Students often find it challenging to learn about complex and abstract biological
processes. Using the engineering design process, which involves designing,
building, and testing prototypes, can help students visualize the processes and
anchor ideas from lab activities. We describe an engineering-design-integrated
biology unit designed for high school students in which they learn about the
properties of slime molds, the difference between eukaryotes and prokaryotes,
and the iterative nature of the engineering design process. Using the engineering
design process, students were successful in quarantining the slime mold from the
non-inoculated oats. A t-test revealed statistically significant differences in
students’ understanding of slime mold characteristics, the difference between
eukaryotes and prokaryotes, and the engineering design process before and after
the unit. Overall, students demonstrated sound understanding of the biology core
ideas and engineering design skills inherent in this unit.
Key Words: Engineering design; slime mold; high school; integration.
Current science education standards call for the integration of engineering design into science instruction (NGSS Lead States, 2013).
According to the National Research Council (2009), integrating engineering design into science instruction provides the following benefits
to students: improved learning and achievement in science and mathematics; increased awareness of engineering and the work of engineers; an understanding of, and ability to engage in, engineering
design; enhanced interest in pursuing engineering as a career; and
increased technological literacy (pp. 49–50). Despite these benefits,
there are still very few examples of engineering-design-integrated biology lessons and units for teachers to use in their classrooms. We have
been developing and testing engineering-design-integrated science
units and activities for middle and high school science classrooms.
Here, we describe one of these units, which we have developed and
implemented in ninth- and tenth-grade advanced and honors biology
classes. This unit was taught at the beginning of the school year to
build foundational knowledge for engineering design and biology
This unit originally existed for students to gain a deeper understanding of the scientific method and basic biological principles
through structured inquiry in creating mazes for the slime mold
Physarum polycephalum to solve. However, when reflecting on the
unit, it became evident that it lacked various aspects of inquiry, as
students were made aware of the outcome prior to beginning the
lab. While students enjoyed this hands-on approach to learning,
we realized that the unit and already-available materials could lend
themselves to teaching the engineering design process, as well as
provide deeper understanding of the scientific method and foundational biological principles such as characteristics of slime molds.
Instead of having students build mazes, we created an authentic
problem for students to solve in which the slime mold modeled an
infectious disease that needed to be quarantined in order to save
the world’s population.
What Is a Slime Mold?
Despite its name, a slime mold is an amoeboid protozoan, not a
mold or fungus (Waggoner & Speer, 2006). It is a eukaryote and
thus has membrane-bound organelles. Slime molds begin their lives
as amoeba-like cells and emit chemical signals, which allow the cells
to come together as plasmodia. The chemical signals also allow the
mass of cells to “reunite” when separated. Slime molds typically live
in soil among deciduous logs or on the forest floor. They feed on
microorganisms that live in dead plant material.
Ideal for use in the classroom, slime molds exist in both an
inactive state (sclerotia) and an active state (plasmodial stage). The
sclerotia can remain viable for long periods if kept in a dark, dry,
room-temperature-controlled environment. Once ready, the sclerotia
can be activated in an agar-filled Petri dish and will survive on a
diet of oats. Its relatively low maintenance nature, inexpensive diet,
The American Biology Teacher, Vol. 81, No. 8, pp. 570–576, ISSN 0002-7685, electronic ISSN 1938-4211. © 2019 National Association of Biology Teachers. All rights
reserved. Please direct all requests for permission to photocopy or reproduce article content through the University of California Press’s Reprints and Permissions web page,
www.ucpress.edu/journals.php?p=reprints. DOI: https://doi.org/10.1525/abt.2019.81.8.570.
Slime Mold Quarantine:
• TAYLOR HOLDER, LAURA POTTMEYER,