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Tougher Plants

Beating Stress by Protecting Photosynthesis in Genetically Modified Plants


Robin Pals-Rylaarsdam
College of Arts and Sciences
Saint Xavier University
Monica L. Tischler
Department of Biological Science
Benedictine University


This "clicker case" follows two recent college graduates as they look for scientific answers to explain why the plants on their new tomato farm are not doing well. Working with their agricultural extension agent, they explore the scientific literature and learn how cold, heat, and salt can stress plants. They also learn that plants genetically engineered to produce glycine betaine, a modified amino acid, can withstand the environmental conditions that stress many agricultural plants. In their explorations, the fledgling farmers read graphs from the primary literature and review photosynthetic processes from their introductory biology course. The case consists of a PowerPoint presentation with embedded multiple-choice questions that students answer using clickers.  Developed for a first-year class in biology, it could be used in any lower-level college biology class or potentially an advanced biology class in high school. The case is also accompanied by an optional PowerPoint presentation (see "Supplemental Materials" tab above).


  • Introduce primary sources of biological information.
  • Begin to read and interpret basic graphs.
  • Connect the primary literature to basic biology processes.
  • Reinforce the steps of photosynthesis, particularly the light-dependent reactions.


Genetic engineering; genetically modified organism: GMO; chemiosmosis; photosynthesis; photosytem II; proton motive force; transmembrane protein; thylakoid; glycine betaine ; graph reading; data analysis

Topical Areas


Educational Level

High school, Undergraduate lower division


PDF, PowerPoint

Type / Methods

Clicker, Interrupted, Journal Article



Subject Headings

Biology (General)  |   Biotechnology  |   Botany / Plant Science  |   Agriculture  |  

Date Posted


Teaching Notes

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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.

Supplemental Materials

An optional PowerPoint presentation with the graphs from the cases as well as clicker questions corresponding to the questions in the case is included in Supplemental Materials for instructors who would like to teach the case using these technologies.

  Tougher Plants Power Point

Answer Key

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