many levels throughout the animal kingdom. The flatworms demonstrated substantial healing abilities once the surgery had been performed. Total regeneration and reproduction had occurred resulting in three separate flatworms from one that had been cut through three quarters of the length of the body.


Planaria belong to the phylum Platyhelminthes (flatworms). They are free-living, flat bodied, freshwater animals that demonstrate the notable ability to regenerate their lost body parts. "In some genera, when a single individual is divided into two or more parts, each part can regenerate an entirely new flatworm" (Johnson). In addition to reproducing asexually by regeneration, the hermaphroditic planaria feature an internal reproductive system. When two flatworms join, each exchanges sperm and fertilizes the other's eggs. Their simple body plan also allows them to regenerate complete bodies from mere fragments by asexual reproduction.

Their body plan consist of a simple nervous system that includes a primitive brain, central nervous system, muscles, an internal reproductive system, intestines and an excretory system that includes specialized flame cells. In this experiment, a flatworm was used to assess the regeneration process over the course of three weeks.

Materials and Methods

·Remove ice container from freezer, snap it shut and place on the stage of a dissecting microscope.

·With a camel's hair brush carefully place one flatworm on the center of the ice container surface.

·Wait until the animal has flattened out.

·Use a clean, sharp razor blade to make a quick cut from the tip of the head area (between the eyespots) through three-quarters the length of the flatworms body allowing the pharynx to go to one side or the other.

·Cut will have to be renewed every twelve hours for...