Shaping Abstract Genetics Concepts into Concrete, Accessible Knowledge

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Categories: GSI Online LibraryTeaching Effectiveness Award Essays

by Jingxun Chen, Molecular and Cell Biology

Teaching Effectiveness Award Essay, 2018

Challenge: Genetics is a difficult subject for many students because of its abstract concepts. In other MCB classes, students often learn biology through descriptive narratives—each step of a cellular process is drawn out, organisms’ morphologies are compared, or the crystal structure of a protein is detailed. However, the classical genetic “rules” work like math logics; they allow one to group things, deduce the order of events, and build models, but don’t have specific forms or images. To our biology students and biologists who are used to the principle that “seeing is believing,” the rules of Genetics seem intangible and confusing, particularly in terms of what these rules mean and how they should be applied. Not surprisingly, I often hear students crying out “I’m confused, but I don’t know what I’m confused about.” Given the abstract nature of Genetics, the hard part is to help students “see” the concepts so that they can better understand them.

Solution and Assessment: Through two years of trial and error in teaching Genetics, I settled on an “AAA” strategy: (make) analogy-apply-assemble. In my first step, I used real-life visual analogies to introduce concepts. A good analogy comes from everyday objects or scenarios that are familiar to students. For example, to explain “activator” vs. “repressor,” I drew a car in section and explained that an activator acts like an engine to make a car move (i.e., to make a biological process occur), while a repressor works, like a set of brakes, to make a car stop. I like these real-life analogies because the images of a car, a plane, or a basketball game contextualized the concept, and allowed students to transpose a new concept in Genetics into concepts that were familiar. This familiarity drew them in and created “aha” moments that helped them—especially those who felt lost—gain confidence that they could learn Genetics. Indeed, when I asked students if this analogy made sense, many nodded with a smile. Several also noted in my teaching evaluations that “concepts were made easier to understand.”

My second step is to apply the concepts. Although the rules of Genetics are not physical objects, they take form in our mind when we apply them to solve specific questions, because the problem-solving process is drawn from the rules themselves. Therefore, I carefully designed practice questions so that they ranged from easy to hard, and used several rules that were easily confused by students. In sections, I would first guide the class to solve the basic application questions and ask students to discuss the challenging ones (e.g., compare/contrast concepts) in groups while I walked around. Then I invited each group to sum up their discussion, and I wrote the key points on the board. As students told me in office hours, they understood the concepts better by seeing how the concepts were applied—and differentially applied—given specific biological contexts. In my teaching evaluations, 36/38 students rated 7/7, agreeing that “the concepts were explained clearly;” over 10 students noted that the section materials were helpful.

Lastly, physicist Richard Feynman once said, “What I cannot create, I do not understand.” In other words, one of the best ways to understand something is to create it or assemble it. I assigned each group homework to create their own questions for a concept. Here, I emphasized creativity (e.g., weird symbols/organisms), so that students would build the concept into different forms. Their questions blew me away! For instance, one group “invented” an enzyme named “bear-ase” that metabolized the sugar “oski-ose,” created a trait table for two mutants (A- and B-), and asked what kinds of regulators A and B were. This question effectively tested the concept of classifying a gene as an “activator” or “repressor,” while showing a clever Cal-style! Students’ enhanced engagement with the materials was reflected by the creativity and thoughtfulness of their questions, which, according to the evaluations, pushed them to “engage with learning in a different way,” and made them “look a lot more in detail into the subject.” Their performance on exams also supported the effectiveness of the “AAA” strategy overall. Excitingly, these creative questions now become the extra practice questions, or the extra “forms” of the concepts, for future MCB 140 students to learn Genetics!