Talking about stem cells in the classroom, with activities and discussion questions

Stem cells are one of the few biology topics where students arrive already holding opinions. Some have seen a clinic ad promising to fix a grandparent's knees. Some have heard the embryo debate at home or at their place of worship. A few know someone who received a bone marrow transplant. That makes the topic tricky to teach and very good for teaching, because it ties cell biology to law, medicine, money and personal values in a single unit.

This guide is for middle and high school teachers, intro college instructors and students working on their own. It is mostly lists, so take what fits your class.

What students should leave knowing

1. A stem cell can both copy itself (self-renewal) and produce more specialized cells (differentiation). Our explainer on what makes a stem cell a stem cell is written at about the right level.
2. Potency comes in degrees: totipotent, pluripotent, multipotent. Most stem cells in an adult body are multipotent.
3. Embryonic stem cells come from early embryos, typically ones donated after IVF treatment. Induced pluripotent stem cells are made by reprogramming adult cells.
4. Blood stem cell transplants, from bone marrow, blood or cord blood, are long-established medicine. Most other stem cell treatments are still in clinical trials.
5. "Approved," "in a trial" and "sold by a clinic" mean very different things.
6. Ethical questions do not vanish when the science changes. They move.

A short history to teach from

• 1981: Mouse embryonic stem cells are first grown in the lab, by Martin Evans and Matthew Kaufman in Britain and, separately, Gail Martin in California.
• 1996: Congress passes the Dickey-Wicker Amendment, which bars federal funding for research that creates human embryos for research or destroys them. It has been renewed in spending bills every year since.
• 1998: James Thomson's lab at the University of Wisconsin derives the first human embryonic stem cell lines.
• August 9, 2001: President George W. Bush announces that federal money can fund research only on human embryonic stem cell lines that already existed by that date. The administration said more than 60 lines qualified; far fewer proved usable.
• 2004: California voters approve Proposition 71, creating a state stem cell institute funded outside the federal limits.
• 2006 and 2007: Shinya Yamanaka's lab reprograms mouse, then human, cells into induced pluripotent stem cells.
• March 9, 2009: President Barack Obama signs Executive Order 13505, lifting the 2001 limit. NIH guidelines issued that July set rules for which lines qualify, including documented consent from the people who donated the embryos, and NIH started a registry of eligible lines.
• 2012: Yamanaka and John Gurdon share the Nobel Prize in Physiology or Medicine.
• 2014: A patient in Japan receives the first transplant of cells made from iPSCs, a retinal patch for macular degeneration.

A useful point for older students: federal rules govern federal money only. Private funders and some states were never bound by the 2001 limit, which is one reason the research continued through those years. Policy has also shifted with administrations and court cases, so have students check the current rules on the NIH site rather than relying on a textbook.

How iPSCs changed the debate, and how they did not

When induced pluripotent stem cells arrived, some commentators declared the embryo debate over. It was not quite that simple, and the reasons make good discussion material:

• Researchers still compare iPSCs against embryonic stem cells, which remain the reference standard for what "pluripotent" should look like.
• iPSCs raise questions of their own. A blood sample can become any tissue, so what exactly is a donor agreeing to?
• In mice, researchers have turned iPSCs into eggs. No one has yet made a mature human egg this way, but students can ask what rules should apply if someone does.
• Stem cells can now be assembled into structures that resemble early embryos. In 2025 the ISSCR updated its guidelines on these embryo models, saying they must never be transferred to a uterus or grown in the lab to the point of potential viability.
• Every iPSC line carries its donor's full genome, which raises privacy questions familiar from consumer DNA testing.

Teaching the clinic problem

Students are far more likely to meet stem cell marketing than stem cell science. The FDA has issued a consumer alert on regenerative medicine products, and the ISSCR has long warned about clinics selling unapproved treatments. Our post on unproven stem cell clinics covers the warning signs in depth. A short version for the board:

• The same cells are offered for many unrelated conditions.
• Evidence comes as testimonials and videos, not published results.
• Patients pay cash, sometimes for something called a "trial."
• The cell source is vague ("your own stem cells") and the risks go unmentioned.
• A listing on ClinicalTrials.gov is presented as proof of approval. It is not; registration is not review.

