What can we learn from worms? How the nematode C. elegans maintains balance in a changing environment

C. elegans is a well-studied model organism used in research on genetics, development, and behavior. In this unit, students conduct an experiment comparing the effect of elevated salt in the environment on wild type worms and a mutant that is resistant to higher salt concentrations (or osmolarity, referred to as an OSM strain). Through this hands-on unit, students set up the experiment, make observations, analyze their results and other scientific evidence, and develop a model that explains their results. These activities guide students in learning how worms maintain homeostasis in an unfavorable environment caused by high osmotic stress and help them build an understanding of how genes and environment interact to determine traits.

This curriculum supports the Next Generation Science Standards (NGSS) with particular emphasis on high school disciplinary core ideas LS1.A feedback mechanisms maintain internal conditions and mediate behavior, LS3.B how environmental factors affect expression of traits, and LS4.B how trait variation leads to differences in performance among individuals. Student also participate in science and engineering practices and are exposed to crosscutting concepts throughout the unit. Each lesson provides connections to the three dimensions of the NGSS.

Download the following materials here:

What can we learn from worms? one-page overview

Entire What can we learn from worms? curriculum

Accompanying PowerPoint

Materials list and instructions for maintaining worm stocks

Want to know how to chunk worms? Ayah will show you how.

Short videos showing wild type and mutant worms on high and low salt at different time points can be found here: (Videos best viewed using Internet Explorer)

Time Wild type
on low salt
Wild type
on high salt
on low salt
on high salt
15 min View View View View
24 hour View View View View
48 hour View View View View

University of Washington Department of Genome Sciences
Education Outreach, Box 355065 ~ Foege Building, Room S-334 ~ Seattle, WA 98195
phone: (206) 616-4538 fax: (206) 685-7301