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Osmosis is Serious Business!


Troy R. Nash
Department of Biology
Presbyterian College


This directed case study involves two “stories,” each one concerned with some aspect of osmosis in living cells. Part I is centered around the effects of a hypertonic environment on plant cells, while Part II focuses on the effects of a hypotonic environment on human cells. After reading the parts, students working in small groups evaluate the information and answer the corresponding questions. This case was designed for use in a non-majors biology course, but could be adapted for use in a majors’ introductory biology course or a high school biology class.

  • Understand solute concentration and the process of osmosis.
  • Be able to determine the net direction of osmosis in a given situation.
  • Understand osmosis in plant cells and be able to apply the term plasmolysis.
  • Understand osmosis in animal cells and be able to apply the term lysis.
Keywords: Osmosis; diffusion; tonicity; hypertonic; hypotonic; lysis; plasmolysis; blood cells; fertilizer
Topical Area: N/A
Educational Level: High school, Undergraduate lower division
Formats: PDF
Type/Method: Directed
Language: English
Subject Headings: Biology (General)   Cell Biology   Physiology   Botany / Plant Science  
Date Posted: 12/15/08
Date Modified: N/A
Copyright: Copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State University of New York. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.

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