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A Mini-Lesson



BSCS Blue Version
Larry Flammer

Click Here for PDF copy
of this Lesson




Asexual Repro.
Molecular basis
Special Projects


This lesson is easily done in any secondary life science or biology classroom. Students can "create lives" by cutting little flatworms in half, watch how each part regenerate their missing parts, and thereby produce two new planarians from one. Engaging as one of the interactive lessons to introduce reproduction (planarians can reproduce by self-fissioning, as well as sexually). There are close ties here to stem cell activity, and studying the genetics of the process. Planarians can also be trained, the trained planarians chopped up and fed to untrained planarians, who now exhibit the behavior of the trained planarians! Potential for seeking the molecular basis for that learning.


1. Some organisms can reproduce asexually by fissioning.
2. The process of regeneration and some of the organisms where that can happen.
3. Insights to stem cell totipotency.


1. Live planarians (from biological supply house, or collected in local creeks)
2. Small Stacking dishes, glass slides, and razor blades
3. Cotton swabs for obtaining and moving planarians.
4. Spring water (or special littoralis solution)
5. Medium Stacking dishes for holding classroom supply of planarians (for all classes)
6. See PDF page for teaching details of "Planarian Regeneration Preparation"


PDF of student copy: "CREATE LIFE!!!":
... Preparing drawing plate for drawing the original planarian and original cut pieces, and stages of regeneration
... Preparing labels for stacking dishes
... Student Procedures for handling and cutting planarians
PDF of Wrapup: "Reproduction Lab: Planarian Regeneration"
... Final Observations and Cleanup instructions


Less than one period to do the setting up, drawing and cutting. Ten minutes every other day for about a week or two to replace water, observe and draw the growing pieces. About 30 minutes to make final observations, clean up the glassware, pool the larger crop of planarians, and answer discussion questions.

Teaching Strategy
Best time to start this lab is about a week or so before starting your unit introducing reproduction, so students can be observing their reproduction as the unit begins (very engaging).
PDF of Planarian Regeneration Preparation:
... Materials (including prep of "planarian water")
... Feeding Planarians
... Doing the Lab






Details for Planarian Studies in Regeneration and
.... Stem Cell
Biology (NABT and HHMI)
Univ. of Pittsburgh at Bradford version (BioLab 103)
Harvard version

Planarian Studies ar Univ. of Illinois
Planarian Studies by Artificial Intelligence
Stem Cell Curriculum:
https://www.nwabr.org/teacher-center/stem-cell-research - overview
Classroom Activities: Planaria Regeneration HHMI:
Planarian Regeneration and Stem Cells HHMI:
Stem Cell Resources (PDF): General info, animations, lesson plans, lab experiments, video/audio clips

Regeneration and Planarians

What you don't know about planarians

Two-headed worms 'coded': Bioelectric code behind worm self-healing manipulated
Altering bioelectric networks reveals a 'hidden code' that controls the number of heads produced after injury even in normal-appearing flatworms
Date: May 23, 2017

Links to Training Planarians: Worm Runner's Digest
A Manual of Psychological Experimentation on Planarians (from the Worm Runner's Digest series) edited by James V. McConnell: https://ase.tufts.edu/biology/labs/levin/resources/documents/PlanarianManual.pdf
Carolina Biological Planarians.
Flat worms retain memories even after decapitation:
The Memory Transfer Episode: http://www.apa.org/monitor/2010/06/memory-transfer.aspx


Some of the ideas in this lesson may have been adapted from earlier, unacknowledged sources without our knowledge. If the reader believes this to be the case, please let us know, and appropriate corrections will be made. Thanks.

1. Original lab in Molecules to Man (1963) BSCS Blue version. Modified and detailed by L. Flammer. Used every year for many years.

2. Updated and adapted to ENSI website format: April 2017 by L. Flammer.


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