Biology · 11th Grade · Inheritance and Variation · Weeks 10-18

Cloning and Reproductive Technologies

Discusses different types of cloning (reproductive and therapeutic) and other assisted reproductive technologies, along with their ethical dimensions.

• Common Core State Standards
• HS-LS3-1
• HS-ETS1-3

About This Topic

This topic addresses one of the most ethically complex frontiers in modern biology. Students distinguish between reproductive cloning, which aims to produce a genetically identical organism, and therapeutic cloning, which generates stem cells for medical research without ever implanting an embryo. Understanding this distinction is essential for HS-LS3-1, which asks students to connect DNA structure to cellular function, and HS-ETS1-3, which requires evaluating potential solutions to complex problems.

The topic also surveys assisted reproductive technologies such as in vitro fertilization, intracytoplasmic sperm injection, and preimplantation genetic diagnosis. These procedures are increasingly common in American families, making the content personally relevant. Students explore the scientific procedures alongside societal debates about the moral status of embryos, genetic selection, and equitable access to reproductive technology.

Active learning is especially valuable here because the subject demands more than factual recall , it requires students to construct and defend arguments using scientific reasoning. Structured academic controversy and deliberative discussion activities build both content knowledge and the civic competencies that NGSS science-and-engineering practices emphasize.

Key Questions

1. Differentiate between reproductive cloning and therapeutic cloning.
2. Analyze the ethical arguments for and against human reproductive cloning.
3. Evaluate the potential benefits of therapeutic cloning for medical research.

Learning Objectives

• Compare and contrast reproductive cloning and therapeutic cloning, identifying key differences in their purpose and outcomes.
• Analyze the ethical arguments surrounding human reproductive cloning, citing scientific, moral, and societal considerations.
• Evaluate the potential medical benefits of therapeutic cloning for treating diseases and advancing regenerative medicine.
• Explain the scientific principles behind assisted reproductive technologies such as IVF and ICSI.
• Critique the societal implications of preimplantation genetic diagnosis, including issues of genetic selection and access.

Before You Start

Cellular Biology and Differentiation

Why: Understanding that cells have specialized functions and can develop from less specialized cells is foundational to grasping the concept of stem cells and cloning.

Basic Genetics and DNA

Why: Students need to know that DNA carries genetic information and is passed from parents to offspring to understand the concept of genetic identity in cloning.

Key Vocabulary

Reproductive Cloning	A process that creates a genetically identical copy of an existing organism, with the goal of producing a whole new individual.
Therapeutic Cloning	A process that creates a cloned embryo for the purpose of harvesting stem cells, which can then be used for medical research or treatment without implanting the embryo.
Somatic Cell Nuclear Transfer (SCNT)	The laboratory technique used in cloning, where the nucleus from a somatic cell is transferred into an enucleated egg cell.
In Vitro Fertilization (IVF)	A medical procedure where an egg is fertilized by sperm outside the body, in a laboratory dish.
Preimplantation Genetic Diagnosis (PGD)	A genetic test performed on embryos created through IVF before implantation, to screen for specific genetic disorders or chromosomal abnormalities.

Watch Out for These Misconceptions

Common Misconception

Clones are identical in every way, including personality and behavior.

What to Teach Instead

Clones share nuclear DNA, but gene expression is shaped by environment, epigenetics, and lived experience. Dolly looked and behaved differently from her genetic donor. Using identical twins , natural clones , as a case study helps students see that shared DNA does not produce identical people.

Common Misconception

Therapeutic cloning produces a living baby that is then harvested for parts.

What to Teach Instead

Therapeutic cloning creates an embryo in a lab dish that is never implanted. Stem cells are harvested at the blastocyst stage, before any tissues or organs form. Role-play activities that trace the actual lab steps help students distinguish between therapeutic and reproductive cloning procedures.

Active Learning Ideas

Structured Academic Controversy: To Clone or Not to Clone

Students are assigned a position , for or against human reproductive cloning , and research evidence from both scientific and ethical domains. After presenting their assigned stance, groups switch sides and engage the strongest counterarguments, culminating in a consensus statement about appropriate regulatory limits.

60 min·Small Groups

Case Study Analysis: A History of Cloning Milestones

Pairs receive a timeline card set covering Dolly the sheep (1996), the first cloned human embryo for research (2001), and more recent primate cloning. They sequence the cards, annotate the scientific significance of each milestone, and identify which ethical debates each event triggered.

35 min·Pairs

Gallery Walk: Benefits and Risks of Reproductive Technologies

Groups create two-sided posters for one assisted reproductive technology , IVF, surrogacy, preimplantation genetic diagnosis, or somatic cell nuclear transfer. One side presents scientific benefits; the other presents societal risks. Students circulate and add sticky-note comments before a whole-class debrief on common themes.

45 min·Small Groups

Think-Pair-Share: Who Decides?

Students respond individually to a scenario: a fertility clinic offers couples the option to screen embryos for the BRCA1 gene. They pair to compare reasoning, then the class discusses the distinction between medical necessity and genetic enhancement.

20 min·Pairs

Real-World Connections

• Researchers at the Oregon National Primate Research Center have used SCNT to create genetically identical rhesus monkeys, which serve as valuable models for studying human diseases like Alzheimer's and Parkinson's.
• Many fertility clinics across the United States offer IVF and PGD services to help individuals and couples overcome infertility or screen for genetic conditions before pregnancy.
• The debate over human cloning has influenced public policy and scientific funding, with many countries, including the U.S., having laws that prohibit or restrict human reproductive cloning.

Assessment Ideas

Discussion Prompt

Pose the following to students: 'Imagine you are on a bioethics committee reviewing a proposal for human reproductive cloning. What are the top three scientific arguments for and against it? What are the top three ethical arguments for and against it? Be prepared to defend your committee's recommendation.'

Quick Check

Provide students with short case studies. For each case, ask them to identify whether it involves reproductive cloning, therapeutic cloning, or an assisted reproductive technology like IVF. Then, ask them to state one key ethical consideration for that specific case.

Exit Ticket

Ask students to write down the primary goal of reproductive cloning and the primary goal of therapeutic cloning. Then, have them list one potential medical application for stem cells derived from therapeutic cloning.

Frequently Asked Questions

What is the difference between reproductive cloning and therapeutic cloning?

Reproductive cloning transfers a cloned embryo into a uterus to produce a live organism. Therapeutic cloning creates an embryo in the lab solely to harvest stem cells for medical research. The embryo in therapeutic cloning is never implanted, so it never develops into a living organism. The biological procedures are similar; the purpose and endpoint differ completely.

Why is therapeutic cloning controversial in the United States?

Some people believe a human embryo, even at the blastocyst stage, deserves full legal and moral protection. Others argue the medical potential , treating diseases like Parkinson's or type 1 diabetes , justifies early embryo research. U.S. federal funding rules for this research have shifted with each administration, reflecting the unresolved public debate.

How can active learning help students engage with the ethics of cloning?

Ethical debates about cloning require separating scientific facts from value judgments, a skill that benefits from practice. Structured academic controversy and role-play activities give students a framework to practice evidence-based argumentation, build empathy for multiple perspectives, and reach their own reasoned conclusions rather than absorbing a teacher's view.

What is somatic cell nuclear transfer (SCNT) and how is it used?

SCNT removes the nucleus from an egg cell and replaces it with a nucleus from a donor's body cell. The egg is then stimulated to divide as if it had been fertilized. Both Dolly the sheep and human therapeutic cloning research use this technique. The resulting embryo is genetically identical to the nucleus donor.