Two Peas in a Pod

By Paul Welsh

Abstract

Based on an actual event, this case study focuses on some of the problems associated with reproductive technologies. It tells the story of the "Joneses," who after in vitro fertilization treatment, discover that their fraternal twins are less similar than one would expect two brothers to be. Students work in teams to unravel the mystery using DNA profiling. Related issues that can be explored include the right to medical information, the implications of human error, and racism.

Download Case

Date Posted

10/20/2003

Overview

Objectives

Review the terms and concepts of fertilization, twinning, fraternal vs. identical twins, in vivo and in vitro fertilization, and DNA profiling.
Interpret evidence from several single locus DNA gel electrophoresis tests.
Understand the benefits and limitations of reproductive technology.
Explore legal and ethical issues implied by the use of reproductive technology.

Keywords

Twins; twinning; fertilization; heteropaternal superfecundation; reproductive technology; in vitro fertilization; IVF; gel electrophoresis; DNA profiling; paternity; maternity; medical error; bioethics; medical ethics

Subject Headings

Biology (General)

Biotechnology

Molecular Biology

EDUCATIONAL LEVEL

High school, Undergraduate lower division

FORMAT

PDF

TOPICAL AREAS

Ethics, Legal issues, Social justice issues

LANGUAGE

English

TYPE/METHODS

Interrupted, Role-Play, Trial

Teaching Notes & Answer Key

Teaching Notes

Case teaching notes are protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, purchase a subscription here.

Teaching notes are intended to help teachers select and adopt a case. They typically include a summary of the case, teaching objectives, information about the intended audience, details about how the case may be taught, and a list of references and resources.

Download Notes

Answer Key

Answer Keys are protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, purchase a subscription here.

Download Answer Key