Consent and donation

These cases help students see that stem cell ethics is about people as much as embryos:

• Henrietta Lacks. Cells from her cervical tumor, taken at Johns Hopkins in 1951 without her knowledge, became the HeLa line used in labs worldwide. In 2013 the NIH reached an agreement with her family on access to the line's genome data.
• IVF embryos. People who finish IVF treatment typically choose among continued storage, disposal, donation to another patient, or donation to research.
• Cord blood. Families can donate to a public bank or pay for private storage, and the two serve very different purposes.
• Living donors. Adults can join a registry such as the one run by NMDP to donate blood stem cells to a stranger.

Classroom activities

1. Potency sort (20 minutes, grade 7 and up). Give groups cards naming cell types and have them build a family tree starting from a fertilized egg. Then hand out a card that says "iPSC" and ask where it goes. Its arrow points back up the tree, which is the whole idea in one move.
2. Timeline walk (30 minutes). Post the history dates around the room. Groups rotate and add a sticky note to each: who gained, who objected, what changed in the lab.
3. Ad autopsy (40 minutes). Write a fictional clinic ad yourself, rather than using a real business's, and have students mark every claim, list what is missing, and check the claims against the FDA's list of approved cell and gene therapies.
4. Write the consent form (45 minutes, grade 10 and up). Groups draft a one-page form for a researcher who wants to make iPSCs from a donor's blood. Must the donor be told the cells could be sold? Made into brain organoids? Shared with labs overseas?
5. Structured academic controversy (two periods). Pairs argue one side of "Should federal funds support research on embryos left over from IVF?", then switch sides, then try to write a joint statement. The goal is accuracy about the other view, not a winner.
6. Follow the headline (homework). Students find a news story about a stem cell study and trace it to the source paper or trial record. Was it mice, cells in a dish or people? How many?
7. Career cards (20 minutes). Cards describe roles such as cell therapy manufacturing technician, clinical research coordinator, bioethicist, genetic counselor and regulatory affairs specialist. Students place each role at a stage between lab bench and patient. Our page on careers in the life sciences has more detail on each path.

Discussion questions

Middle school

• If a cell can become many things, why does a cut on your skin heal as skin and not as bone?
• Why might a scientist grow heart cells in a dish instead of studying a real heart?
• What would you want to know before giving cells for research?

High school

• Is there a moral difference between using an embryo that would otherwise be discarded after IVF and creating one for research?
• If iPSCs can do most of what embryonic stem cells do, should embryonic stem cell research stop? What would be lost?
• Who should decide what happens to cells after they leave your body: you, the researchers or the law?
• Why might a clinic sell "stem cell therapy" for conditions with no approved treatment? Whose job is it to stop that?
• The federal Right to Try Act of 2018 lets some patients with life-threatening conditions seek certain experimental drugs outside trials. Where should the line be between hope and protection?

Advanced classes

• Federal funding rules changed in 2001 and again in 2009. Should research policy depend on who is president?
• Some cell therapies cost hundreds of thousands of dollars. Who should pay, and what happens in countries that cannot?
• An embryo model is made from stem cells, not from sperm and egg. Should it be treated like an embryo? At what point?
• Should donors share in the profits if their cells lead to a product?

Ground rules that help

• Separate questions of fact (what does the research show?) from questions of value (what should we do?).
• Ask students to state the strongest version of a view they disagree with before responding to it.
• Offer anonymous written questions for topics close to home, such as infertility, illness or faith.
• Never ask students to share family medical history.
• Accept "I'm not sure yet" as a legitimate position.

Sources worth bookmarking

• NIH Stem Cell Information: plain-language basics, plus links to the registry of human embryonic stem cell lines eligible for NIH funding.
• ISSCR: the international society's guidelines for stem cell research and clinical translation, last revised in full in 2021, with the embryo model update in 2025.
• About Stem Cells: the ISSCR's public education site, which began as A Closer Look at Stem Cells. Old closerlookatstemcells.org links forward there. Its patient guide and list of questions to ask a clinic work well as reading assignments.
• The FDA's consumer alert and its list of approved cellular and gene therapy products, for checking any claim that a treatment is "approved."
• ClinicalTrials.gov, for the follow-the-headline activity.
• The Nobel Prize site's 2012 page, which includes accessible explanations of Yamanaka's and Gurdon's work.

One last check before using any video or article in class: look at the date. The field moves quickly enough that a 2015 explainer will miss approvals that have since happened, such as the FDA's December 2024 approval of Ryoncil, the first FDA-approved mesenchymal stromal cell therapy, and may still describe as "promising" ideas that later failed in trials.